The ability of a native predator to adjust to a dangerously toxic invasive species is key to avoiding an ongoing suppression of the predator's population and the trophic cascade of effects that can result. Many species of anurophagous predators have suffered population declines due to the cane toad's (Rhinella marina: Bufonidae) invasion of Australia; these predators can be fatally poisoned from attempting to consume the toxic toad. We studied one such toad-vulnerable predator, the yellow-spotted monitor (Varanus panoptes: Varanidae), testing whether changes to the predator's feeding behaviour could explain how the species persists following toad invasion. Wild, free-roaming lizards from (1) toad-naïve and (2) toad-exposed populations were offered non-toxic native frogs and slightly toxic cane toads (with parotoid glands removed) in standardized feeding trials. Toad-naïve lizards readily consumed both frogs and toads, with some lizards displaying overt signs of illness after consuming toads. In contrast, lizards from toad-exposed populations consumed frogs but avoided toads. Repeated encounters with toads did not modify feeding responses by lizards from the toad-naïve populations, suggesting that aversion learning is limited (but may nonetheless occur). Our results suggest that this vulnerable predator can adjust to toad invasion by developing an aversion to feeding on the toxic invader, but it remains unclear as to whether the lizard's toad-aversion arises via adaptation or learning.

Understanding an organism's home range is an important component of effective wildlife management. However, home ranges can vary spatially and temporally within and between populations. Landscape ecology theory can provide a framework for understanding spatio-temporal variability in animal traits. We used radio-telemetry in a population of diamond python Morelia spilota spilota Lacépède (Pythonidae) from a biologically rich and structurally heterogeneous reserve in eastern Australia to explore the relationship between home range size, optimal foraging theory and vegetation mosaic theory. Twelve adult snakes were tracked between September 2004 and February 2008. Male home ranges were significantly larger (P < 0.05) and more variable (41 ± 30 ha) than female home ranges (23 ± 5 ha), and males moved further between observations (123 m c.f. 65 m). Core activity centres varied significantly among habitat (P < 0.05) with larger home ranges observed in heathland, a vegetation community which supported comparatively low mammal diversity. No other variables examined including number of fixes, body length, prey abundance, vegetation heterogeneity or fire history explained home range variability. In this system, relatively high mammalian prey diversity and rapid post-fire vegetation succession may limit prey availability and fire effects as being significant determinants of home range variability in M. spilota.

The diversity of responses to episodic rainfall events among perennial plant species is critical for the maintenance of ecosystem functions in arid systems. We use a litter fall study to capture the responses of three species to shifts in environmental conditions. We examined the effects of landform, rainfall and other meteorological variables (temperature, evaporation, relative humidity, solar exposure, wind speed and cloud cover) on the mass of reproductive structures falling from two shrubs (Senna artemisioides ssp. filifolia, Acacia burkittii) and one tree (Eucalyptus gracilis) species in a eucalypt mallee woodland in semi-arid eastern Australia. Data were collected over three years. The first year received below-average rainfall and the following years received about twice the average annual rainfall. We assessed the relative importance of our explanatory variables, for each species separately, comparing the results using two methods: (1) multi-model inference of a zero-inflated negative binomial generalized linear model, and (2) structural equation modelling. Multi-model inference showed rainfall frequency, at species-specific lag intervals, to be of highest relative importance for all three species. Wind speed was also relatively important for all three species. Structural equation modelling supported these results, with strong, direct path coefficients for the number of days of rainfall in the past 12 months. There was, however, no strong effect of the average rainfall event size. Our analyses demonstrate the strong, direct and positive effect of rainfall, and highlight the importance of rainfall frequency rather than rainfall event size. Furthermore, we found species-specific responses to environmental variables associated with wind, solar exposure and landform, further driving the litter fall of reproductive structures in perennial plants in semi-arid environments. Understanding how different species respond to rainfall and other meteorological conditions can give us greater insights into the capacity of these systems to adapt, which will be important in a changing climate.

Tree hollows are a critical but diminishing resource for a wide range of fauna around the world. Conservation of these fauna depends on sustainable management of tree species that produce the hollows on which they depend. This study addressed the need for empirical data about intraspecific and interspecific variation in hollow occurrence and abundance in woodland trees in Australia. We measured and performed hollow surveys on 1817 trees of seven species of woodland Eucalyptus in central-western New South Wales, Australia. Trees were surveyed at 51 one-hectare sites and about 30% of trees surveyed had multiple stems. Generalized linear mixed models that accounted for nestedness of stems within trees and trees within sites detected a significant amount of variation in hollow occurrence and abundance. Models for individual tree stems of live trees showed hollow probability and abundance increased with diameter at breast height (DBH) and with increasing senescence (form). Stems of Eucalyptus microcarpa Maiden had a higher probability of having hollows than similar DBH stems of Eucalyptus camaldulensis Dehnh., Eucalyptus melliodora A.Cunn. ex Schauer or Eucalyptus populnea ssp. bimbil L.A.S.Johnson & K.D.Hill. Dead stems in live trees were more likely to have hollows than live stems of similar DBH. Each stem in a multi-stemmed tree had a lower probability of hollow occurrence and lower abundance of hollows than single-stemmed trees of similar DBH. For stems of dead trees, hollow occurrence and abundance increased with DBH and differed depending on stage of senescence. A comparison of our data with other studies indicates regional variation of hollow abundances within tree species.

The transition from a species introduction to an invasion often spans many decades (a lag phase). However, few studies have determined the mechanisms underlying lag phases. Such a mechanistic understanding is vital if the potential ecosystem-level impacts are to be predicted and the invasion risks to be managed proactively. Here we examine Banksia ericifolia, introduced for floriculture to South Africa, as a case study. We found 18 sites where the species has been planted, with self-sustaining (naturalized) populations at four sites, and an invasive population at one site. The invasion originated from around 100 individuals planted 35 years ago; after several fires this population has grown to approximately 10 000 plants covering about 127 ha. The current invasion of B. ericifolia already has ecosystem-level impacts, for example the nectar available to bird pollinators has more than doubled, potentially disrupting native pollination networks. If fires occurred at the other naturalized sites we anticipate populations would rapidly spread and densify with invaded areas ultimately become banksia-dominated woodlands. Indeed the only site other than the invasive site where fire has occurred regularly is already showing signs of rapid population growth and spread. However, recruitment is mainly immediately post fire and no seed bank accumulates in the soil, mechanical control of adult plants is cheap and effective, and immature plants are easily detected. This study is a first in illustrating the importance of fire in driving lag phases and provides a valuable example for why it is essential to determine the mechanisms that mediate lag phases in introduced plant species. Serotinous species that have been introduced to areas where fire is suppressed could easily be misinterpreted as low risk species whilst they remain in a lag phase, but they can represent a major invasion risk.

Predation risk influences foraging decisions and time allocation of prey species, and may result in habitat shifts from potentially dangerous to safer areas. We examined a wild population of western grey kangaroos (Macropus fuliginosus) to test the efficacy of predator faecal odour in influencing time allocated to different behaviours and inducing changes in habitat use. Kangaroos were exposed to fresh faeces of a historical predator, the dingo (Canis lupus dingo), a recently introduced predator, the red fox (Vulpes vulpes), a herbivore (horse, Equus caballus) and an unscented control simultaneously. Kangaroos did not increase vigilance in predator-scented areas. However, they investigated odour sources by approaching and sniffing; more time was spent investigating fox odour than control odours. Kangaroos then exhibited a clear anti-predator response to predator odours, modifying their space use by rapidly escaping, then avoiding fox and dingo odour sources. Our results demonstrate that wild western grey kangaroos show behavioural responses to predator faeces, investigating then avoiding these olfactory cues of potential predation risk, rather than increasing general vigilance. This study contributes to our understanding of the impact of introduced mammalian predators on marsupial prey and demonstrates that a native Australian marsupial can recognize and respond to the odour of potential predators, including one that has been recently introduced.

Climate change is recognized as a major threat to biodiversity. Multidisciplinary approaches that combine population genetics and species distribution modelling to assess these threats and recommend conservation actions are critical but rare. Combined, these methods provide independent verification and a more compelling case for developing conservation actions. This study integrates these data streams together with field assessments and spatial analyses to develop future genetic resource management recommendations. The study species was Callistemon teretifolius (Needle Bottlebrush), a shrub species endemic to the Mount Lofty and Flinders Ranges, South Australia, and potentially vulnerable to climate change. Chloroplast microsatellite and Amplified Fragment Length Polymorphism data were combined with species distribution modelling (MaxEnt), spatial analysis and field assessment to evaluate climate change vulnerability. Two major genetic groups were identified (Mount Lofty and Flinders Ranges). Populations in the Flinders Ranges, especially the Southern Flinders Ranges exhibited the highest genetic diversity, indicating a possible genetic refugium. Lower genetic diversity to the south in the Mount Lofty Ranges and north in the Gammon Ranges may be due to post-glacial expansion into these areas from the Flinders Ranges or loss of alleles. Low levels of contemporary gene flow were identified, which suggests Callistemon teretifolius may have a limited capacity to respond to climate change through migration. Range restrictions were predicted for all future climates, especially in the north. It is likely that C. teretifolius will be adversely affected by climate change, due to limited gene flow, predicted range restriction and loss of suitable habitat. The Southern Flinders Ranges should be a priority for conservation because it contains the highest number of individuals and genetic diversity. We recommend monitoring and adaptive management involving restoration in the Southern Flinders Ranges, potentially incorporating genetic translocations from other areas to capture diversity, to assist C. teretifolius to adapt to climate change.

Cities are heterogeneous landscapes, with remnant vegetation interspersed amongst areas designed for human use. Native wildlife remaining in urban areas are only likely to thrive and persist if they incorporate human altered areas into what they perceive as habitat. Many sensitive species may be lost if they are restricted to remnant vegetation, and cannot use the urban matrix. In this study, we quantify spatial aspects of the ranging behaviour of Gould's long-eared bat (Nyctophilus gouldi) using radio-telemetry and acoustic surveys to determine use of the suburban–bushland interface. This species represents a group prone to extinction due to biological attributes that adapt it to flight within cluttered vegetation, making it more specialized. We radio-tracked 19 individuals in Cumberland State Forest (CSF), a 40-ha remnant located in north-west Sydney, New South Wales, Australia. The nightly range (95% Kernel Density Estimator) was small and localized, and was no greater than 80 ha, where individuals moved on average less than 300 m from roosts each night. All individual N. gouldi tracked used bushland in an almost obligate manner, where up to 100% of used habitat was within local bushland, with little to no use of areas classified as ‘urban’ (residential, commercial and educational land uses). Small open spaces exposed to artificial lighting within the main ranging area of CSF had significantly lower activity (bat passes) of Nyctophilus spp. and significantly higher activity of other species more tolerant of urbanization (P < 0.05). Our results demonstrate that artificial lighting can ‘spill-over’ into bushland and alter the use of preferred habitat. We conclude that large patches (>40 ha) of protected remnant vegetation must be managed to reduce further degradation, and smaller isolated patches could be restored to provide habitat, particularly in narrow bushland corridors, to assist these species to tolerate urban areas.

Habitat modification and invasive species are significant drivers of biodiversity decline. However, distinguishing between the impacts of these two drivers on native species can be difficult. For example, habitat modification may reduce native species abundance, while an invasive species may take advantage of the new environment. This scenario has been described as the driver-passenger model, with ‘passengers’ taking advantage of habitat modification and ‘drivers’ causing native species decline. Therefore, research must incorporate both habitat modification and invasive species impact to successfully investigate native species decline. In this paper, we used the common myna (Acridotheres tristis) as a case study to investigate the driver-passenger model. We investigated changes in bird abundance, over 2 years, in relation to different habitat types and common myna abundance. We hypothesized that the common myna is both a passenger of habitat change and a driver of some bird species decline. Our results indicated that the abundance of many native species is greater in high tree density nature reserves, while the common myna was uncommon in these areas. Common myna abundance was almost three times higher in urban areas than nature reserves and declined rapidly as tree density in nature reserves increased. Our findings indicated that the common myna is primarily a passenger of habitat change. However, we also observed negative associations between common myna abundance and some bird species. We stress the importance of simultaneously investigating both invasive species impact and habitat modification. We suggest habitat restoration could be a useful tool for both native species recovery and invasive species control. Understanding the drivers of native species decline will help inform impact mitigation and direct further research.

The east-coast free-tailed bat Mormopterus norfolkensis Gray, 1839 is a threatened insectivorous bat that is poorly known and as such conservation management strategies are only broadly prescribed. Insectivorous bats that use human-modified landscapes are often adapted to foraging in open microhabitats. However, few studies have explored whether open-adapted bats select landscapes with more of these microhabitat features. We compared three morphologically similar and sympatric, molossid bats (genus Mormopterus) with different conservation status in terms of their association with vegetation, climate, landform and land-use attributes at landscape and local habitat element scales. We predicted that these species would use similar landscape types, with semi-cleared and low density urban landscapes used more than forested and heavily cleared landscapes. Additionally, we explored which environmental variables best explained the occurrence of each species by constructing post-hoc models and habitat suitability maps. Contrary to predictions, we found that the three species varied in their habitat use with no one landscape type used more extensively than other types. Overall, M. norfolkensis was more likely to occur in low-lying, non-urban, riparian habitats with little vegetation cover. Mormopterus species 2 occupied similar habitats, but was more tolerant of urban landscapes. In contrast, Mormopterus species 4 occurred more often in cleared than forested landscapes, particularly dry landscapes with little vegetation cover. The extensive use of coastal floodplains by the threatened M. norfolkensis is significant because these habitats are under increasing pressure from human land-uses and the predicted increase in urbanization is likely to further reduce the amount of suitable habitat.

Several ecological and evolutionary processes can drive changes in diversity at different spatial scales. To determine the scale at which these processes are most influential, we hypothesized that (i) broad-scale differences between ecoregions had greater influence on ant species richness and species turnover than local differences among fragments within ecoregions; and (ii) the degree of dissimilarity in ant species composition is larger between Tropical Dry Forest fragments and the surrounding vegetations than among Tropical Dry Forests located in different ecoregions, indicating that extant Tropical Dry Forests are relicts of a broader distribution of this vegetation. To examine ant diversity patterns, we built a nested hierarchical design on three spatial scales, ranging from fragments (local scale), Tropical Dry Forest + surroundings vegetation (landscape scale) and Brazilian ecoregions (regional scale). We used 450 sampling units (45 sampling units × two fragments × five ecoregions = 450). A null model based on the sample was used to identify variations in the random distribution across spatial scales. Spatial partitioning of ant diversity showed that observed β₁ diversity (between fragments) and β₂ diversity (among ecoregions) were higher than expected by chance. When the partitioning was analysed separately for each region, the observed β₁ diversity (Tropical Dry Forest and surrounding vegetation) was higher than expected by the null hypothesis in all ecoregions of Brazil. Based on species composition and diversity patterns, we stress the importance of creating more protected areas throughout the coverage area of Tropical Dry Forests, favouring a more efficient conservation process.

Climate change models predict that Australia's alpine areas will experience major declines in snow cover, which, in turn, may provide suitable habitat for species presently restricted to lower altitudes. As a result, there are concerns among land managers that many species will invade alpine areas and have a detrimental impact on fragile alpine ecosystems. However, species survival in such areas, irrespective of snow cover, is greatly dependent on the availability of suitable resources. This study investigated the selection of resources by common wombats Vombatus ursinus, which are currently restricted to, but widespread throughout, the subalpine zone of the Snowy Mountains. Our objectives were to identify habitat choices, and build a model of habitat suitability over the broader landscape, to investigate the likelihood of this common herbivore inhabiting the alpine zone. Global positioning system data were obtained from collared wombats, which were tracked for up to a year, to examine resource selection. Resource selection within the home range of individual wombats revealed that topographic position, vegetation cover, drainage, past fire disturbance, and roads were important predictors of locations. A global model showed that wombats selected locations with mid-elevations, moderate slopes, closer to water courses and roads, and with a lower proportion of grassland, which are discussed in relation to foraging and burrowing requirements. Mapping of the global model illustrated that alpine areas had a low relative probability of use by this species. Consequently, wombats are unlikely to inhabit alpine areas under given climate change scenarios of less snow cover, because the area (presently) does not contain suitable resources necessary for a wombat to maintain a home range. Researchers and managers need to be mindful of how the spatial distribution of resources, in addition to species climatic tolerances, will influence potential range shifts.

Agroecosystems are increasingly recognized as both sources and sinks of non-native weedy plant species as well as of native plant species, thus management of these systems has important implications for the composition of plant communities and landscape diversity. We quantified the distribution and abundance of both native and non-native plant species along a habitat gradient representing four management zones: managed agroecosystem, the agroecosystem boundary, ecotone, and neighbouring native forest for two land uses: kiwifruit orchards and neighbouring grassland agroecosystems. Native plant species diversity was highest in forest zones, and declined significantly with increasing non-native plant diversity across all management zones. The negative relationship between native and non-native plant species richness and diversity across all management zones was surprising, and contrasts with most ecological literature. Further, non-native plant species that have the largest ecological or ecosystem impacts were most abundant in ecotones, but were largely absent from managed zones and their margins. Our results suggest that agroecosystems and neighbouring vegetation can harbour native species, but can also be a source of non-native invasive weeds. These results highlight that agricultural margins contain both native plant diversity and environmental weeds, and that management of these margins affects diversity both on and off the farm.

We present the first quantification of forest community composition and its relationship with environmental factors in South American subtropical Atlantic Forests. In this region, rain, seasonally dry and mixed forests form an ecotonal zone near the parallel of latitude 30°S. To investigate how well current knowledge on climatic effects and biogeographic distribution apply to subtropical ecotones, we tested the following expectations: (i) there is a floristic longitudinal gradient correlated to altitudinal and climatic gradients; (ii) climatic variables are more important than soil factors in shaping floristic composition; and (iii) there are three floristic regions in the southernmost limit of the Atlantic Forest biome that are expected to be distinct in composition, structure and biogeographical origin. We examined floristic composition and its relationship with environmental factors across 52 1-ha permanent study areas in subtropical Brazil, containing in total 269 tree species ≥ 9.5 dbh (diameter at breast height). Climatic data, related to rainfall seasonality and temperature, as well as soil properties, were compiled from published sources or global data banks. Expectations one and two were confirmed, but expectation three was only partially met. Hierarchical cluster analysis divided the southernmost Atlantic Forests into four major groups (Rain, Seasonally Dry, Western Mixed and Eastern Mixed Forests). Overall, the tested environmental variables differed significantly among the four regions. Using indicator species analysis, we distinguished 46 indicator species, which had significant environmental preferences for one floristic region. These species can be used as indicators of environmental conditions or to determine to which floristic region a certain forest belongs. Biogeographic distributions differed between floristic groups, supporting the interpretation that Eastern Mixed Forests are relict forests of a temperate forest of Andean origin that occurred during colder palaeoclimates. Western Mixed Forests represent the main floristic ecotone between Seasonally dry and Eastern Mixed Forests.

Environmental factors play an integral role, either directly or indirectly, in structuring faunal assemblages. Water chemistry, predation, hydroperiod and competition influence tadpole assemblages within waterbodies. We surveyed aquatic predators, habitat refugia, water height and water chemistry variables (pH, salinity and turbidity) at 37 waterbodies over an intensive 22-day field survey to determine which environmental factors influence the relative abundance and occupancy of two habitat specialist anuran tadpole species in naturally acidic, oligotrophic waterbodies within eastern Australian wallum communities. The majority of tadpoles found were of Litoria olongburensis (wallum sedge frog) and Crinia tinnula (wallum froglet) species, both habitat specialists that are associated with wallum waterbodies and listed as Vulnerable under the IUCN Red List. Tadpoles of two other species (Litoria fallax (eastern sedge frog), and Litoria cooloolensis (cooloola sedge frog)) were recorded from two waterbodies. Tadpoles of Litoria gracilenta (graceful treefrog) were recorded from one waterbody. Relative abundance and occupancy of L. olongburensis tadpoles were associated with pH and water depth. Additionally, L. olongburensis tadpole relative abundance was negatively associated with turbidity. Waterbody occupancy by C. tinnula tadpoles was negatively associated with predatory fish and water depth and positively associated with turbidity. Variables associated with relative abundance of C. tinnula tadpoles were inconclusive and further survey work is required to identify these environmental factors. Our results show that the ecology of specialist and non-specialist tadpole species associated with ‘unique’ (e.g. wallum) waterbodies is complex and species specific, with specialist species likely dominating unique habitats.

Demographic and ecophysiological data for the endangered New Caledonian conifer, Araucaria muelleri (Araucariaceae), were analysed to: (i) evaluate population viability in relation to site conditions and human impacts; and (ii) advance our understanding of how stress-tolerator plant functional traits affect the population dynamic behaviour and conservation requirements of long-lived tree species. Growth, survivorship and recruitment in four A. muelleri populations were monitored across 9 years. Demographic rates were analysed using stage-based transition matrices. Leaf δ¹³C, %N and photosystem II stress (Fv/Fm) were measured for seedlings, saplings and trees, and leaf mass per area (LMA) for trees, and correlations among ecophysiological and demographic variables explored. Seedling, sapling and tree stem growth were among the slowest, and annual survivorship among the highest, reported for any tree. Transition matrix analyses yielded stable estimated population growth rates, λ, not significantly different from 1.0 for all populations. Leaf δ¹³C was positively correlated with seedling and sapling height growth, while daytime photosystem II stress (Fv/Fm) was high in seedlings, but low in saplings and trees. Ecophysiological measures suggest that individuals transition from moisture-limited growth at the seedling stage to nutrient-limited growth as adults. High levels of environmental stress result in slow stand dynamics, characterized by low recruitment and growth rates counterbalanced by equally low mortality rates. These dynamics result in populations with limited capacity to increase in size quickly, but potentially highly vulnerable to decline should the rate of adult mortality increase. This combination of traits is likely typical of extreme stress-tolerator woody species and suggests a conservation focus on the preservation of mature individuals.

Invasive species can induce shifts in habitat use by native taxa: either by modifying habitat availability, or by repelling or attracting native species to the vicinity of the invader. The ongoing invasion of cane toads (Rhinella marina) through tropical Australia might affect native frogs by affecting refuge-site availability, because both frogs and toads frequently shelter by day in burrows. Our laboratory and field studies in the wet-dry tropics show that native frogs of at least three species (Litoria tornieri, Litoria nasuta and Litoria dahlii) preferentially aggregate with conspecifics, and with (some) other species of native frogs. However, the frogs rarely aggregated with cane toads either in outdoor arenas or in standardized experimental burrows that we monitored in the field. The native frogs that we tested either avoided burrows containing cane toads (or cane toad scent) or else ignored the stimulus (i.e. treated such a burrow in the same way as they did an empty burrow). Native frogs selected a highly non-random suite of burrows as diurnal retreat sites, whereas cane toads were less selective. Hence, even in the absence of toads, frogs do not use many of the burrows that are suitable for toads. The invasion of cane toads through tropical Australia is unlikely to have had a major impact on retreat-site availability for native frogs.

In dry ecosystems, water supply is highly variable in time and space, occurring either as short pulses of shallow soil water or long phases of deep soil water. There may be correspondence between hierarchical soil water pulses and hierarchical biological responses, but this has not been directly tested for arid Australia. We compared plant community responses to an isolated short rain pulse (about 130 mm, November 2008) versus the start, mid and later stages of an extended high rainfall phase (about 540 mm, February 2010 to March 2011) at a site on the western edge of the Simpson Desert. We sampled across contrasting habitats: tall longitudinal sand ridges and adjacent stony clay plains (gibber). Thus, we compared responses to spatially variable soil moisture availability (sand vs. clay soil; run-off/on relief) and temporally variable rainfall supply. Our results supported the hierarchical resource pulse-biological response concept for dry ecosystems, with the short and long rainfall phases modulating distinct responses among functional types. Shallow-rooted annual grasses showed an equivalent positive response to the isolated pulse as to the first pulse of the high rain phase; whereas short-lived forbs, longer-lived (2–3 years) grasses and persistent forbs had peak abundance during the high rainfall phase. Perennial grass and shrub productivity did not change over time, though there was a distinct trend towards heightened sexual reproduction at the mid-late stages of the high rain phase. We also found that species seasonal growth tendencies were pronounced, and that spatial aspects of moisture availability resulted in different composition patterns at the habitat scale with the gibber and sand ridge sites showing strong and weak correspondence with temporal rainfall patterning respectively. Thus, we confirm that plant productivity models for this region should include the effects of rainfall connectivity and soil texture as well as species seasonal growth constraints and rooting attributes.

The evolution of a particular trait or combination of traits within lineages may affect subsequent evolutionary outcomes, leading closely related species to exhibit higher phenotypic similarity than expected under a simple Brownian-motion evolutionary model. Niche theory postulates that phenotypes determine species distribution across environmental gradients, leading to a phylogenetic signature in the community assembly. Thus, the incorporation of species phylogeny in the analysis of community ecology structure allows one to link broader environmental, spatial and temporal factors to local, small-scale ecological processes, thus enabling understanding of community assembly patterns in a broader context. We used the net relatedness index to assess phylogenetic structure within avian communities across a harshness gradient in coastal habitats in southern Brazil. We also evaluated phylogenetic beta diversity, to test whether closely related species exploit habitats with similar environmental conditions. In order to do so, we scaled up phylogenetic information from the species to site level using phylogenetic fuzzy weighting. We found a pattern of phylogenetic clustering in less-vegetated habitats, namely sandy beach and dunes, which are subject to harsher conditions because of proximity to the ocean. Basal lineages were associated with the more structurally homogeneous sandy beach, while late-divergence clades occurred in more complex habitats, which were positively related to vegetation cover and height. The observed pattern of phylogenetic clustering suggested the importance of harsh conditions in constraining the distribution of avian lineages. Furthermore, contrasting environmental features between habitats influenced phylogenetic variation, demonstrating the prevalence of phylogenetic habitat filtering. From an applied point of view, such as planning and management of biological reserves, we showed that the full array of habitat patches embedded within coastal ecological gradients must be included in order to preserve distinct evolutionary lineages.

Species composition and productivity of natural grasslands are influenced by soil nutrient status. With high resource availability, productivity is expected to increase, and competition is assumed to gain prominence with predicted exclusion of species of lower competitive ability. During 2010 and 2011 we used the dry weight rank method to measure above-ground phytomass production of herbage in 96 plots (9 m × 2.7 m) fertilized for 60 years with two forms of nitrogen (N as limestone ammonium nitrate or ammonium sulphate at four levels: 0, 7.1, 14.1, 21.2 g m⁻²), phosphorus (P as superphosphate at two levels: 0, 33.6 g m⁻²), and lime (two levels: 0, 225 g m⁻²). Light attenuation was measured as the proportion of photosynthetically active radiation reaching the lower leaf layers of the grasses and the ground surface. Light conditions beneath the grass layer were reduced by nutrient addition to 30% of full sunlight but remained above 60% in non-fertilized plots. Grass total above-ground phytomass production increased with nutrient addition. The strongest yield responses were attained with N plus P addition. Species responses showed that Themeda triandra and Hyparrhenia hirta decreased in above-ground phytomass production with nutrient addition while Panicum maximum, Eragrostis curvula and E. plana increased. These findings are discussed in terms of competitive interactions among species, their position in the grass canopy and their physiological tolerances to high nitrogen environments.

The spread of buffel grass (Cenchrus ciliaris) in semi-arid Australia in recent decades has substantially increased ground cover and fuel loads, particularly in open woodland vegetation communities. The resulting alteration of fire regimes may be the most significant impact of buffel invasion on ecological communities in these areas. Broad scale management of buffel grass is currently not an option in Australia but it is becoming increasingly relevant to assess the benefits of restoring areas of native vegetation where preventing buffel grass invasion is no-longer possible. We managed buffel grass in a series of experimental plots from 2008–2012. In June and August 2011, two unplanned fires burnt through the plots providing a unique opportunity to compare the outcome of wildfire, including the spatial pattern of fire, and the effect on ground vegetation and on a long-lived, perennial overstorey species, in replicated managed and unmanaged plots. The area of ground that remained unburnt was much greater in managed plots (with predominantly native vegetation) than unmanaged (predominantly buffel grass) plots and where the managed plots did burn the fire was more patchy. This had direct implications for the richness of ground layer plant taxa following fire and the extent to which overstorey trees were exposed to fire. Fire increased pre-existing differences in the number of taxa in the ground level vegetation, an effect that persisted for the duration of our study, suggesting that fire accelerates direct negative competitive effects between buffel grass and native grasses and forbs. Hakea divaricata (fork-leafed corkwood) trees in unmanaged buffel grass sites suffered higher burn intensities, and their long-term viability at this location is likely to be threatened if fires fuelled by buffel grass continue. Our results demonstrate clear benefits of removing fire-enhancing invasive plants from areas of high conservation value.

The Australian desert ant Melophorus bagoti (Formicidae) is a thermophilic, solitary foraging ant that inhabits the semi-arid regions of Australia. In recent years, it has become a model species for the study of navigation. However, its ecological traits are not well understood, especially on the level of the entire colony. Here, we investigated this species daily activity schedule and diet composition, and examined its foraging behaviour. Foraging activity is confined to a window of roughly 50–70°C soil surface temperature, and foragers reacted quickly to temperature changes. Consequently, the pattern of daily outbound traffic during summer is unimodal on warm days and bimodal on very hot days. Foragers are opportunistic scavengers; dead insects make up a large proportion of food items, but grass seeds are also occasionally brought back to the nest in large amounts. Diet composition changes with the seasonal availability of certain food groups. Melophorus bagoti foragers have the ability to recruit nestmates to profitable food sources. Recruitment seems to function without the use of pheromone trails, but the exact mechanism requires further investigation.

Theory suggests that range edge populations of invading plants and animals may experience runaway selection for increased dispersal ability. This theory has been supported by field data for cane toads in Australia, and for Senecio inaequidens in Europe. In this study, we asked whether range edge populations of Senecio madagascariensis (Asteraceae), an invasive plant in eastern Australia, displayed higher dispersal ability that did populations from the established range. We measured 1363 diaspores from 33 populations. There was no significant difference in dispersal potential between populations from the range edge, and those from the established range (P = 0.19). We also used a glasshouse study to determine whether the range edge populations differed from populations in the established range in three critical life history traits: germination success, plant size and time to first reproduction. The only significant difference was for higher germination in range edge populations. The null result for dispersal ability is excellent news for land managers, as this is the first published evidence that selection for ever-increasing dispersal rates is not ubiquitous in invading populations.

This study examined two models that are most frequently used to describe the relationship between species richness and productivity (SPR): monotonic positive and hump-shaped models. We assessed zooplankton community diversity in response to algal productivity. The relationship between net primary productivity (NPP) and rarefied species richness was examined by fitting the data to two models and comparing them using the Akaike information criterion (AICc). Macrophyte banks with the highest net primary productivity had the highest zooplankton abundance. Our results pointed to a hump-shaped model as the best fit to describe the relationship between zooplankton species richness and primary productivity (ΔAICc > 4). Thus, the diversity was lower at the extremes of productivity and higher at intermediate levels of productivity. We suggest that this relationship might occur because when the resource supply rates are low, environmental conditions are stressful, whereas a high availability of resources enhances competitive exclusion. Two observations supported this statement: (i) the total abundance of the community positively correlated with NPP (P < 0.05), indicating that less productive sites had few consumers and the raised productivity tended to favour the total abundance; (ii) NPP was negatively correlated with evenness (P < 0.05), indicating that productivity increased the dominance of certain species in the communities. Therefore, we challenged two of the models most frequently used to explain SPR, and discuss some mechanisms underlying a hump-shaped SPR.

Non-native mammals that are disturbance agents can promote non-native plant invasions, but to date there is scant evidence on the mechanisms behind this pattern. We used wild boar (Sus scrofa) as a model species to evaluate the role of non-native mammals in promoting plant invasion by identifying the degree to which soil disturbance and endozoochorous seed dispersal drive plant invasions. To test if soil disturbance promotes plant invasion, we conducted an exclosure experiment in which we recorded emergence, establishment and biomass of seedlings of seven non-native plant species planted in no-rooting, boar-rooting and artificial rooting patches in Patagonia, Argentina. To examine the role of boar in dispersing seeds we germinated viable seeds from 181 boar droppings and compared this collection to the soil seed bank by collecting a soil sample adjacent to each dropping. We found that both establishment and biomass of non-native seedlings in boar-rooting patches were double those in no-rooting patches. Values in artificial rooting patches were intermediate between those in boar-rooting and no-rooting treatments. By contrast, we found that the proportion of non-native seedlings in the soil samples was double that in the droppings, and over 80% of the germinated seeds were native species in both samples. Lastly, an effect size test showed that soil disturbance by wild boar rather than endozoochorous dispersal facilitates plant invasions. These results have implications for both the native and introduced ranges of wild boar, where rooting disturbance may facilitate community composition shifts.

A general understanding of the factors that regulate populations remains a central goal for ecologists, and species that increase rapidly to plague numbers followed by equally sudden crashes in abundance are particularly intriguing. Throughout central Australia, the long-haired rat, Rattus villosissimus, is largely absent in dry times, but can irrupt into plague numbers after heavy rains. Using historical data we first relate the occurrence of plagues to exceptionally high rainfalls, and using live-trapping records from rat irruptions in 1991 and 2011 in the eastern Simpson Desert, we then investigate the population structure at the plague front. In doing so, we ask if long-haired rat plagues irrupt from multiple refugia, if young males are first to disperse and whether the rate of dispersal is rapid. Annual rainfall in the year preceding a plague successfully predicted the probability of an outbreak, with an 80% chance of a plague occurring after an annual rainfall of 750 mm. Trapping grids closest to drainage lines to the south of the study area had greater captures of long-haired rats. Enhanced rat numbers in proximity to drainage areas suggested that the irruptive process unfolded from the south and demonstrated the existence of multiple refugia. In contrast to the resident fitness hypothesis, there was no difference in captures between the sexes or age-classes of long-haired rats. Heavier animals were caught at the invasion front, presumably because they could travel larger distances than smaller individuals, suggesting that larger individuals were maximizing their fitness by dispersing first to new resources. Captures of long-haired rats were highest at the beginning of the irruption in both 1991 and 2011, suggesting rapid colonization. Although rare in occurrence, rodent population irruptions and the resulting dispersal across large areas, which may persist for a few years, can thus extend the domain of influence of exceptional rain years well into the future.

Ecological interactions among invasive species can affect not only the success of the invaders, but also their impact on ecosystems in the invaded range. In Australia, both dung beetles (subfamily Scarabaeinae) and cane toads (Rhinella marina) were introduced for biocontrol: the beetles to break down bovine faeces piles (cowpats) that otherwise accumulate and reduce pasture productivity, and the cane toad to consume scarab beetles that eat sugarcane and thus reduce sugar production. The dung beetles have been a success, whereas the toads have been a failure. Our experimental studies show that as well as impacting native fauna directly, cane toads reduce the rate of cowpat breakdown by consuming dung beetles. In the laboratory, dehydrated toads actively sought out cowpats based on scent cues, and in field enclosures, the presence of a cane toad significantly reduced rates of cowpat decomposition. Although toads have benefited from agricultural activities, their spread across Australia likely has reduced the effectiveness of one of the most successful biocontrol programmes ever conducted in that continent.

Broad-scale richness gradients are closely associated with temperature and water availability. However, historical and evolutionary processes have also contributed to shape current diversity patterns. In this paper we focus on the potential influences of Pleistocene glaciation and phylogenetic niche conservatism (the tendency for traits to be maintained during diversification) on the tree diversity gradient in Chile, and we quantify its primary climatic correlates. Tree species richness is greatest at mid latitudes, particularly in the Andes and Coastal ranges, and decreases abruptly to the south and north. Regression tree analysis identified annual precipitation and annual temperature as the primary probable drivers of this gradient. Ice cover during the Last Glacial Maximum was also identified as an ‘important’ variable, but the contemporary and historical predictors are strongly collinear. Geographically weighted regression indicated that the relationships between richness and environmental variables vary regionally: the relationship between tree richness and precipitation is stronger in north-central Chile, whereas tree richness and temperature are most strongly associated in south-central Chile. By assigning each species the age of the family to which it belongs and averaging all species in each geographical unit, we also found that species from the oldest families are distributed mainly in mid to high latitudes and species from younger families are distributed mainly at lower latitudes. This pattern is closely associated with annual precipitation. Thus, the ecological component of tree richness follows contemporary climatic gradients of both energy and water, but the aridification of the Atacama Desert was an important driver over evolutionary time. The influence of recent Pleistocene glaciation remains unresolved but it cannot be discounted.

The cane toad (Rhinella marina) is one of the most successful invasive species worldwide, and has caused significant negative impacts on Australian fauna. Experimental work in the laboratory and in mesocosms has shown that tadpoles of native frogs can affect survival, size at metamorphosis and duration of larval period of cane toad tadpoles. To test if these effects occur in nature, we conducted a field experiment using two temporary ponds where we set up enclosures with tadpoles of native green tree frogs (Litoria caerulea) and cane toads in treatments with a range of densities and combinations. The presence of green tree frog tadpoles significantly decreased the growth rate of toad tadpoles and increased the duration of their larval period in both ponds; in one pond, frog tadpoles also significantly reduced the body length and mass of metamorph toads. Toad tadpoles did not have any significant negative effects on green tree frog tadpoles, but there was strong intraspecific competition within the latter species: increased frog tadpole density resulted in increased larval period and reduced survival, growth rate and size at metamorphosis for frogs at one or both ponds. Our results are encouraging for the possibility of using native frogs as one component of an integrated approach to the biological control of cane toads.

Analysis of wildfire extinguishment can help to identify the relative contribution of weather and management to the prevention of fire spread. Here we examine the role of weather, previous fire scars and other fuel interruptions at stopping the spread of nine large (mean 90 000 ha) late dry season fires in Arnhem Land, in the tropical savannas of northern Australia. Daily spread was mapped using Moderate-resolution Imaging Spectroradiometer (MODIS) satellite imagery with a resolution of 250 m. We sampled points along the boundary of the fires and 1 km inside the boundary and compared conditions between the two sets. Using a combination of binomial regression and regression tree analysis, we found that recent burn scars (from the same year) were very effective at stopping fires. Where there was any recent burning within 500 m of a point, there was a 92% likelihood that it was a boundary. Interruptions such as roads, rivers and topography had small but significant effects. Vegetation type and vegetation greenness also had minor effects. Weather had a small effect via wind speed. This minor role of weather was reinforced by the fact that on most days the fires were both spreading and stopping at different parts of their perimeter. In these savannas, the weather in the late dry season is relatively invariant and is probably always conducive to some degree of fire spread. Here, interruptions to the fuel are critical to stopping fires. Nevertheless, for approximately half of boundary cases, the cause of stopping was not clear. This is probably due to the coarse scale of the analysis that does not reflect fine patterns of fuel arrangements.

It is often hypothesized that two species competing for the same resource cannot stably coexist unless they partition their resources in space and time. More recently stable isotope analyses have complemented traditional, observation-based niche research by conceptualizing many of the characteristics of communities, for example, trophic niche width and the partitioning of resources. Here we quantify resource partitioning of sympatric small mammal species in an African ecosystem by analysing stable isotope ratios of hair collected from a South African forest-grassland vegetation mosaic, and combine this with known spatial and temporal behavioural data to interpret community competition and resource partitioning. We observe niche separation to different degrees across the entire community, with different species displaying either unique isotopic dietary preferences, or partitioning resources in space and/or time. δ¹³C values were more enriched in species that inhabited afromontane grassland compared with those that inhabited afromontane forest, a reflection of the dominant vegetation in each habitat. Contrary to expectations, arboreal rodents occupied higher trophic positions than terrestrial rodents and approaching δ¹⁵N values similar to insectivorous shrews, suggesting that arboreal rodents feed on items such as arthropods enriched in ¹⁵N. While grassland species display phenotypic plasticity in terms of dietary preferences, small mammals that occurred in forests display narrow niche preferences, suggesting these species may be particularly sensitive to habitat modifications. Our results illustrate that the use of stable isotopes can be used in conjunction with spatial and temporal behavioural knowledge to elucidate resource partitioning in small African mammal communities.

Beta diversity is defined as the variation in species composition among sites within a region of interest. This variation can be explained by different metacommunity paradigms, which are not mutually exclusive. While species sorting emphasizes the role of habitat features in affecting species composition, the neutral model suggests that constraints on dispersal are key assembly factors. We assessed the role of environmental features and spatial descriptors at multiple scales, in affecting avian beta diversity across a gradient of coastal habitats in southern Brazil. During the winter 2008 and summer 2009, we counted birds in 57 plots on a sandy beach and in coastal dunes and coastal grasslands (19 plots per habitat). We measured the structure of the herbaceous vegetation, the number of individual cactuses and shrubs, and the percentages of sand and water cover on each plot. We generated spatial filters by means of principal coordinates of neighbour matrices. We used variation partitioning based on redundancy analysis to decompose the fraction of beta diversity explained by environmental features and spatial descriptors at the scale of the entire gradient and within each habitat type. In both seasons, environmental variables explained 33% of beta diversity across the entire gradient. A third of this amount could also be explained by space, representing the fraction of species and environmental variables that were spatially structured. Pure environmental processes explained about 22% of beta diversity. Pure spatial control was weak at this larger scale. The opposite pattern was found within each habitat type, as there was no environmental control and neutral processes became dominant at this smaller scale. Our study thus presents a case where the strong environmental gradient filters out different species at the largest scale, whereas stochastic processes and spatial autocorrelation increase with loss of environmental heterogeneity within habitat types.

Driven by the mobility of organisms and novel habitats created by anthropogenic changes of landscape structure and climate, range expansion can modify the functioning of recipient ecosystems by altering ecosystem processes such as intra- and cross-trophic biotic interactions. We explain the spatial and temporal dynamics of the recent range expansion of painted reed frogs (Hyperolius marmoratus Rapp) in the Western Cape Province of South Africa. We identify the geographical and temporal origin of expansion, quantify extent of occurrence, internal range structure and habitat characteristics of occupied sites. The painted reed frog was introduced into its novel range during 1997 or early 1998, and is now widespread. Highly variable annual spread rates suggest both diffusion-based and human-mediated jump dispersal as drivers of the range expansion. Spatial structure is evident at the scale of the entire novel range, with two distinct populations separated by at least 100 km of unoccupied terrain. Models show that occupancy is limited by summer aridity, low winter temperatures and the absence of fringing vegetation around water bodies. The range structure and the presence of breeding populations in 26% of water bodies surveyed imply that there are further opportunities for range expansion across the network of artificial water bodies available. We infer that, facilitated by human-mediated jump dispersal and the dense distribution of perennial farm dams, painted reed frogs have colonized the winter rainfall region of south-western South Africa and fit the description of ‘urban exploiters’. Unspecialized habitat requirements, rapid spread and high local population sizes further suggest that they could compete with co-occurring endemic frogs and hamper the conservation of these range-restricted amphibians.

New knowledge about the responses of species to fire is needed to plan for biodiversity conservation in the face of changing fire regimes. However, the knowledge that is acquired may be influenced by the sampling method and the taxonomic resolution of a study. To investigate these potential sampling biases, we examined invertebrate responses to time since fire in mallee woodlands of southern Australia. Using a large-scale replicated study system, we sampled over 60 000 invertebrates with large pitfall traps, wet pitfall traps and sweep nets, and undertook analyses at morphospecies and order level. Large pitfalls and sweep nets detected several strong fire effects, whereas wet pitfall traps detected few effects. Invertebrate abundance in sweep nets was highest shortly after fire because of grasshopper outbreaks. Several additional morphospecies showed strong preferences for different stages in the post-fire succession. In contrast with morphospecies effects, analyses at order level either failed to detect fire effects or were driven by the most abundant species. For fire research to produce credible results with the potential to guide management, it must use a range of sampling techniques and undertake analyses at (morpho)species level. Homogeneous fire management, such as fire suppression in fragmented landscapes or widespread frequent burning for asset protection, is likely to cause declines in fire-affected invertebrates.

A key task in ecology is to understand the drivers of animal distributions. In arid and semi-arid environments, this is challenging because animal populations show considerable spatial and temporal variation. An effective approach in such systems is to examine both broad-scale and long-term data. We used this approach to investigate the distribution of small mammal species in semi-arid ‘mallee’ vegetation in south-eastern Australia. First, we examined broad-scale data collected at 280 sites across the Murray Mallee region. We used generalized additive mixed models (GAMMs) to examine four hypotheses concerning factors that influence the distribution of individual mammal species at this scale: vegetation structure, floristic diversity, topography and recent rainfall. Second, we used long-term data from a single conservation reserve (surveyed from 1997 to 2012) to examine small mammal responses to rainfall over a period spanning a broad range of climatic conditions, including record high rainfall in 2011. Small mammal distributions were strongly associated with vegetation structure and rainfall patterns, but the relative importance of these drivers was species-specific. The distribution of the mallee ningaui Ningaui yvonneae, for example, was largely determined by the cover of hummock grass; whereas the occurrence of the western pygmy possum Cercartetus concinnus was most strongly associated with above-average rainfall. Further, the combination of both broad-scale and long-term data provided valuable insights. Bolam's mouse Pseudomys bolami was uncommon during the broad-scale survey, but long-term surveys showed that it responds positively to above-average rainfall. Conceptual models developed for small mammals in temperate and central arid Australia, respectively, were not, on their own, adequate to account for the distributional patterns of species in this semi-arid ecosystem. Species-specific variation in the relative importance of different drivers was more effectively explained by qualitative differences in life-history attributes among species.

Metabolomics may be defined as the analysis of thousands of naturally occurring small molecules (metabolites) such as sugars, organic acids, amino acids and nucleotides that are the products of cellular metabolism. As such, it is essentially the study of the complete biochemical phenotype (or metabotype) of any biofluid, cell, tissue or indeed organism, at both the qualitative and quantitative level. Metabolic profiles are context dependent, and will change in response to environmental circumstances. Therefore, while the technique has primarily been used in biomedical research to date, it is also applicable to ecological investigations and shows great promise in measuring the impact of factors such as climate change, disease, food restriction, infection and parasite load. In this review we detail the history and background of metabolomics and discuss examples of previous and potential future metabolic studies and applications in ecological science.

Reintroductions are conducted to re-establish a self-sustaining population of a species and contribute to ecosystem restoration. The brown treecreeper (Climacteris picumnus) reintroduction into two nature reserves in the Australian Capital Territory in south-eastern Australia failed to meet its predetermined criteria for success. This occurred despite prior habitat restoration within the reserves where reintroduction occurred. Low survival of reintroduced brown treecreepers, particularly due to predation by native predators, has previously been highlighted as a key factor in the failure of the programme. We compared bird behaviour and habitat characteristics between the reintroduction reserves and the sites where brown treecreepers were sourced (which support stable brown treecreeper populations). We did not identify an indication of significantly higher predation pressure in the reintroduction reserves in comparison with the source sites. However, our results revealed that reintroduced individuals may be more vulnerable to predation because of an increased flight time to reach a refuge area. This was a result of a significantly lower number of refuge areas in logs and trees and a higher number of shrubs (which may obstruct escape paths and hinder detection of predators) in the reintroduction reserves compared with the source sites. We identified a lower ground foraging habitat quality in the reintroduction reserves because of lower numbers of ant mounds and lower areas of forageable ground. However, brown treecreepers were able to disperse extensively throughout the reserves and settle in areas with generally higher-quality foraging habitat. Therefore, the negative effect of low ground foraging habitat quality would have been most pronounced immediately after release. This study emphasizes the inherent complexities of species reintroductions and ecosystem restoration. Despite experimental restoration activities within the reintroduction reserves, there were still deficiencies in habitat quality. We emphasize that further habitat restoration is required within these reserves to achieve more complete restoration.

Understanding how plant communities respond to plant invasions is important both for understanding community structure and for predicting future ecosystem change. In a system undergoing intense plant invasion for 25 years, we investigated patterns of community change at a regional scale. Specifically, we sought to quantify how tussock grassland plant community structure had changed and whether changes were related to increases in plant invasion. Frequency data for all vascular plants were recorded on 124, permanent transects in tussock grasslands across the lower eastern South Island of New Zealand measured three times over a period of 25 years. Multivariate analyses of species richness were used to describe spatial and temporal patterns in the vegetation. Linear mixed-effects models were used to relate temporal changes in community structure to the level and rate of invasion of three dominant invasive species in the genus Hieracium while accounting for relationships with other biotic and abiotic variables. There was a strong compositional gradient from exotic- to native-dominated plant communities that correlated with increasing elevation. Over the 25 years, small-scale species richness significantly decreased and then increased again; however, these changes differed in different plant communities. Exotic species frequency consistently increased on some transects and consistently declined on others. Species richness changes were correlated with the level of Hieracium invasion and abiotic factors, although the relationship with Hieracium changed from negative to positive over time. Compositional changes were not related to measured predictors. Our results suggest that observed broad-scale fluctuations in species richness and community composition dynamics were not driven by Hieracium invasion. Given the relatively minor changes in community composition over time, we conclude that there is no evidence for widespread degradation of these grasslands over the last 25 years. However, because of continuing weed invasion, particularly at lower elevations, impacts may emerge in the longer term.

Habitat fragmentation can have a range of negative demographic and genetic impacts on disturbed populations. Dispersal barriers can be created, reducing gene flow and increasing population differentiation and inbreeding in isolated habitat remnants. Aggregated retention is a form of forestry that retains patches of forests as isolated island or connected edge patches, with the aim of ‘lifeboating’ species and processes, retaining structural features and improving connectivity. Swamp rats (Rattus lutreolus) are a cover-dependent species that are sensitive to habitat removal. We examined the effects of aggregated retention forestry and forestry roads in native wet Eucalyptus forests on swamp rat gene flow and population genetic structure. We characterized neighbourhood size in unlogged forest to provide a natural state for comparison, and examined population structure at a range of spatial scales, which provided context for our findings. Tests of pairwise relatedness indicated significant differentiation between island and edge populations in aggregated retention sites, and across roads in unlogged sites. Spatial autocorrelation suggested a neighbourhood size of 42–55 m and revealed male-biased dispersal. We found no genetic isolation by geographical distance at larger (>2.3 km) scales and populations were all significantly differentiated. Our results suggest that removal of mature forest creates barriers for swamp rat dispersal. In particular, roads may have long-term impacts, while harvesting of native forests is likely to create only short-term dispersal barriers at the local scale, depending on the rate of regeneration.

Fires are one of the main causes of forest loss in the tropics. Understanding the dynamic edge effects is critical for managing fires and protecting forests. We measured and analysed trends in microclimatic conditions (air temperature, relative humidity and vapour pressure deficit) over 7 months along three transects extending from core savanna areas to core forest areas. We tested two hypotheses: (i) that the forest edge is subject to microclimatic edge effects, and (ii) that the depth of these edge effects increases during dry periods. Sharp changes in each microclimatic variable were consistently observed between savanna and forest throughout the study period. Microclimatic transitions took place within 5 m outside the forest boundary. Drought levels increased homogenously throughout the forest and were not disproportionately severe in the vicinity of the forest edge. We suggest that these results were related to the fact that the studied period was abnormally humid due to a La Niña episode, and that under such conditions the vulnerability of the forest edge to savanna fires is relatively low. Relatively wet conditions in the savanna close to the forest edge may promote forest expansion by limiting fire spread. Prescribed fires during humid years could reduce fuel loads in savanna without affecting the forest edge, which would prevent fires during the dry years associated with El Niño episodes from having severe impacts.

Pseudofactorialism is defined as ‘the invalid statistical analysis that results from the misidentification of two or more response variables as representing different levels of an experimental variable or treatment factor. Most often the invalid analysis consists of use of an (n + 1)-way anova in a situation where two or more n-way anovas would be the appropriate approach’. I and my students examined a total of 1362 papers published from the 1960s to 2009 reporting manipulative experiments, primarily in the field of ecology. The error was present in 7% of these, including 9% of 80 experimental papers examined in 2009 issues of Ecology and the Journal of Animal Ecology. Key features of 60 cases of pseudofactorialism are tabulated as a basis for discussion of the varied ways and circumstances in which the error can occur. As co-authors, colleagues, editors and anonymous referees and editors who approved them for publication, a total of 459 persons other than the senior authors shared responsibility for these 60 papers. Pseudofactorialism may sometimes be motivated by a desire to test whether different response variables respond in the same way to treatment factors. Proper procedures for doing that are briefly reviewed. A major cause of pseudofactorialism is the widespread failure in statistics texts, primary literature and documentation for statistics software packages to distinguish the three major components of experimental design – treatment structure, design structure, response structure – and clearly define key terms such as experimental unit, evaluation unit, split unit, factorial and repeated measures. A quick way to check for the possible presence of the pseudofactorialism is to determine whether the number of valid experimental units in a study is smaller than (i) the error degrees of freedom in a multi-way anova; or (ii) the total number of tallies (N) in a multi-way contingency table. Such situations also can indicate the commission of pseudoreplication, however.

Here, we studied the ecological significance of Saprolegnia infections (‘saprolegniasis’) on the survival and development of two populations of the endemic Patagonian anuran Pleurodema thaul (Anura, Leiuperidae). We found that four different Saprolegnia species infected eggs and embryos of P. thaul, indicating that the infection by these ‘zoosporic fungi’ was different in each anuran population and among different cohorts. Late anuran cohorts generally showed a higher incidence of infection than early cohorts, but we observed no clear overall pattern between populations. In addition, in laboratory experiments, we determined that some of the Saprolegnia species induce early hatching, and that hatching timing was variable between populations. In summary, we found that early breeding (by underlying priority effects) could improve the survival of the earliest cohorts of P. thaul by allowing them to survive the stress imposed by epidemic events of Saprolegnia.

The dynamics of population niches result from the variation in resource use within individuals and also from the variation between individuals. The prevalence of one mechanism or the other leads to competing hypotheses about the major mechanisms underlying the empirical observations of the contraction/expansion dynamics of the trophic niche in natural populations. In this study, we investigated how within- and between-individual variation in resource use shapes the food niche dynamics of the woolly mouse opossum, Marmosa paraguayana (Didelphimorphia: Didelphidae), in a remnant of the highly seasonal Cerrado in south-eastern Brazil. To do so, we analysed the faecal samples of live-trapped individuals to determine their diets within the wet and dry seasons. In addition to a seasonal shift in the composition of the diet, the population trophic niche was significantly wider during the dry season than the wet season. This expansion resulted from larger between-individual variation in the dry season that was not related to sex preferences, whereas the individual niche widths did not significantly increase from the wet to the dry seasons. Our findings add to the growing list of animal populations that show individual-level variation in resource use. Furthermore, these results represent a pattern of individual-level response to seasonal changes that is different from patterns reported for other organisms. We suggest that a pathway to build more realistic foraging models and produce more accurate predictions on population and community dynamics is to consider between-individual variation and short-term niche dynamics.

There is a growing body of evidence suggesting that widespread (i.e. common) rather than geographically restricted species (i.e. rare) shape the overall distribution patterns of species richness. This is a non-intuitive fact, given that local and regional assemblages are normally composed by numerous rare species and few common ones. We evaluated here the primacy of common species in a biogeographic transition zone, where rarity has frequently a higher incidence. We analysed the geographical variability of trees and shrubs in Uruguay, located in a transitional zone between prairie and forest biomes, to assess the relative contribution of rare and common species to the generation of richness patterns. The distribution of 301 species of the native woody assemblage of Uruguay was mapped over the national grid system (302 quadrants of approximately 22 × 30 km), using published data and herbarium records. The overall assemblage was segregated into four subassemblages in function of species distribution (quartiles). Species richness in the four quartiles was positively correlated with overall richness, but common species (quartile 3) showed the highest level of correlation. Then, we ranked species from the most widespread to the most restricted (common-to-rare) and from the most restricted to the most widespread (rare-to-common). Along each stage of the sequences we obtained a series of species richness patterns for increasing numbers of species. Correlating the species richness pattern for each subassemblage of both sequences with that of the full assemblage, we also found higher correlations in the common-to-rare sequence. We conclude the Uruguayan woody plants assemblage has a very large number of rare species as expected for a transitional biogeographical zone, but it was the common species that contributed most to the overall pattern of species richness. We propose the low contribution of rare species is explained by the most interspecific variability in ecological determinants within the assemblage of rare species. Therefore the spatial covariance among rare species is low, and so is the relationship with overall species richness.

The persistence of treeless grasslands and sedgelands within a matrix of eucalypt and rainforest vegetation in the montane plateaux of northern Tasmania has long puzzled ecologists. Historical sources suggest that Tasmanian Aborigines were burning these treeless patches and models seeking to explain their maintenance generally include fire, soil properties and Aboriginal landscape burning. We aimed to provide a new historical perspective of the dynamics of the vegetation mosaics of Surrey Hills and Paradise Plains in north-west and north-east Tasmania, respectively, and used vegetation surveys and soil sampling to explore the role of vegetation and soils in these dynamics. Sequences of historical maps (1832 and 1903) and aerial photography showed that many treeless patches have persisted in the landscape since European settlement and that forests have rapidly expanded into the treeless patches since the early 1950s. Stand structure and floristic data described an expanding forest dominated by Leptospermum, which is consistent with vegetation succession models for the region. Soils under expanding forest boundaries did not have higher soil nitrogen or phosphorus than those under stable boundaries, signalling a lack of edaphic limitation to forest expansion. The magnitude of forest expansion at Paradise Plains (granite), Surrey Hills (basalt) and south-west Tasmania (quartzite) appears to follow a nutrient availability gradient and this hypothesis is backed by differences in soil phosphorus capital between the three systems. Given that existing vegetation boundaries in northern Tasmania do not coincide with soil nutrient gradients, we suggest that treeless vegetation was maintained by Aboriginal landscape burning and that the recent contraction of treeless vegetation is related to the breakdown of these fire regimes following European settlement. The observed rates of forest expansion could result in a substantial loss of these grasslands if sustained through this century and therefore our work supports the continuation of prescribed burning to maintain this high conservation value ecosystem.

Habitat corridors that facilitate functional connectivity are a fundamental component of wildlife conservation in fragmented landscapes. However, the landscape matrix separating suitable habitat is not uniformly impermeable to movement and management to increase matrix permeability could be an alternative means to maintain connectivity. Gliding mammals are particularly sensitive to fragmentation because their movements are constrained by glide distance thresholds. Populations of gliders in cities are at risk of being isolated by increasing habitat loss and urban development, yet little is known about how the urban matrix affects glider movement. Here we investigate how the level of urbanization and tree cover in the matrix influence matrix permeability to sugar gliders (Petaurus breviceps) within suburban forest reserves. Twenty-two sugar gliders were radio-tracked over winter and summer at four reserves. Boundary crossing behaviour was measured as the number of times each glider crossed into the matrix, and matrix permeability was determined as the maximum distance travelled by gliders into the matrix. The majority of gliders (81%) were located in the matrix at least once, and rates of boundary crossing were consistent across urbanization and tree cover levels. Matrix permeability was negatively affected by matrix urbanization, but not by matrix tree cover, and no interaction effects were found. Although distances travelled by gliders into the matrix did not exceed 180 m, they were comparable with typical movement distances by gliders in reserves. Our results demonstrate that the urban matrix can provide suitable habitat for gliding mammals to move and forage, but that increased urbanization may inhibit glider use of the matrix irrespective of tree cover. This finding has implications for conservation planning and suggests that structurally connected areas may not be used if movement behaviour is inhibited. Conversely, management of matrix permeability could be used to maintain connectivity without needing to construct physical corridors.

The Capricorn yellow chat Epthianura crocea macgregori (Aves: Meliphagidae) occurs in the seasonal wet-dry tropics. This region, although coastal, is typified by highly variable annual rainfall. The Capricorn yellow chat breeds in wetlands, predominantly in the summer–autumn period, but has the capacity to breed in response to out-of-season rainfall events, consistent with an opportunistically breeding species. Most studies of breeding cues in passerines have been on species centred on temperate climates with predictable rainfall season, arid biomes with a highly variable rainfall quantity and season, and the relatively non-seasonal wet tropics. This study was focused on a species that occurs in an intermediate situation with a highly variable but summer dominant rainfall season. It aimed to identify which proximal cues are used by birds in such environments to prepare for breeding. Monthly observations at a breeding ground over a 45-month period were regressed against environmental and climatic variables. There was a significant positive relationship of chat abundance with average minimum monthly air temperature and the extent of inundation. Invertebrate food availability was also sampled. Cross-correlation with prior monthly rainfall showed that abundance of insects (Diptera, Hemiptera and Lepidoptera) and semi-aquatic invertebrates peaked 1–2 months following large rainfall events, coinciding with peaks in presence of dependent young of Capricorn yellow chats. Thus, the Capricorn yellow chat matches the model for arid-adapted birds in which seasonal cues (e.g. increasing day-length or temperature) in spring lead to breeding preparedness, but breeding only occurs in response to proximal factors such as rainfall. However, the Capricorn yellow chat differs in that breeding is delayed until rainfall is sufficient to inundate its wetland habitat and stimulate the production of food resources associated with the low vegetation and muddy margins of the temporarily flooded pools and channels; suggesting that inundation may be the most important breeding cue.

The spatial distribution and density of scientists can have important implications for key aspects of scientific processes, such as innovation, networking, rates of knowledge exchange and success in large competitive grants. In this paper, we examine the research output of different research organizations and universities in Australia, with the aim of identifying hotspots of ecological research and how these hotspots have changed over the last 20 years. We used publications from 10 reputable peer-reviewed international journals as a measure of research output. We identified a number of ecology hotspot clusters. Some clusters have developed significantly over the last 20 years, while others have declined in output over time. The University of Sydney, University of Queensland, James Cook University and Melbourne University had the largest output levels among universities. Results also showed large increases in output over the last 5-year period (2006–2010), possibly because of the impending introduction of the Excellence in Research for Australia.

The imposition of the stresses of climate change (higher temperatures and in many regions lower rainfall) on existing stressors, such as habitat loss and degradation, will increase pressures on native fauna already experiencing declines. We focused on assessing how the ‘Big Dry’ (severe drought, 1997–2010) in south-eastern Australia affected populations of a small marsupial carnivore, the yellow-footed antechinus (Antechinus flavipes), in box-ironbark forests, which suffer a range of anthropogenic disturbances. Trapping of the mammal was conducted on 136 (0.25 ha) sites in two box-ironbark forests in 2004, 2005 and 2011 (46 or 64 sites per year). Capture rates of all distinct individuals, males and second-year females with suckled teats, and the number of suckled teats were positively associated with rainfall in the previous September (time of lactation and deposition of young in nests). Despite differences between forests in capture rates of all individuals, the positive effect of rainfall was evident in both forests. Populations in one forest, Chiltern, were substantially larger than other locations surveyed in 2004 and 2005, yet crashed to small numbers in 2011. This crash was most likely due to low rainfall in the preceding years including the lowest recorded annual rainfall (2006), below-average annual rainfall (2007, 2008 and 2009) and well-below-average rainfall in September (2006, 2007 and 2008). The predicted drying and warming climate in south-eastern Australia and habitat loss and degradation pose a threat to the viability of the yellow-footed antechinus in box-ironbark forests. An integrated approach to small-mammal management is necessary given that the region may be facing additional losses, especially during droughts, to those already experienced since the early 1800s. Our work emphasizes the need to identify specific effects of stressors on vital demographic characteristics of species.

Niche theory predicts that few closely related species can co-occur because such species tend to be ecologically similar and niche differentiation is required to avoid competitive exclusion. We analyse the co-occurrence of a remarkable 10–15 species of the ant genus Monomorium occurring within single 10 × 10 m plots in a tropical savanna of northern Australia. Most of the species are undescribed, so we use genetic analysis to validate our species demarcations. We document nest dispersion patterns, and investigate differentiation in the three primary niche dimensions: space, time and food. We also examine species differences in competitive abilities, by describing rates of foraging activity, foraging ranges, worker aggression, and levels of behavioural dominance. Analyses of nest and forager distributions showed very limited evidence of spatial segregation within plots. The great majority of species foraged either exclusively or primarily during daylight hours. Body size and isotopic analyses indicated very limited dietary differentiation. Such limited niche partitioning occurred despite the species differing markedly in their competitive abilities as measured by rates of resource discovery, recruitment and monopolization. Our findings defy the traditional assumption that multiple closely related and ecologically similar species of highly interactive taxa cannot co-occur. It seems very likely that species coexistence in our study system is determined to a very large degree by stochastic processes relating to dispersal and establishment, as predicted by neutral theory. However, neutral theory assumes competitive equivalence, whereas we found very marked differences in the competitive abilities of our co-occurring species. We suggest that competitive exclusion is prevented by the modular nature of ant colonies, with competition limiting colony performance but not preventing occurrence. We conclude that other factors that allow species persistence, and not just competitive equivalence, can allow dispersal and establishment processes to drive species coexistence.

In the last two decades, the relationship between diversity and stability/ecosystem functioning has been widely discussed and has become a central issue in ecology. Here, we assessed the relationship between wetland plant diversity and community resilience after a disturbance. Our study area was located in the Upper Paraná River floodplain (Brazil). An experiment was carried out in situ (18 1 m × 1 m plots with richness varying from 1 to 18 species). In each plot, we recorded the number of species, total per cent vegetation cover and per cent age cover of each species. The above-ground biomass of wetland plants was removed, simulating a disturbance by animal trampling or an extreme flood. The recovery of vegetation was monitored over 3 months. According to a linear regression, the recovery of wetland plants was positively correlated with diversity. Comparisons with plots containing monocultures of one of the dominant species (Polygonum stelligerum) suggested that this species did not overyield in mixed cultures. Thus, our experiments indicate that the higher resilience in richer plots after a disturbance is mainly due to the fact that species have different resource use requirements (complementarity effect) and not due to the presence of a single, more productive species. Our experiment carried out in a more real condition (in situ) showed that biodiversity is important to wetland functioning and stability, paralleling the results obtained in laboratory and mesocosms experiments. These results also suggest that the loss of plant diversity in our study area could compromise community recovery following strong disturbances.

Heavy metal pollution has likely played an important role in global biodiversity decline, but there remains a paucity of information concerning the effects of metals on amphibian diversity. This study assessed anuran species richness and distribution in relation to sediment metal content and water chemistry in wetlands located along the Merri Creek corridor in Victoria, south-eastern Australia. Anurans were present in 60% (21/35) of study sites, with a total of six species detected: the eastern common froglet (Crinia signifera), the eastern sign-bearing froglet (Crinia parinsignifera), the southern brown tree frog (Litoria ewingii), the growling grass frog (Litoria raniformis), the eastern banjo frog (Limnodynastes dumerilii) and the spotted marsh frog (Limnodynastes tasmaniensis). Mean species richness was 1.77 ± 0.32 per site, and species richness ranged from zero to six species per site. Across sites, species richness correlated negatively with sediment concentrations of six heavy metals: copper, nickel, lead, zinc, cadmium and mercury. Species richness also correlated negatively with wetland water electrical conductivity (a proxy for salinity) and concentrations of orthophosphate. Distributions of the three most commonly observed frog species (C. signifera, L. tasmaniensis and L. ewingii) were significantly negatively associated with the total level of metal contamination at individual sites. The study is the first to provide evidence for an association between metal contamination and anuran species richness and distribution in the southern hemisphere, adding to a small but growing body of evidence that heavy metal pollution has contributed to global amphibian decline.

Impacts of large herbivores (>5 kg) on woody plants in African savannas are potentially most severe among plants shorter than 1.6 m. It is well established that severe browsing leads to longer shoots, yet prevents saplings from recruiting into adult size-classes in African savannas. Increased shoot length, indicating faster shoot growth, is often associated with reduced concentrations of tannins and increased nutrient concentrations, suggesting carbon limitation. We hypothesized that, on average, large herbivores suppress stem height or circumference, but increase shoot length. We also hypothesized that if there were concomitant positive effects on nutrients, or negative effects on tannin concentrations, they would be greatest early in the wet season. We sampled saplings of four deciduous woody species (Acacia grandicornuta, Dichrostachys cinerea, Combretum apiculatum and Grewia flavescens) at different stages of the wet season in a large-scale, long-term herbivore exclusion experiment in Kruger National Park, South Africa. Plant height, shoot length and stem circumference were generally not adversely affected by large herbivores, suggesting C limitation is rarely present among deciduous saplings in semi-arid African savannas, allowing them to tolerate browsing. Time since first rainfall emerged as a predominant factor consistently affecting nutrient and tannin concentrations, rather than large herbivores. Nitrogen and phosphorus generally decreased (by 20–50%), while condensed tannin concentration increased (150–350%) during the wet season, except for one species. We postulate that A. grandicornuta is less prone than other species to accumulating tannins during the wet season because of high investment of C in spines. Although nutrient and tannin concentrations were generally not affected by large herbivores, species-specific responses were evident very early in the wet season, which is when herbivore populations are most likely to be affected by differential forage quality among plants.

Breeding aggregations are a reproductive strategy to increase mate finding opportunity. However, because aggregations skew the distribution of mature animals through conspecific attraction, rather than resource availability, the distribution of breeding sites may be reduced, so that not all suitable breeding sites are used. To examine the relationship between landscape and reproductive strategies of a threatened frog, Litoria aurea, we studied its distribution at Sydney Olympic Park over two breeding seasons. We aimed to: (i) determine the distribution and predictors of breeding ponds; and (ii) assess the significance of dispersal in the juvenile age-class. We found that the distribution of the calling males was highly skewed and occurred in large, well-connected ponds. Despite this, breeding ponds were not aggregated; pond size was the single factor explaining the distribution of breeding ponds. Juvenile frogs dispersed from breeding ponds and were not associated with a specific pond characteristic. Less breeding occurred in the second season during which fewer ponds were used for breeding including many different ponds from the previous year. These changes suggest that breeding effort and breeding pond choice are dynamic and therefore knowledge of the factors that drive breeding events will be a powerful tool in managing species, particularly in light of changing climatic regimes.

Invasive soil-borne pathogens are a major threat to forest ecosystems worldwide. The newly discovered soil pathogen, Phytophthora ‘taxon Agathis’ (PTA), is a serious threat to endemic kauri (Agathis australis: Araucariaceae) in New Zealand. This study examined the potential for feral pigs to act as vectors of PTA. We investigated whether snouts and trotters of feral pigs carry soil contaminated with PTA, and using these results determined the probability that feral pigs act as a vector. We screened the soil on trotters and snouts from 457 pigs for PTA using various baiting techniques and molecular testing. This study detected 19 species of plant pathogens in the soil on pig trotters and snouts, including a different Phytophthora species (Phytophthora cinnamomi). However, no PTA was isolated from the samples. A positive control experiment showed a test sensitivity of 0–3% for the baiting methods and the data obtained were used in a Bayesian probability modelling approach. This showed a posterior probability of 35–90% (dependent on test sensitivity scores and design prevalence) that pigs do vector PTA and estimated that a sample size of over 1000 trotters would be required to prove a negative result. We conclude that feral pigs cannot be ruled out as a vector of soil-based plant pathogens and that there is still a high probability that feral pigs do vector PTA, despite our negative results. We also highlight the need to develop a more sensitive test for PTA in small soil samples associated with pigs due to unreliable detection rates using the current method.

New technologies for quantifying animal locations enable us to document habitat-selection patterns of cryptic taxa in extraordinary detail. Northern bluetongues (Tiliqua scincoides intermedia) and centralian bluetongues (Tiliqua multifasciata) are large heavy-bodied scincid lizards that are broadly sympatric in the wet–dry tropics of north-western Australia. We used data from GPS-based radiotelemetry (n = 49 lizards, tracked for 2–121 days, total n = 61 640 locations) to examine the size, internal structure and overlap of lizard home ranges. Despite substantial habitat differences at our two study sites (semi-arid and relatively pristine habitat at Keep River National Park, Northern Territory, vs. highly disturbed and fragmented flood plain habitat in an agricultural area near Kununurra, Western Australia), home ranges were similar between the two areas, and between the two species. Our radio-tracked lizards continued to disperse into previously unused areas throughout the duration of the study, so that the total areas used by lizards continued to increase. Based on the minimum convex polygon method, total home ranges averaged 4 ha (range 2–12 ha), but only about two-thirds of each home range was used intensively. Each home range had multiple core areas, and overlap of core as well as peripheral areas (especially with same-sex conspecifics) was high at the disturbed (Western Australia) site where lizard densities were high. The concentration of lizard activity within small core areas, often used by multiple individuals, suggests that these heavily used sites are critical to lizard conservation. However, the lizards' infrequent long-distance displacements also make them vulnerable to changes in the wider landscape mosaic. Because GPS-based radiotelemetry can quantify habitat use at finer spatial and temporal scales than earlier technologies, it can provide a robust base for management of at-risk fauna.

Terrestrial environments allow the adults of some aquatic insects to disperse between headwater streams, which may be important for maintaining population connectivity and persistence. Winged adult stages of aquatic insects are particularly sensitive to degradation of terrestrial habitat, relying on it for food, reproduction and dispersal. In this study we examined the genetic pattern of the Australian mayfly Ulmerophlebia sp. AV2, in north-eastern New South Wales, and compared the genetic diversity in forested and partially deforested sub-catchments. Our hypotheses were (i) patterns of mitochondrial DNA (mtDNA) variation in the Leptophlebiidae mayfly Ulmerophlebia sp. AV2 show a pattern of structuring that reflects low or widespread dispersal along the stream network and across catchments; and (ii) genetic diversity will be lower in partially deforested sub-catchments compared to forested sub-catchments. We found gene flow was not restricted among headwater streams within sub-catchments but was restricted at distances >15 km. Genetic diversity was high (mean haplotype diversity >0.85) in both control and harvested sub-catchments. Instead, a historical signature of population expansion was detected which is consistent with findings for other aquatic insect taxa of eastern Australia. Our results suggest that the selective harvesting management strategy, including the use of riparian buffer zones, within these sub-catchments does not appear to restrict dispersal between streams or erode diversity within streams for Ulmerophlebia sp. AV2. Selective harvesting therefore appears to have minimal impacts on terrestrial/aquatic links in the life cycle of this insect.

The ability of birds to perceive, assess and appropriately respond to the presence of relatively novel threats is important to their survival. We hypothesized that the cognitive capacity of birds will influence their ability for accurate response to novelty. We used brain volume as a surrogate for cognitive capacity and postulated that larger brained birds would moderate their responses when presented with a benign, frequently occurring stimulus, such as a person, because they would habituate more readily. We conducted phylogenetic generalized least square regression to investigate the relationship between brain volume and flight initiation distance (FID; the distance to which a bird can be approached before initiating escape behaviour), while controlling for confounding factors including body size (body mass and wing length) and migration status. We compared seven different models using combinations of these parameters using Akaike's information criterion to determine the best approximating model(s) explaining FID. The two best-supported models included only wing length and only body mass with Akaike weights of 0.396 and 0.311 respectively. No model including brain volume had an Akaike weight greater than 0.083 and brain volume was poorly correlated with FID in models after controlling for body mass. Thus, brain volume does not appear to strongly relate to bravery among these shorebirds.

Hoarding food is an important strategy of rodents in desert environments characterized by unpredictable and poor food resource availability. In the Monte Desert, Prosopis produces abundant food, unevenly in time and space, in the form of pods and seeds. Sigmodontine rodents (Graomys griseoflavus, Akodon molinae, Eligmodontia typus and Calomys musculinus) use Prosopis propagules extensively, and they could be predators or dispersers depending on how they handle and where they leave the propagules. The objectives of this study were: (1) to know what rodent species transported propagules; (2) to evaluate what hoarding pattern was used by species that transport propagules (larder and scatterhoarding); and (3) to analyse in which condition were propagules left by the rodent species, both at the food source and in caches. Our results showed that all four species transported propagules, with G. griseoflavus and E. typus being the species that carried more seeds. Our study supported the evidence that food caching is common among species and that many species both larderhoard and scatterhoard food. Graomys griseoflavus and A. molinae, the largest species, larderhoarded more than did the smaller E. typus. These results uphold the hypothesis that larger species will show greater propensity to larderhoard than smaller species. Considering the interaction between seed-hoarding patterns and plants, E. typus was the species that could most improve germination because it scatterhoarded propagules and left seeds out of pods. In contrast, G. griseoflavus could have a negative impact on plant populations because this was the species that predated more seeds and larderhoarded a high percentage of them. The smallest C. musculinus was the species that transported propagules least, and left them as seeds inside pods or pod segments mainly at the food source, which makes seeds more vulnerable to predation.

Long-term ecological studies (LTES) are critical for understanding and managing landscapes. To identify important research gaps, facilitate collaborations and communicate results, several countries have established long-term ecological research networks. A few initiatives to create such a network in Australia have been undertaken, but relatively few published data exist on the current state of LTES in Australia. In this paper, we present the results of an online survey of terrestrial LTES projects sent to academic, government and non-governmental organization-based researchers across Australia. We asked questions pertaining to the focus, scope, support and outcomes of LTES spanning 7 years or longer. Based on the information reported from 85 Australian LTES, we: (i) identify the biomes, processes and species that are under-represented in the current body of research; (ii) discuss important contributing factors to the successful development and survival of these projects; and (iii) make recommendations to help increase the productivity and influence of LTES across research, management and policy sectors.

Flower-visiting insects provide essential pollination services to many plant species. It is thus of critical importance to understand the effects of anthropogenic landscape modification on these animals. Particularly at the landscape scale, we still lack information on how flower visitors are affected by different intensities of human disturbance. In this study, we chose six representative types of forest modification across a heterogeneous South African landscape. At 36 study sites we observed insect visitation to Celtis africana flowers in two consecutive years. This generalist tree species has small unspecialized flowers which we found to be pollinated by a diverse array of insects as well as by wind. Visitation rates to flowers of C. africana differed significantly among the six forest types and between two study years. Visitation rates were enhanced in modified forests, facilitated by a high abundance of feral honeybees (Apis mellifera). Fruit set in C. africana showed significant positive associations with insect visitation and with the diversity of flower visitors, but was only weakly predicted by forest type. Our findings imply that even though forest modification can strongly alter flower visitors, pollination services for trees with unspecialized flowers may persist at a landscape scale. We advise conservation managers to maintain modified forest fragments in addition to natural forests as these may contribute to sustain pollination services in human-modified landscapes.

In arid to semi-arid grasslands and savannas, plant growth, population dynamics, and productivity are consistently and strongly limited by soil water and nutrient availability. Adaptive traits of the root systems of grasses in these ecosystems are crucial to their ability to cope with strong water and/or nutrient limitation and the increasing drought stress associated with ecosystem degradation or projected climate change. We studied 18 grass species in semi-arid savanna of the Kalahari region of Botswana to quantify interspecific variation in three important root system traits including root system architecture, rhizosheath thickness and mycorrhizal colonization. Drought-tolerant species and shorter-lived species showed greater rhizosheath thickness and fine root development but lower mycorrhizal colonization compared to later successional climax grasses and those characteristic of wetter sites. In addition, there was a significant positive correlation between root fibrousness index and rhizosheath thickness among species and a weak negative correlation between root fibrousness index and mycorrhizal colonization. These patterns suggest that an extensive fine root system and rhizosheath development may be important complementary traits of grasses coping with drought conditions, the former aiding in the acquisition of water by the grass plant and the latter aiding in water uptake and retention, and reducing water loss in the rhizosphere. Within species, both rhizosheath development and mycorrhizal colonization were significantly greater in a wet year than in a year with below-average precipitation. The observed patterns suggest that the primary benefit of rhizosheath development in African savanna grasses is improved drought tolerance and that it is a plastic trait that can be adjusted annually to changing environmental conditions. The functioning of mycorrhizal symbiosis is likely to be relatively more important in infertile savannas where nutrient limitation is higher relative to water limitation.

Large identifiable landscape units, such as ecoregions, are used to prioritize global and continental conservation efforts, particularly where biodiversity knowledge is inadequate. Setting biodiversity representation targets using coarse large-scale biogeographic boundaries, can be inefficient and under-representative. Even when using fine-scale biodiversity data, representation deficiencies can occur through misalignment of target distributions with such prioritization frameworks. While this pattern has been recognized, quantitative approaches highlighting misalignments have been lacking, particularly for assemblages of mammal species. We tested the efficacy of Australia's bioregions as a spatial prioritization framework for representing mammal species, within protected areas, in New South Wales. We produced an approach based on mammal assemblages and assessed its performance in representing mammal distributions. Substantial spatial misalignment between New South Wales's bioregions and mammal assemblages was revealed, reflecting deficiencies in the representation of more than half of identified mammal assemblages. Using a systematic approach driven by fine-scale mammalian data, we compared the efficacy of these two frameworks in securing mammalian representation within protected areas. Of the 61 species, 38 were better represented by the mammalian framework, with remaining species only marginally better represented when guided by bioregions. Overall, the rate at which mammal species were incorporated into the protected area network was higher (5.1% ± 0.6 sd) when guided by mammal assemblages. Guided by bioregions, systematic conservation planning of protected areas may be constrained in realizing its full potential in securing representation for all of Australia's biodiversity. Adapting the boundaries of prioritization frameworks by incorporating amassed information from a broad range of taxa should be of conservation significance.

Manipulating resource availability to assess the strength and effects of resource limitation on an animal population is relatively straightforward, and thus, common in the scientific literature. Resource quality, however, is rarely manipulated, as this requires a priori knowledge of a relationship between some measurable variation in the resource and individual preference and/or fitness. Recent research on nest-site selection was used to inform the design of custom-built nest-boxes for an endangered hollow-nester, the Gouldian finch (Erythrura gouldiae). By provisioning breeding populations with these ‘high quality’ artificial nest sites over 3 years, we experimentally investigated the strength and effects of nest-site limitation in this species. Breeding pairs using nest-boxes initiated nesting earlier, produced larger clutches and fledged more offspring per season than those in natural hollows. Total and mean reproductive output also increased in nest-box provisioned sites over the duration of the study. All of these effects were predominantly driven by pairs initiating clutches earlier, potentially because of the reduced intra- and interspecific competition for nest sites at optimal breeding times. Our findings suggest that reproduction in wild Gouldian finch populations may be limited by the availability of high quality nest sites in the landscape, and that nest-boxes could be used as a tool for enhancing reproduction in recovering populations. Furthermore, we conclude that resource quality is equally, if not more important than quantity when supplementing resource-limited habitats.

Cumberland Plain grassy woodland in western Sydney has been reduced to less than 12% of its pre-settlement distribution; efforts to restore it on cleared and grazed sites within its former distribution have met with mixed success. Elevated soil nitrate levels, coupled with propagule and establishment limitation, have been identified as barriers to restoration in other grasslands. Our study used a factorial combination of carbon addition, fire and native seed addition to test whether these barriers operated on a former Cumberland plain woodland site dominated by exotic perennial grasses. Replicate field plots were established in November 2004; fire plots were burnt in December 2004; carbon was then added as sugar every 3 months until September 2005; and seeds of five native grasses were added in January 2005. Carbon addition significantly reduced soil nitrate, the effect appearing in October 2005. Carbon addition and fire each reduced the total abundance of exotics; when combined, they halved the abundance of the two dominant exotic grasses. Total abundance of native species responded positively to carbon and seed addition, but significant responses to carbon were not detected for individual species. Abundance of two native grasses responded positively to fire; after treatment the native proportion of total abundance rose from 26% on controls to 44–65% on carbon and/or fire plots. Exotic species richness was decreased independently by carbon addition and fire. Native species richness was increased independently by fire and seed addition. All five native grasses established sporadically, but only on carbon and/or fire plots. The three treatments each significantly and independently affected species composition, which showed the greatest change when all three were applied. The three treatments collectively increased the proportion of natives in measures of both plant abundance and species richness. The study confirmed that elevated soil nitrate, plus propagule and recruitment limitation are barriers to restoring this grassy woodland on cleared and grazed sites.

The mainland portion of the Adelaide Geosyncline (Mount Lofty and Flinders Ranges) has been postulated as an important arid-zone climate refugium for Australia. To test the sensitivity of this putative Australian arid biome refugium to contemporary climate change, we compared Generalized Additive Modelling and MaxEnt distribution models for 20 vascular plant species. We aimed to identify shared patterns to inform priority areas for management. Models based on current climate were projected onto a hypothetical 2050 climate with a 1.5°C increase in temperature and 8% decrease in rainfall. Individual comparisons and combined outputs of logistic models for all 20 species showed range contraction to shared refugia in the Flinders Ranges and southern Mount Lofty Ranges. Modelling suggests the Flinders Ranges will experience species turnover while suitable climatic habitat will be retained in the Mount Lofty Ranges for the current suite of species. Fragmentation of the southern Mount Lofty Ranges poses management challenges for conserving species diversity with warming and drying. Although projected models must be interpreted carefully, they suggest the region will remain an important but threatened refugium for mesic species at a continental scale.

The biotic resistance theory relates invader success to species richness, and predicts that, as species richness increases, invasibility decreases. The relationship between invader success and richness, however, seems to be positive at large scales of analysis, determined by abiotic constraints, and it is to be expected that it is negative at small scales, because of biotic interactions. Moreover, the negative relationship at small scales would be stronger within species of the same functional group, because of having similar resource exploitation mechanisms. We studied the relationship between the cover of a worldwide invader of grasslands, Hieracium pilosella L., and species richness, species diversity and the cover of different growth forms at two different levels of analysis in 128 sites during the initial invasion process in the Fuegian steppe, Southern Patagonia, Argentina. At regional level, the invader was positively correlated to total (r = 0.28, P = 0.003), exotic (r = 0.273, P = 0.004), and native species richness (r = 0.210, P = 0.026), and to species diversity (r = 0.193, P = 0.041). At community level, we found only a weak negative correlation between H. pilosella and total richness (r = −0.426, P = 0.079) and diversity (r = −0.658, P = 0.063). The relationship between the invader and other species of the same growth form was positive both at regional (r = 0.484, P < 0.001) and community (r = 0.593, P = 0.012) levels. Consequently, in the period of establishment and initial expansion of this exotic species, our results support the idea that invader success is related to abiotic factors at large scales of analysis. Also, we observed a possible sign of biotic constraint at community level, although this was not related to the abundance of species of the same growth form.

We performed a comprehensive comparative study of functional traits in coexisting alien and native woody species in order to examine the strategies related to resource use and dispersion underlying alien success in mountain Chaco woodlands of central Argentina. Our approach integrated seemingly contrasting pieces of evidence in the region. We specifically assessed whether (i) the ‘functional acquisitive trend’ previously observed along a broad environmental gradient accounts for woody alien naturalization when considering a single mesic ecosystem; or (ii) more than one trait syndrome is important among alien species, which would be more in line with the context-dependent nature of biological invasions at a local scale. Fifteen vegetative and regenerative traits were measured on the most common 14 native and 11 alien woody species. We compared the attributes of (i) native and alien species and (ii) between native species and two contrasting groups of alien species identified in the previous analysis. The overall trait comparison (i) showed that, in terms of vegetative attributes, woody alien species tend to be on average more acquisitive than native species. However, (ii) two contrasting syndromes were revealed among alien species: a group of seven deciduous species with acquisitive attributes; and a group of four evergreen species showing markedly more conservative attributes than the first group. The functional attributes of ‘conservative aliens’ completely overlapped with the range observed for native species, except for an exclusive dispersal phenology and a stronger tendency to clonal spread. Acquisitive aliens, in turn, proved to be beyond the range of attributes of native species, at the acquisitive extreme, as they did in previous comparisons. Despite their importance, general trends in plant functional attributes across regions and ecosystems can sometimes obscure trends at more local scales that are nevertheless important for the understanding and management of particular systems. Our study concurs with previous general trends when looking at the overall comparison between native and alien species, but unveils contrasting functional strategies among alien species when examining their attributes more closely, even within the same ecosystem.

Autotomy, the self-amputation of limbs or appendages, is a dramatic anti-predator tactic that has repeatedly evolved in a range of invertebrate and vertebrate groups. In lizards, caudal autotomy enables the individual to break away from the predator's grasp, with the post-autotomy thrashing of the tail distracting the attacker while the lizard makes its escape. This drastic defensive strategy should be selectively advantageous when the benefit (i.e. survival) exceeds the subsequent costs associated with tail loss. Here, we highlight how the position of autotomy along the length of the tail may influence the costs and benefits of the tactic, and thus the adaptive advantage of the strategy. We argue that most studies of caudal autotomy in lizards have focused on complete tail loss and failed to consider variation in the amount of tail shed, and, therefore, our understanding of this anti-predator behaviour is more limited than previously thought. We suggest that future research should investigate how partial tail loss influences the likelihood of surviving encounters with a predator, and both the severity and duration of costs associated with caudal autotomy. Investigation of partial autotomy may also enhance our understanding of this defensive strategy in other vertebrate and invertebrate groups.

Bees are mobile organisms that seek food and nesting opportunities from a range of habitats. It is important to understand the way they move in agricultural landscapes if we are to conserve them and benefit from their activity as pollinators. We surveyed bees using directional flight interception (Malaise) traps over a 1-year period in two agricultural landscapes in south-east Queensland, Australia. We placed traps at the ecotone between crops and remnant vegetation to establish the pattern of movement between these habitats. Species richness in these landscapes (70) was high relative to that in comparable studies. Some bees were active year round, but most were caught in the period September to March. Across the whole assemblage there was a significant pattern where more species were detected leaving rather than entering remnant vegetation. The same bias was true for the number of individuals of the two most abundant species (Homalictus urbanus and Apis mellifera). Species exclusively found in crops were smaller on average (and therefore have smaller foraging range) than their non-crop counterparts. Together, these patterns indicate that while bees are abundant in crop habitat, the remnant vegetation is important as the point of origin for bee movements, and the riparian remnant in particular is richer than the dry native remnant. Compositional similarity among samples was significantly explained by landscape but also movement direction (i.e. to or from the riparian remnant) because different species showed different patterns of response. The landscape with greater native vegetation cover supported more species in and around crops than the landscape with less native vegetation.

Global climate change is a threat to ecosystems that are rich in biodiversity and endemism, such as the World Heritage-listed subtropical rainforests of central eastern Australia. Possible effects of climate change on the biota of tropical rainforests have been studied, but subtropical rainforests have received less attention. We analysed published data for an assemblage of 38 subtropical rainforest vertebrate species in four taxonomic groups to evaluate their relative vulnerability to climate change. Focusing on endemic and/or threatened species, we considered two aspects of vulnerability: (i) resistance, defined by indicators of rarity (geographical range, habitat specificity and local abundance); and (ii) resilience, defined by indicators of a species potential to recover (reproductive output, dispersal potential and climatic niche). Our analysis indicated that frogs are most vulnerable to climate change, followed by reptiles, birds, then mammals. Many species in our assemblage are regionally endemic montane rainforest specialists with high vulnerability. Monitoring of taxa in regenerating rainforest showed that many species with high resilience traits also persisted in disturbed habitat, suggesting that they have capacity to recolonize habitats after disturbance, that is climate change-induced events. These results will allow us to prioritize adaptation strategies for species most at risk. We conclude that to safeguard the most vulnerable amphibian, reptile and bird species against climate change, climatically stable habitats (cool refugia) that are currently without protection status need to be identified, restored and incorporated in the current reserve system. Our study provides evidence that montane subtropical rainforest deserves highest protection status as habitat for vulnerable taxa.

Amphibians are typically intolerant of high temperatures and dehydrating conditions, and small species are particularly susceptible to desiccation. The rockhole frog, Litoria meiriana (Hylidae), is diurnal and is often observed on rocks in the sun near streams in tropical Australia. These hot, desiccating conditions are avoided by most frog species. We measured the microclimate in the areas used by frogs and the activity, body temperatures and hydric state of free-ranging individuals of this small frog. We also used plaster models to further explore the dynamic nature of hydric state by combining estimates of water loss and water uptake with behavioural observations of activity and microhabitat selection. Both direct measures and estimates of dynamic hydric state indicated that free-ranging frogs generally maintained a hydric state above 95% of full hydration, but occasionally, particularly during the afternoon, frogs allowed their hydric state to fall as low as 85%. Body temperatures of frogs remained below the critical thermal maximum (CT_max) even when the frogs were in the sun, because this species has no cutaneous resistance to evaporative water loss and so they cool by evaporation. However, during the hotter part of the day, on dry sunny substrates, the hydric state of the frogs could fall to near lethal hydration states (approximately 70% of full hydration) within a short period (approximately 20 min). Thus, the threat of desiccation appears to be more limiting than the threat of overheating. These diurnal frogs rely on frequent bouts of rehydration to support their ability to venture onto hot, dry rocks during the day.