SEARCH

SEARCH BY CITATION

In April 2010, the annual conference of the British Ornithologists’ Union took place at the University of Leicester. The theme for this year’s conference was ‘Climate Change and Birds’ and within this context a wide spectrum of issues was covered, ranging from the direct effects of climate change on phenology and physiology through to impacts on species’ habitats and ranges as well as the possible consequences of climate change mitigation strategies on avian populations.

The conference began with a welcome address from BOU President, Alistair Dawson (CEH), followed by a keynote speech by Professor Rhys Green (University of Cambridge), which provided an overview of the effects of climate change on birds, thereby setting the scene for all the conference talks to follow (Green 2010). While considerable information is available on the impacts of changing climatic conditions on distribution, abundance and demographic patterns, the talk highlighted the importance of also considering subtle inter-specific interactions if we are to gain a comprehensive understanding of climate impacts. The uncertainties of modelling future climate impacts on populations and the dangers of making a priori assumptions when modelling were also touched upon.

The conference sessions reflected key areas of policy and research, including the direct impacts of climate change as well as the impacts of climate mitigation strategies on avian populations. The first session of the conference saw Robin Mortimer (Defra) deliver a talk that provided a policy overview on climate change and the natural environment. This was followed by a couple of sessions on the direct impacts of climate change on avian populations, which included presentations by Alastair Dawson (CEH) (Dawson & Visser 2010), Tim Sparks (Poznań University of Life Sciences, Poland) (Sparks 2010), Marcel Visser (Netherlands Institute of Ecology) (Visser et al. 2010), Dave Leech (BTO) (Leech et al. 2010) and Bernt-Erik Saether (Norwegian University of Science & Technology) (Saether 2010) on long-term monitoring efforts of European bird populations, as well as talks on climate change impacts on Arctic and Antarctic seabirds and wader communities by Sarah Wanless (CEH) (Wanless et al. 2010), Theunis Piersma (University of Groningen, The Netherlands) and Clara Péron (CNRS, France) (Péron et al. 2010).

One of the direct effects of climate change on avian populations involves changes in phenology, especially in the timing of breeding events, which may be related to temperature or photoperiodic cues in the environment. Climatic changes also impact prey species, causing a mismatch between the timing of peak prey availability and the time of greatest need for birds rearing chicks. Birds may be constrained in the degree to which they can advance breeding to compensate for advanced phenology in food abundance (Visser et al. 2010). In multi-brooded species, this may lead to the number of breeding attempts being curtailed. Asynchrony between peak prey availability and offspring demand has been reported in Great Tit Parus major and Pied Flycatcher Ficedula hypoleuca populations in the Netherlands, leading to reduced productivity and ultimately to population declines (Both & Visser 2001, Visser et al. 2006). In contrast, data were also presented at the conference from a study by the BTO that indicated that no negative temporal trend due to disjunction has as yet been identified in British populations of the same species, Pied Flycatcher populations exhibiting increased productivity in warmer springs (Leech et al. 2010). This difference between populations of the same species may be due to the differential in rate of warming in the two geographical locations (i.e. rate of warming is faster on the continent (IPCC, 2007)), to compensatory increases in productivity in warmer seasons or to insufficient data on the UK population’s food chain hindering detection of such patterns. These studies reiterate how phenological change can differ between locations, between species and between trophic levels (Harrington et al. 1999, Both & te Marvelde 2007) and can cause complexity in predicting the effects of changing climatic conditions.

Issues pertaining to scale also need to be addressed while modelling the consequences of changing environmental conditions. Apart from single species studies, several large-scale modelling efforts were also highlighted in this conference by speakers Ramona Maggini (Swiss Ornithological Institute) (Maggini et al. 2010), Savrina Carizzo (University of Cambridge) (Carizzo et al. 2010), Nathalie Doswald (UNEP-WCMC) (Doswald & Willis 2010), Steve Willis (University of Durham) (Willis & Hole 2010), Paula Harrison (University of Oxford) (Harrison et al. 2010) and James Pearce-Higgins (BTO) (Pearce-Higgins 2010). These modelling efforts have covered varying spatial scales: for example at national levels such as the ClimBird project, modelling altitudinal shifts in alpine birds in Switzerland using their national bird breeding survey data (Maggini et al. 2010); and at a continental scale, such as the research on geographical range shifts in North American breeding birds (Carizzo et al. 2010) and studies on range shifts of African migrants and predictions of African IBA conditions (Doswald & Willis 2010, Willis & Hole 2010) and multi-trophic level climate envelope models like MACIS & RUBICODE that incorporate information on bird populations within the wider context of climate change adaptation and mitigation impacts on ecosystem services and biodiversity (Harrison et al. 2010). However, comprehensive good quality data over extended time periods are required for more of these large-scale modelling efforts to be successful.

The conference talks also shed light on some of the impacts that climate mitigation strategies may have on avian populations. Torgeir Nygard (NINA, Norway) spoke on the impacts of onshore wind farms on White-tailed Eagles Haliaeetus albicilla in Norway (Nygård et al. 2010) and Eileen Rees (WWT) on offshore wind farm impacts on Whopper Swans Cygnus cygnus (Griffin et al. 2010). Martin Perrow (ECON) highlighted wind farm impacts on migratory species such as gulls, skuas, gannets and terns (Perrow et al. 2010). Niall Burton (BTO) explained the potential impact of proposed tidal power production in the Severn estuary on the breeding colonies of waders (Burton et al. 2010) and Graham Sinden gave an overview of life-cycle assessments and renewable energy (Sinden 2010). While much focus is on the negative impacts of climate mitigation strategies on bird populations, there may be management practices with beneficial effects. For instance, Rob Fuller (BTO) provided evidence that wood fuel management strategies like coppicing and thinning potentially increase habitat for birds that depend on complex low foliage (Fuller & Rothery 2010) and Benedict Gove (RSPB) indicated that bioenergy in the form of biomass crops on short rotation coppice and forestry and Miscanthus appear to support a higher abundance and diversity of species than arable or improved grassland, although compared with natural habitats these are still species-poor (Gove & Bradbury 2010). It must be noted, however, that further data are required to quantify both the negative and the positive impacts at varying spatial scales.

While the impact of wind farms on bird populations in terms of collision risks continues to be a focal point of several studies (Langston 2010), a talk by Professor Graham Martin (University of Birmingham) raised a very interesting point centred on whether collisions were a visual or a perceptual problem for birds. While acuity in birds is high, only a small proportion of the visual field (< 2%) is devoted to forward vision (Martin 2010). Furthermore, birds may be giving attention to visual information about what lies around them with only minimal attention to what lies ahead. Thus reducing collisions may require more than making potential collision objects more conspicuous. This talk highlighted the danger of research from an anthropocentric view which could lead to obviously erroneous conclusions in terms of cause, effect and solutions to perceived problems.

Challenges for future research

  1. Top of page
  2. Challenges for future research
  3. References

The final two talks of the conference were delivered by Graham Tucker (Institute for European Environmental Policy), who spoke on the policy measures for facilitating biodiversity adaptation to climate change (Tucker 2010), and Humphrey Crick (Natural England), who spoke on the challenges facing climate change adaptation for UK bird populations (Crick & Bradbury 2010). This was followed by a general discussion in which one of the key questions raised was whether the current understanding of risks to species was adequate. Research on climatic trends indicates that there is likely to be an increase in climatic extremes or ‘global weirding’, as some scientists have termed the phenomenon. To understand and accurately predict climate change impacts on species, the underlying modelling assumptions that populations require an unchanging climate niche need to be verified. Moreover, the levels of uncertainty concerning projected outcomes due to the lack of stringent validation of model predictions need to be reduced, while inclusion of information on the mechanisms of population and distributional change, and on interactions between climate change and other environmental change need to be increased.

Policy and management strategies need to counteract and compensate to facilitate density-dependent dispersal patterns conducive to range expansion. It is also important to bear in mind that an anthropocentric viewpoint is not conducive to finding solutions for avian populations. Large-scale modelling efforts like those considering the response of varied taxa to climate change (for example Hickling et al. 2006) may provide a more comprehensive understanding of the scale of the impacts, and an ‘ecosystem-based paradigm’ utilizing functional diversity may be a more appropriate and flexible network in which to consider adaptation.

Articles from this conference are now available free of charge from the BOU’s Proceedings website at http://www.bouproc.net.

It was refreshing to see so many student presentations both in the oral programme and in the excellent poster presentations. The BOU now awards prizes for the best student presentations at their annual conference and these went to Savrina Carizzo of the University of Cambridge (best student oral presentation) and Luiz Mestre of South Dakota University (best student poster presentation).

A conference of this magnitude cannot be successful without an efficient group of people working behind the scenes. The excellent conference programme was put together by Rowena Langston (RSPB), Dan Chamberlain (University of Turin (formerly BTO)), Steve Willis (University of Durham), James Higgins-Pearce (BTO (formerly RSPB)), Allan Drewitt (Natural England) and Richard Bradbury (RSPB). The conference itself was managed by the BOU’s Steve Dudley and Angela Langford. They are all commended on their efforts that ensured the success of this conference.

The BOU wishes to thank the programme organizers for delivering such a strong programme, all the speakers for their contributions, and the many volunteers who helped out during the conference. The BOU is extremely grateful to the British Trust for Ornithology, Defra, the Department of Energy & Climate Change, Durham University, Natural England, the RSPB and Scottish Natural Heritage for supporting the conference and proceedings. Defra, the Department of Energy & Climate Change, Natural England, the RSPB and Scottish Natural Heritage are thanked for their financial support of Climate Change and Birds.

References

  1. Top of page
  2. Challenges for future research
  3. References