Cover image for Vol. 157 Issue 4

Edited By: Paul F. Donald (Editor in Chief)

Impact Factor: 1.921

ISI Journal Citation Reports © Ranking: 2014: 2/21 (Ornithology)

Online ISSN: 1474-919X

Editors' Choice

Highlighted articlesHighlights from the latest issue:

A packed October issue of IBIS contains 17 full papers and three Short Communications. Here are just four of the highlights.

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Here are just four of the many highlights in this issue.

White tail spots in breeding barn swallows Hirundo rustica signal body condition during winter moult
Nicola Saino, Maria Romano, Andrea Romano, Diego Rubolini, Roberto Ambrosini, Manuela Caprioli, Marco Parolini, Chiara Scandolara, Gaia Bazzi and Alessandra Costanzo

The white tail spots of Swallows are a prominent feature on flying birds, but do they serve a purpose? Nicola Saino and her colleagues at the University of Milan assess whether the size of these spots say anything about the body condition of the bird at the time the tail feathers are grown, during winter moult prior to the arrival of birds on the breeding grounds. They find that birds in better condition had larger and less rounded white spots than birds in poorer condition. Furthermore, males had more variable spot size than females. This study is the first to provide evidence that multiple features of the white markings on feathers directly reflect body condition at the time of moult and can therefore reliably signal phenotypic quality in socio-sexual communication.

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Bird movements at rotor heights measured continuously with vertical radar at a Dutch offshore wind farm
Ruben C. Fijn, Karen L. Krijgsveld, Martin J. M. Poot & Sjoerd Dirksen

One of the greatest changes to have taken place to European landscapes in recent decades has been the proliferation of wind turbines. These are known to pose a risk to birds but quantifying this has proved problematic. Using vertical radar with automated bird-tracking software, Ruben Fijn of the Bureau Waardenburg’s Department of Bird Ecology and colleagues estimate that 1.6 million birds pass through a large offshore Dutch wind farm at heights that make them vulnerable to being hit by rotors. These are mostly gulls during the day and migrating passerines at night. Numbers passing at risk heights varied across time and with wind direction. The results further our understanding of the likely impacts of offshore wind farms.

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Floater interference reflects territory quality in the Spanish Imperial Eagle Aquila adalberti: a test of a density-dependent mechanism
Miguel Ferrer, Virginia Morandini and Ian Newton

In raptor populations, there are always a number of unpaired birds that move around between established territories. These “floaters” can interfere with breeding pairs and even reduce their productivity. It may be that as the population increases, so the density of floaters increases, and productivity as a whole falls. Alternatively, it may be that floaters are able to detect differences between territories in quality and spend more time “floating” in better territories, in which case there may be a positive relationship between floaters and productivity. Miguel Ferrer and Virginia Morandini of the Estación Biológica de Doñana and Ian Newton of the Centre for Ecology & Hydrology assess which of these conditions holds in an increasing population of the threatened Spanish Imperial Eagle Aquila adalberti. They find that floaters, particularly young males, associate primarily with more productive territories, but not at levels at which productivity is affected. Therefore, perhaps counter-intuitiviely, there is a positive relationship between productivity and floater interference.

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Soil pH and organic matter content add explanatory power to Northern Lapwing Vanellus vanellus distribution models and suggest soil amendment as a conservation measure on upland farmland
Heather M. McCallum, Kirsty J. Park, Mark G. O’brien, Alessandro Gimona, Laura Poggio and Jeremy D. Wilson

The story of declining farmland bird populations and agricultural intensification is well known, yet conservationists are still seeking solutions to the problem that are both effective and cost efficient. In a fresh take on the issue, Heather McCallum of the RSPB and colleagues assess how soil type influences Lapwing distribution, finding that fitting soil type to distribution models improves model fit by 55%. Lapwings are associated with less peaty and less acidic soils. This raises the intriguing possibility that the old practice of liming may bring benefits to this species and other upland breeding waders, including the globally threatened Eurasian Curlew.

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