Over the last 30 years, European breeding birds have shifted their range by, on average, 2.4 km (1.5 miles) per year, according to a recent study. This shift, however, didn’t align with the expectations based on changing climate and land cover during that period. Researchers anticipated that solely climate-based factors should have provoked a roughly 50% faster rate of range shifts.
Data Collection and Major Influences
The study led by experts from Durham University, UK, used survey data collected as part of two Europe-wide bird distribution atlases, published 30 years apart.
The team discovered that local colonization and extinction events across species ranges were only marginally affected by climate change between the two survey periods. Surprisingly, these events were more profoundly influenced by the climatic conditions present at the time of the initial surveys.
Role of Local Populations and Networks
One significant determinant of whether a new area was colonized, or a population went extinct was the proximity of other populations of the same species. This close proximity facilitated colonizations and minimized extinctions, likely due to the dispersal of birds from neighboring regions.
This insight underscores the crucial role of preserving networks of local populations to reduce extinctions and strengthen the resilience of populations against climate change impacts. The study findings will be published today (July 20) in the journal Nature Communications.
Interpretations and Insights from the Research Team
Joint study-lead Professor Stephen Willis of Durham University’s Department of Biosciences said: “Our findings potentially show two intriguing responses to recent climate change. In some areas ‘colonization lags’ may result in species being unable to track improving climate, perhaps due to habitat or prey not yet being available in new sites.
“By contrast, fewer extinctions occurring in areas where we predict them to occur might be evidence of ‘extinction debts.’
“Such debts occur when species are committed to eventual extinction due to unfavorable climate, but they nonetheless manage to persist, sometimes for lengthy periods, because key limiting factors, such as their preferred habitat, take some time to alter.”
Non-Climatic Factors
Joint first-author, Dr. Christine Howard added: “The key role of non-climatic factors in altering range changes highlights that climate is just one factor impacting populations of European breeding birds.
“The role of factors such as persecution in limiting European birds highlights that such things are still a major problem for many species. However, the rapid recovery of some species from past persecution or poisoning provides hope that populations can often rebound once such impacts are controlled.”
Co-author, Dr. Sergi Herrando, who led on collating data for the most recent distribution atlas, added: “The work presented here highlights the ways in which coordinated survey data, collected across many countries, can be used to better understand the causes of species losses and gains.
“The collection of data used in this study involved huge numbers of people. The second breeding atlas alone collated data from 120,000 field workers, permitting a systematic survey of 11 million square kilometers across 48 countries.”
Reference: “Local colonisations and extinctions of European birds are poorly explained by changes in climate suitability” by Christine Howard, Emma-Liina Marjakangas, Alejandra Morán-Ordóñez, Pietro Milanesi, Aleksandre Abuladze, Karen Aghababyan, Vitalie Ajder, Volen Arkumarev, Dawn E. Balmer, Hans-Günther Bauer, Colin M. Beale, Taulant Bino, Kerem Ali Boyla, Ian J. Burfield, Brian Burke, Brian Caffrey, Tomasz Chodkiewicz, Juan Carlos Del Moral, Vlatka Dumbovic Mazal, Néstor Fernández, Lorenzo Fornasari, Bettina Gerlach, Carlos Godinho, Sergi Herrando, Christina Ieronymidou, Alison Johnston, Mihailo Jovicevic, Mikhail Kalyakin, Verena Keller, Peter Knaus, Dražen Kotrošan, Tatiana Kuzmenko, Domingos Leitão, Åke Lindström, Qenan Maxhuni, Tomaž Mihelič, Tibor Mikuska, Blas Molina, Károly Nagy, David Noble, Ingar Jostein Øien, Jean-Yves Paquet, Clara Pladevall, Danae Portolou, Dimitrije Radišić, Saša Rajkov, Draženko Z. Rajković, Liutauras Raudonikis, Thomas Sattler, Darko Saveljić, Paul Shimmings, Jovica Sjenicic, Karel Šťastný, Stoycho Stoychev, Iurii Strus, Christoph Sudfeldt, Elchin Sultanov, Tibor Szép, Norbert Teufelbauer, Danka Uzunova, Chris A. M. van Turnhout, Metodija Velevski, Thomas Vikstrøm, Alexandre Vintchevski, Olga Voltzit, Petr Voříšek, Tomasz Wilk, Damaris Zurell, Lluís Brotons, Aleksi Lehikoinen and Stephen G. Willis, 20 July 2023, Nature Communications.
DOI: 10.1038/s41467-023-39093-1
The research was funded in part by the National Environment Research Council, part of UK Research and Innovation.
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