European breeding birds respond slowly to recent climate change, study finds

Over the past 30 years, European breeding birds have shifted their range by an average of 2.4 km per year, according to new research published today. Natural communication.

However, these changes differed significantly from expectations based on the changing climate and topography during that period. Based on climate alone, the researchers predict that species’ average range shifts must have been about 50% faster.

The study, led by experts from Durham University in England, used survey data collected as part of two Europe-wide bird distribution atlases published 30 years apart.

The researchers found that local colonization and extinction events across species ranges were only weakly affected by climate change between the two survey periods. Instead, they were more affected by climatic conditions at the time of the first surveys.

One of the main factors that determines whether a new area is colonized or a population becomes extinct is the extent to which other populations of other species are nearby in the area, which facilitated colonization and reduced extinctions, presumably by dispersal of birds from neighboring areas. .

The finding highlights the importance of maintaining local population networks to limit extinctions and make populations more robust to the effects of climate change.

„Our findings show two intriguing responses to recent climate change,” said joint study-leader Professor Stephen Willis, from Durham University’s Department of Biology. , that fewer extinctions occur in areas where we predict them to occur may be evidence of 'extinction debts’.

„Such debts occur when species die out due to unfavorable climates, although they sometimes persist over long periods of time because key limiting factors, such as their preferred habitat, take some time to change.”

Joint first-author Dr Christine Howard added, „The important role of non-climatic factors in driving range shifts highlights that climate is only one factor affecting European breeding bird populations.

„The role of factors such as harassment in controlling European birds highlights that such things are still a major problem for many species. However, the rapid recovery of some species from past harassment or poisoning gives hope that populations will often rebound once such impacts are controlled.”

Dr. Co-author, who led the compilation of data for the most recent distribution atlas. Sergey Herando added, „The work presented here highlights how integrated survey data collected across multiple countries can be used to better understand the causes of species losses and gains.

„The collection of data used in this study covers a large number of people. The Second Breeding Atlas alone compiled data from 120,000 field workers, allowing a systematic survey of 11 million square kilometers in 48 countries.”