Data from: Drivers of climate change impacts on bird communities

1. Climate change is reported to have caused widespread changes to
species’ populations and ecological communities. Warming has been
associated with population declines in long-distance migrants and habitat
specialists, and increases in southerly distributed species. However, the
specific climatic drivers behind these changes remain undescribed. 2. We
analysed annual fluctuations in the abundance of 59 breeding bird species
in England over 45 years to test the effect of monthly temperature and
precipitation means upon population trends. 3. Strong positive
correlations between population growth and both winter and breeding season
temperature were identified for resident and short-distance migrants.
Lagged correlations between population growth and summer temperature and
precipitation identified for the first time a widespread negative impact
of hot, dry summer weather. Resident populations appeared to increase
following wet autumns. Populations of long-distance migrants were
negatively affected by May temperature, consistent with a potential
negative effect of phenological mismatch upon breeding success. There was
evidence for some nonlinear relationships between monthly weather
variables and population growth. 4. Habitat specialists and
cold-associated species showed consistently more negative effects of
higher temperatures than habitat generalists and southerly distributed
species associated with warm temperatures. Results suggest that previously
reported changes in community composition represent the accumulated
effects of spring and summer warming. 5. Long-term population trends were
more significantly correlated with species’ sensitivity to temperature
than precipitation, suggesting that warming has had a greater impact on
population trends than changes in precipitation. Months where there had
been the greatest warming were the most influential drivers of long-term
change. There was also evidence that species with the greatest sensitivity
to extremes of precipitation have tended to decline. 6. Our results
provide novel insights about the impact of climate change on bird
communities. Significant lagged effects highlight the potential for
altered species’ interactions to drive observed climate change impacts,
although some community changes may have been driven by more immediate
responses to warming. In England, resident and short-distance migrant
populations have increased in response to climate change, but potentially
at the expense of long-distance migrants, habitat specialists and
cold-associated species.