Published on: March 16, 2022, 8:05 p.m.
Disruptions in the air
Garden warblers saw a decrease in offspring by 26 per cent, which can be detrimental to the species
Woe to birds!
A new study finds that climate crisis is transforming European birds
A new study has found that the climate crisis is causing major disruptions to European birds, from shifting their nesting dates to decreasing their chick numbers to even changing their general body sizes, reported The Guardian.
The study, published in the Proceedings of the National Academy of Sciences, found that rising temperatures and non-temperature effects of climate change are transforming European birds, such as garden warblers, chiffchaffs, and crested tits.
The authors focused on data collected on 60 species in Britain since the mid-1960s, reviewing changes in egg-laying, body form, and number of offspring. From there, researchers determined what impacts were caused by higher temperatures and what other factors played a role in these transformations.
More than half, about 57 per cent, of the effects were linked to increasing temperatures, but other factors, like habitat loss, pollution, invasive species, and diseases, also contributed. About 32 per cent of the 60 species studied experienced body changes related to heat stress. The researchers found that 86 per cent of birds in the study experienced a shift in egg-laying dates, with 31 per cent of the 60 birds also experiencing a change in the regular number of offspring.
"For example, climate change caused chiffchaffs to lay their eggs six days earlier over the last 50 years, but other unknown environmental factors led to an additional six days, meaning in total they now lay their eggs 12 days earlier than they did half a century ago," Martijn van de Pol, lead author of the paper from James Cook University in Australia, told The Guardian.
Similarly, garden warblers saw a decrease in offspring by 26 per cent, which can be detrimental to the species. While some species are experiencing lower offspring numbers and shrinking body sizes, some of the birds in the study faced opposite impacts. Redstarts are growing larger and having more offspring.
The study highlights that while warming is clearly causing challenges for bird species, there are other factors that need attention, too.
"As we increase our understanding of how changes in climate directly impact species and how non-climatic variables simultaneously drive changes, we can better identify those species or populations most at risk from climate change," the study said.