Climate Wire | As part of their annual spring migration, millions of birds fly north to settle in their summer homes and prepare to raise their young. However, some species may welcome fewer babies.
A new study finds that many bird species are reducing their offspring numbers as global temperatures rise. And large migratory birds are most affected.
published on monday Proceedings of the National Academy of SciencesThe study examined data from over 200 bird populations covering over 100 different species on Earth. Scientists, including dozens of collaborators from around the world, have investigated changes in the number of offspring produced by these populations over the past 50 years.
During this time, global temperatures have increased by nearly 1 degree Celsius. The researchers used the model to investigate the relationship between temperature rise and offspring production in the populations studied.
Researchers found that about 43% of the species studied produced more offspring over time, while nearly 57% produced fewer offspring. Taken together, this means that bird populations have declined slightly overall.
But when zooming in on individual species, researchers found that some birds were far more endangered than others. was highly sexual. The same is true for migratory birds compared to birds that stay in the same place all year round.
The findings suggest that small, non-migratory birds may be adapting more quickly to climate change. And in some cases, they may even benefit from rising temperatures.
For example, the study found that species that raise multiple chicks per season tended to have higher nesting success in warmer temperatures. This means that chicks have a higher chance of survival after spawning. Although it’s not entirely clear why, scientists believe that warmer spring temperatures can provide more vegetation earlier in the season, providing more food and allowing birds to better hide their nests from predators. It is suggested that this may be because it is possible.
Larger and migratory birds, on the other hand, may be slower to adapt to increased temperatures. This is a factor that can slow a species’ ability to adapt to environmental changes.
The study has several caveats, the researchers warn.
Data for the tropics are relatively scarce, with more emphasis on coastal regions than on central continents. Species concentrating on these blind spots may be experiencing different trends.
However, the study flags another possible pattern regarding the winners and losers of climate change.
This is just one of the many ways that global warming is altering the life cycle and evolution of birds around the world. Some studies suggest that temperate worlds may favor smaller birds over larger ones. is known to actually shrink over time.
The reasons for this are still not entirely clear, but scientists have several theories.
Smaller bodies tend to dissipate heat more easily, which helps animals regulate their body temperature more efficiently in warmer climates. small animals may be better suited to compete for limited resources.
At the same time, many studies have found that climate change is affecting bird migration patterns, causing many species to set out on their annual journeys earlier in the season.
Reprinted from E&E News with permission of POLITICO, LLC. Copyright 2023. E&E News provides essential news for energy and environmental professionals.
