Several species of birds are nesting and laying eggs nearly a month earlier, according to a recent study. The study was published in the Journal of Animal Ecology. It explains how a warmer climate is forcing spring to arrive sooner in most parts of the United States. Important natural phenomena like migration and reproduction are being thrown off, as well as pest and allergy seasons are being extended.
“It was shocking to find this,” said John Bates. He is the curator of birds at the Field Museum and the study’s lead author. “What we can see is clearly pointing in the direction that climate change is having a significant effect on the behavior of birds. It’s another piece of the puzzle we are trying to figure out in terms of impacts.”
Birds are laying eggs significantly earlier than 100 years ago
Scientists in the United States studied bird nesting trends using egg samples gathered in the Chicago area. They discovered that over a third of the 72 species for which historical and present data is available are now nesting significantly earlier in the year than they were previously. Bluejays, yellow warblers, and field sparrows are laying earlier than they did 100 years ago, according to the study. The heating of the atmosphere caused by the use of fossil fuels appears to be upsetting a seemingly unstoppable process.
Most of the birds in the data eat insects, and those insects eat plants. So the whole ecosystem is connected, said Bates. “These stresses haven’t necessarily doomed anything to extinction, but they’re definitely changing the conditions that all of these organisms are dealing with,” said Bates. “And that may have really important ramifications and anything like that has potential research locations for humans, too.”
Research published in 2020 found that about 3 billion birds had vanished from the United States and Canada since 1970. It accounts for nearly a third of all bird populations. The losses have been “staggering,” according to researchers. Sparrows, blackbirds, warblers, and finches are suffering the most. Another study discovered that migrating birds in North America are diminishing as a result of climate change. A follow-up study found that birds with larger brains, as compared to their physical size do not shrink as much as those with smaller brains.