Spring is in the air. Birds are singing and beginning to build their nests. It happens every year, like clockwork. But a new study in the Journal of Animal Ecology shows that many species of birds are nesting and laying eggs nearly a month earlier than they did a hundred years ago. By comparing recent observations with century-old eggs preserved in museum collections, scientists were able to determine that about a third of the bird species nesting in Chicago have moved their egg-laying up by an average of 25 days. And as far as the researchers can tell, the culprit in this shift is climate change.
“Egg collections are such a fascinating tool for us to learn about bird ecology over time,” says John Bates, curator of birds at the Field Museum and the study’s lead author. “I love the fact that this paper combines these older and modern datasets to look at these trends over about 120 years and help answer really critical questions about how climate change is affecting birds.”
Bates got interested in studying the museum’s egg collections after editing a book about eggs. “Once I got to know our egg collection, I got to thinking about how valuable that collection’s data are, and how those data aren’t replicated in modern collections,” he says.
Read more at Field Museum
Image: A drawer from the Field Museum's egg collections. (Credit: Bill Strausberger)