Birds are Laying Eggs Earlier than Predicted

Over 100 years ago, egg collection enthusiasts realized their hobby would prove crucial for understanding nature and how it affects birds. They probably never imagined their work would help scientists understand how a changing climate affects birds today. Using a modern and a Victorian-era collection of egg samples, Researchers found that several bird species in the Chicago area nest and lay Eggs almost an entire month earlier than they did a century ago.

The new study about Eggs was published Friday in the Journal of Animal Ecology. Of the 72 species documented in their data, a third have been nesting earlier. On average, birds that changed their nesting habits laid Eggs around 25 days laid Eggs prematurely. The researchers studied egg collections from the Field Museum in Chicago, the Western Foundation of Vertebrate Zoology, and the Chicago Academy of Sciences.

Researchers looked at rising temperatures to explain the shift in behavior. Most of the birds in the data eat insects, and those insects eat plants, so the whole ecosystem is connected, said John Bates, curator of birds at the Field Museum and the study’s lead author. The results of this study are consistent with the patterns in insect and plant communities.

Of the two analyzed Eggs collections, the first included data from 1880 to 1920. The second set ranges from 1990 to 2015, leaving a hearty gap of missing information. Researchers said the gap resulted from a decreased interest in the hobby of egg collecting after 1920.