The pied flycatcher, pictured here, is just one of hundreds of bird species across five continents whose migration patterns over time were analyzed in a study by University of Edinburgh.
After looking at records of migration patterns going as far back as 300 years, the researchers found that migrating birds are arriving to summer breeding grounds about one day earlier per degree of increasing global temperature. The shift in timing potentially has serious consequences, since food availability, nesting opportunities, and the timing of laying and hatching eggs are all on a tight schedule.
The Guardian reports:
[The researchers] hope their study, published in the Journal of Animal Ecology and supported by the Natural Environment Research Council, will help scientists better predict how different species will respond to environmental changes. Long-distance migrants, which are shown to be less responsive to rising temperatures, may suffer most as other birds gain advantage by arriving at breeding grounds ahead of them.
Last year, sandhill cranes in the U.S. illustrated this trend by showing up at stopover grounds on their migration to northern nesting grounds early, hitting peak numbers ahead of schedule.