Over the past few millennia, human-caused habitat change has had one of the most profound effects on bird populations globally, especially since industrialization in the 1800s. Looking forward, we can expect human-caused habitat loss to represent the greatest threat to many North American breeding birds. The problem will be most severe on their wintering grounds, according to a new study published today in the journal Global Change Biology by a international research team including representatives from the Cornell Lab, Environment and Climate Change Canada, and VU University Amsterdam. By the end of this century, the study’s authors say predicted changes in rainfall and temperature will compound the problem for birds that breed in eastern North America and winter in Central America. The data source for this research? Your eBird checklists.