Birds are often considered highly adaptable, but a new report from the National Wildlife Federation claims that many species are struggling as the climate changes. In Arizona, the effects are seen in the more than 500 species that migrate – including 150 species of hummingbirds.
NWF senior scientist Doctor Doug Inkley says people may assume that migratory birds have an advantage because they can fly to different places.
Inkley says one problem with changing flight patterns and timing is that the birds show up at the wrong times for their natural food sources. The "Shifting Skies" report cites climate change as the biggest threat to birds in this century.