In the past, hurricanes have blown migrating birds from the East Coast all the way to the Great Lakes and into Canada, according to Peg Abbott, owner of Naturalist Journeys. As Sandy hit, she said the warblers and smaller birds had already gotten where they were going, and it was the eagles, hawks and larger birds of prey who were on the move.
The timing of migration is all about diet, said Abbott. "Those birds that eat insects leave first, and then those that feed higher up the food chain on other birds or on small mammals. Once their prey leaves, they've got to go as well. As the prey species either go into their dormant cycle or die off, then they have to leave because there's no food on the table."
Abbott said climate change is making migration more precarious every year because birds depend on certain food sources being available at certain times and places along their migratory routes, e.g., the budding of a particular flower that attracts insects for migrating warblers to eat, or the hatching of crabs on a particular beach for migrating sea birds to eat. Climate change has put the timing out of sync, she said, and will be "all over the map in the next decade."