eBird, a joint project of Audubon and the Cornell Lab of Ornithology, has been tracking bird sightings for some time, amassing a remarkable amount of data about where and when birds occur in North America. Now, the folks at eBird have created these incredible video representations of how birds come and go through the seasons. With spring nearly upon us, this is a great reminder of the wonders of migration. One of our favorites is the one for Swainson's Hawk, which hits the California Central Valley in great numbers in the spring. Watch for that area to light up on the map. (photo of Swainson's Hawk by USFWS)