biogeography

From Jillian Mock at Audubon: Hummingbirds come in a jewel-like assortment of colors and are so dexterous, they can hover still for seconds and fly backward. They also have one of the most diverse avian families in the world, boasting about 350 known species across North and South America. Sunbirds, the prime nectar-feeding birds of the Old World, have fewer than 150. But once upon a time, tens of millions of years ago, hummingbirds did zip around the hills and forests of Europe. According to Jim McGuire, it all started about 42 million years ago, when hummingbirds broke away from the swifts, their closest living relatives. McGuire, an integrative biologist at University of California Berkeley, calculated this date by examining Read More ›