tinny pit call and twitters distinct from Anna’s. Costa’s generally plainer on throat and underparts, without dusky throat spotting. See black-chinned hummingbird.

Engineers at Stanford University in California found that Anna's Hummingbird (pictured) is more efficient than the best micro helicopter Think the ratio of the bird's wings make it so efficient ...

But high-speed cameras show us what makes these birds perfect flying machines. A captive Anna’s hummingbird feeds while hovering before an optical illusion in a reenactment of an experiment that ...

An Anna’s hummingbird calls out from the bare branch ... This hardy hummingbird has the northernmost year-round range of any ...