The findings appear in the Proceedings of the Royal Society B journal. The loud chirp sound is produced by male Anna's hummingbirds (Calypte anna) as the birds dive towards the ground at speeds that ...

Berkeley -- The beeps, chirps and whistles made by some hummingbirds and thought to be vocal are actually created by the birds' tail feathers, according to a study by two students at the University of ...

Many of the world's smallest hummingbirds, including the West Coast's Anna's and the East Coast's ruby-throated, execute display dives to seduce females and drive away intruders. A characteristic ...