Cerulean Warbler (adult male) Eggers Woods Chicago Cook County IL May 2013 Jeff Skrentny FB0518 IMG_1852
alarm calls, 2 to 6 "dee"s
made by multiple birds
Eurasian Tree Sparrow (adult) Chautauqua National Wildlife Refuge Goofy Ridge Mason County IL June 2012 Jeff Skrentny IMG_2943
Lincolns or Song Sparrow. Small bill, solitary, deep in reeds, near open grass and water. Broad eyebrow. Seems like Lincoln to me?
Birds (class Aves or clade Avialae) are feathered, winged, two-legged, warm-blooded, egg-laying vertebrates. Aves ranks as the tetrapod class with the most living species, approximately ten thousand. Extant birds belong to the subclass Neornithes, living worldwide and ranging in size from the 5 cm (2 in) Bee Hummingbird to the 2.75 m (9 ft) Ostrich. The fossil record indicates that birds emerged within the theropod dinosaurs during the Jurassic period, around 150 million years ago. Birds are the only living...