But how did all the amazingly coloured different bird species arise? Nearly all birds with bright red, orange, and yellow feathers or bills use a group of pigments called carotenoids to produce ...
When red-billed and yellow-billed finches mate ... evolves and may help explain similar color variations seen in other bird species around the world. More information: Daniel M.
A very close relative of the Yellow-bellied and Red-naped sapsuckers, replacing them on the Pacific slope. It was considered to belong to the same species for some time, so differences in behavior ...