In a nutshell A newly discovered 69-million-year-old bird skull from Antarctica proves that modern birds were already diverse ...

The American tree sparrow often occurs in flocks of up to 50 birds. In habitat and behavior, they are much like field sparrows, but American tree sparrows are more frequent at bird feeders.

DESCRIPTION: The medium tree finch is a chunky, wren-like finch. The male has a black head, grayish-brown upperparts, and whitish or yellowish underparts. The female has a grayish-brown head. HABITAT: ...