The Tree Swallow is a migratory passerine bird that breeds in North America and winters in Mexico, Central America and the Caribbean. It is a very rare vagrant to western Europe.
This swallow averages 13.5 cm long and weighs about 20 g. The bill is tiny. The adult Tree Swallow has iridescent blue-green upperparts, white underparts, and a very slightly forked tail. The female usually has duller colours than the male, often more greenish than the more bluish male. The juvenile plumage.. more