Yellow Warbler

The Yellow Warbler, Dendroica petechia, is a New World warbler. It is the most widespread Dendroica warbler, breeding in almost the whole of North America and down to northern South America. It has 35 geographical races, which can be divided into three main groups.

The "Yellow Warbler", aestiva, group, which could possibly be considered a separate species, breeds in the whole of North America as far south as central Mexico in open, often wet, woodland or shrub. It is migratory, wintering in Central and South America. This form is a very rare vagrant to western Europe.

The summer males of this group are greenish above and yellow below, with red breast streaking. The various aestiva races vary mainly in brightness.

The "Mangrove Warbler", erithacoroides, group is resident in the mangrove swamps of coastal Central America and northern South America. The summer males differ from aestiva Yellow Warblers in that they have rufous hoods. The races in this group vary in the extent and hue of the hood.

The "Golden Warbler", petechia, group is resident in the mangrove swamps of the West Indies. The summer males differs from aestiva Yellow Warblers in that they have a rufous crown or hood. The races in this group vary in the extent and hue of the head patch.

Other plumages of all races are essentially greenish above and a duller yellow below, although young males soon acquire breast and, where appropriate, head colouration.

Yellow Warblers nest in trees, building a cup nest. Aestiva lays 3-6 eggs, but the two other groups, which breed in mangroves, lay fewer eggs, as would be expected for tropical races.

These birds feed on insects and spiders, but northern races will also take some berries.

The song is a musical sweet sweet sweet, I'm so sweet, although it varies considerably between races. The call is a soft or harder ship.

This species is a regular victim of the Brown-headed Cowbird, a nest parasite.

Reference

New World Warblers by Curson, Quinn and Beadle, ISBN 0-7136-3932-6