Audubon's Warbler

The Audubon's Warbler, Dendroica (coronata) auduboni, is a small New World warbler.

This passerine bird is closely related to its eastern counterpart, Myrtle Warbler, and the two forms are frequently lumped as the single species Yellow-rumped Warbler, Dendroica coronata. It is likely that the two forms diverged when the eastern and western populations were separated in the last ice age.

Audubon's Warbler has a westerly distribution, with Myrtle further east. It breeds in much of western Canada, and the western USA into Mexico. It is migratory, wintering from the southern parts of the breeding range into western Central America.

The summer male Audubon's Warbler has a slate blue back, and yellow crown, rump and flank patch. It has white tail patches, and the breast is streaked black. The female has a similar pattern, but the back is brown as are the breast streaks.

This form can be distinguished from Myrtle Warbler by its lack of a whitish eyestripe, a yellow throat, and concolourous cheek patch.

The breeding habitat is a variety of coniferous and mixed woodland. Audubon's Warblers nest in a tree, laying 4-5 eggs in a cup nest.

These birds are insectivorous, but will readily take berries in winter, when they form small flocks.

The song is a simple trill. The call is a hard check.

Reference

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