- Dendroica petechia
Identification:
L. 4 in
- Thin, pointed bill
- Mostly yellow plumage
- Upperparts greenish-yellow
- Yellowish legs
- Plain yellow face with yellow eye ring
Male
- Golden yellow
- Rusty streaks on breast and flanks
Female
- Plain yellow
- Streaks on breast absent or barely present
Some have pale gray wash to plumage (southwestern US)
In the tropical parts of its breeding range this bird (especially the male) may have a chestnut head or crown patch.
Habitat:
In the US, inhabits moist thickets, especially along streams and in swampy areas, gardens, overgrown pastures, and woodland edges, it is more limited to riparian habitat in the west than the east.
The erithachorides group (see Distribution and Taxonomy) mainly belongs in mangroves, while the petechia group exhibit geographical variation in its habitat choice, ranging from mangroves to coastal scrub to highland moist forest depending on the island.
Distribution and Taxonomy
Breeds within North America from Alaska east across Canada to Newfoundland and south to southern California, northern Oklahoma, and northern Georgia; local in southern Florida; these subspecies which belong to the aestiva group of subspecies which winters in tropics. Additionally found in a number of largely non-migratory subspecies in the Caribbean (the petechia = "golden warbler" group), and in Mexico, Central America and northern South America (the erithachorides = "mangrove warbler" group). In total, there are thirty-four subspecies. The three groups mentioned have previously been considered separate species but are now considered one wide-ranging species.
Behaviour
Breeding
4 or 5 pale blue eggs, thickly spotted with brown, in a well-made cup of bark, plant fibers, and down, placed in an upright fork in a small sapling.
Voice
Song
Bright, musical sweet-sweet-sweet, sweeter-than-sweet; there is some geographical variation
Call
A sharp chip
Discussion
This is one of the most widespread New World warblers, showing great geographical variation. In temperate North America the Yellow Warbler is one of the principal victims of the Brown-headed Cowbird, which lays its eggs in the nests of other birds. A cowbird lays only one egg per foster nest, but she may lay eggs in four or five nests in a short time, thus jeopardizing many broods. If the female Yellow Warbler discovers a cowbird parasitizing her nest, she quickly covers the alien egg with a new foundation and lays another clutch. Occasionally a nest is found with up to six layers, each containing one cowbird egg. The situation is equally bad in the tropical part of its distribution, leading to for example the Barbados race being considered endangered due to Shiny Cowbird nest parasitism.
