Black-throated Blue Warbler
Common Name:
Black-throated Blue Warbler
Class: Aves
Order: Passeriformes
Family: Parulidae
Genus:
Setophaga
Species:
Setophaga
caerulescens
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P hoto: Steven Pitts |
TAXONOMY
Black-throated Blue Warblers
are passerines in the Parulidae family which groups them
together with other Wood Warblers. They are about 5.25
inches (13cm) in size. Males have white
upperparts and blue upperparts. They also have a black
face, throat and sides. They have a white patch at the
base of their primaries. Females overall are a
light brown color with a gray crown and cheek patch and white supercilium. They have grayish and yellowish underparts. These male and
female Warblers differ more than any other Wood
Warbler that early naturalists identified them as two
different species.

Photo: M. Noonan
HABITAT/DIET
Black-throated Blue Warblers
live in undisturbed mixed and deciduous forests with
thick undergrowth and rhododendron bogs. They breed in
northeastern United States and southern Canada. They are
as far south as the Appalachian Mountains.
Black-throated Blue Warblers winter in the Greater
Antilles. They are among one of the most studied passerine
species in North America. This is because it is one of
the few migratory species that has been observed in both
breeding and wintering sites. They can be found in
Western New York in the summer. Black-throated Blue Warblers
eat fruit and insects about the ground while hovering.
They eat mostly insects during the breeding season and
will eat more plant material during the winter season.
BEHAVIOR
Male Black-throated Blue
Warblers are one of the more aggressive warbler species
where it is fairly common to see birds from adjoining
territories fighting over the border between two
territories. When one male flies across this border the
other male will fly quickly toward the intruder and
gives a rapid series of chirps. If the other bird does
not leave he will chase him in circles for as far as 300
feet. Sometimes these bird may even physically fight one
another hitting the other bird with their wings,
pecking, and locking their feet together to force the
other bird to the ground. Black-throated
Blue Warblers are thought to be monogamous but it is not
known how many broods they have per year. The female
lays and incubates about 4 creamy colored eggs for 12-13
days. The young are altricial which means they are
blind, helpless and immobile. Both parents tend to the
young until the young are ready to fledge which is 12-13
days after hatching.