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Black Throated Green Warbler

With a name like this you would think that the Warbler is some sort of comic book villain! The Black-throated Green Warbler is actually a traveling bird. The species breeds across the boreal forests of Canada and the north eastern United States, and winters in Mexico and Central America. Although common in some areas of suitable habitat in Alberta, little is known about its ecology in the province. Recent concerns over the destruction and loss of its breeding habitat through forest harvesting have led to the Black-throated Green Warbler being included on the Blue List of species that may be at risk of extirpation in Alberta.

In almost all cases, the Black-throated Green Warbler is classified as a forest specialist: it inhabits larger pieces of forest and tends to avoid disturbed or edge habitats and small forest patches. Recent work in Alberta reveals a consistent association of the Black-throated Green Warbler with deciduous or coniferous dominated mixedwood forests, with a dependence on the presence of some coniferous canopy trees.

The Black-throated Green Warbler is almost entirely insectivorous. Meaning it eats mostly bugs! Breeding birds tend to take a high volume of butterfly and moth larvae, but will try to find other abundant prey such as midges (mosquito-like bugs) along a lakeshore. This warbler is also known to chow down on beetles, true bugs, wasps, ants, gnats, moths, flies, spiders, and mites. Yummy! Unlike several other related wood warbler species, the Black-throated Green Warbler is not known as a major predator of Spruce Budworms (a destructive pest of coniferous trees), except when the insect is at epidemic levels. Most food finding by the Black-throated Green Warbler is done during the day, and involves picking insects off leaves or small branches, but birds will also hover at branch tips and 'hawk' insects in midair. During wet weather individuals will look for food more along the bark and trunks of trees, and during migration they will also eat berries and other vegetative material. These particular Warblers arrive in Alberta from mid to late May. Very few spring migrants are ever observed in southern Alberta, suggesting that most birds enter the province from the east. Males arrive several days earlier than females, and immediately begin establishing territories by singing and exhibiting aggression towards other males.

Black-throated Warbler

Black-throated Warbler

Black-throated Warbler

Black-throated Warbler