The Canada Warbler is a small forest songbird with blueish-grey upperparts that contrast with its bright yellow underparts. The male has a bold necklace of black stripes and yellow eye rings (that look like spectacles!). Females are similar but less brightly colored. Unlike most birds, the Canada Warbler keeps the same plumage throughout the year.
The Canada Warbler breeds in every Canadian province and territory except Nunavut and Newfoundland and Labrador. Approximately 80% of the breeding range and 85% of the breeding population is in Canada. It is one of the last migratory songbirds to arrive to its breeding grounds, between from late-May and early-June, and is one of the first species to begin its migration to its wintering grounds, between mid-August and early-September. The species winters in and east of the Andes in South America.
As primarily an insectivorous species, it feeds on mosquitoes, flies, moths, butterflies, beetles, worms, and snails. Preferred habitat varies across its range from east to west, but in general the species breeds in moist mixed wood or deciduous forests with a dense shrub layer, complex understorey, and tall trees. It prefers old-growth forests near a body of water or a stream.
The Canada Warbler faces a variety of threats throughout its life cycle. On the breeding grounds this includes habitat loss and degradation, deforestation, removal of the shrub layer, reduced availability of insect prey, and in breeding populations near rural areas and cities, the Canada Warbler may be vulnerable to cat predation as it forages and nests on or near the ground. Also, during migration, the species is particularly vulnerable to collisions with windows. Land conversion (e.g. the removal of forest for agriculture, human settlements, or resource development purposes) is leading to the loss of both breeding and nonbreeding habitat, greatly reducing habitat availability.
The Canada Warbler population declined by 71% between 1970 and 2012. In Canada the Canada Warbler is listed as Threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and is on Schedule 1 of the Species at Risk Act (SARA).
Nature Canada is a proud partner of the Canada Warbler International Conservation Initiative (CWICI). The CWICI is a multinational collaboration to support and coordinate recovery efforts for the Canada Warbler through acquiring and applying the best science. In order to protect this migratory species a “full life-cycle” approach is required. Threats on the breeding grounds, wintering grounds, and during its migration must be understood if they are to be mitigated or removed. To find out more about CWICI, please visit our webpage.
Look for next week’s blog about what you can do to help this threatened species!
Sources: Recovery Strategy for the Canada Warbler in Canada, Species at Risk Public Registry, and Species at Risk in Ontario List.
Photo by Zak Pohlen.