Bird Database

Canada Warbler

(Cardellina canadensis)

State of the Birds
At a Glance



Long distance


Strongly Decreasing


Habitat loss and fragmentation, Predation, Collisions

Conservation Actions

Maintain large unfragmented forest blocks

Canada Warbler

(Cardellina canadensis)

The Canada Warbler is a bird of moist forests and swamps over most of its range and can be found in both coniferous and deciduous habitats. Key microhabitat features typically include a dense understory and mossy ground cover. Even though breeding habitat often has standing water, the nest is usually built on the ground, albeit on a hummock, upturned root mass, or other slightly raised area. It is also usually concealed by some sort of overhang, including living vegetation, fallen slicks or logs, or dead leaves.

A female will lay 4-5 eggs, but research on paternity in this species has shown that these are not necessarily all from the same male. In a study in New Hampshire, roughly half the young raised had a male parent different from the one mated to the nesting female. Both males and females will seek out mating opportunities with birds other than their immediate mate, presumably to diversify the genetics of their offspring. Such fooling around is not atypical in songbirds that we typically think of as forming a durable pair bond over the course of a breeding season.

Like many of our long-distance migrants, Canada Warblers are declining, although in some parts of their range to the north this decline may have slowed down. Habitat loss has often been implicated in the decline, including forest fragmentation and loss of understory shrubs (e.g., due to over-browsing by deer). Forest maturation may be another factor, as such forests often have less developed shrub layers and some forms of forest thinning (including severe storms) create conditions where this layer can quickly regenerate. There is also concern about habitat loss in the Canada Warbler’s winter range in the northern Andes. Although it frequently uses disturbed habitats in parts of South America, even these are at risk as development and agriculture expand with increasing human populations.

Seasonal Abundance

Relative abundance based on eBird data. Numbers indicate likelihood of finding this species in suitable habitat at a given time of year, not actual numbers encountered.

Canada Warbler
Range Map

Information for the species profiles on this website was compiled from a combination of the sources listed below.

  • The Birds of New Hampshire. By Allan R. Keith and Robert B. Fox. 2013. Memoirs of the Nuttall Ornithological club No. 19.

  • Atlas of the Breeding Birds of New Hampshire. Carol R. Foss, ed. 1994. Arcadia Publishing Company and Audubon Society of New Hampshire

  • Birds of the World. Various authors and dates. Cornell Laboratory of Ornithology.

  • Data from the Breeding Bird Survey

  • Data from the Christmas Bird Count