Boreal chickadee  (Parus hudsonicus)

The boreal chickadee is classified as Least Concern (LC) on the IUCN Red List (1).

A small songbird, the boreal chickadee (Parus hudsonica) is, as its name suggests, almost entirely restricted to the boreal forests of North America (3). Very similar in appearance to other chickadees in its range, the boreal chickadee has a brown body and a brown cap, with bright reddish flanks and undertail-coverts (2).

The top of the head and the back of the neck often have a greyish tinge, which extends down the sides of the head to below the eye. A white stripe runs from the base of the bill to below the eye, while the chin and throat are black (2). The back, wings, rump and uppertail-coverts of the boreal chickadee are generally pale grey-brown, and the breast and abdomen are white. The juvenile boreal chickadee is very similar to the adult in appearance, although its colouration is usually slightly duller (2) (4).

The boreal chickadee inhabits the northern coniferous forests of North America, breeding throughout Alaska, Canada and the northernmost states of the U.S. (2).

Somewhat unusually for a North American passerine, the boreal chickadee is a permanent resident of boreal forests. It occurs primarily in coniferous spruce and fir forests, often at high elevations (2) (4). It may occasionally be found in mixed woodlands (3).

Insects and spiders, including their eggs and larvae, make up the majority of the boreal chickadee’s diet. It will also take seeds, especially during winter (2) (4). An opportunistic species, the boreal chickadee forages by hopping on twigs and branches, gleaning food off the surface of the tree or probing into crevices in the bark. It will occasionally hover in front of branches, and will hangs upside-down to get at the undersides of branches, cones and needles (2) (4).

The boreal chickadee frequently stores ‘parcels’ of food in storage points, such as in bark crevices, under lichen and between spruce needles (5). This behaviour allows the boreal chickadee to cope with the harsh boreal environment during winter and other periods of food scarcity (2) (4) (5) (6).

The breeding season of the boreal chickadee typically begins around May, when breeding pairs will defend small territories (4) (7). The boreal chickadee nests in cavities in trees, which both the male and female excavate prior to mating. The pair inspects a number of holes and cavities together, although it is usually the female that begins the initial excavation of the chosen cavity (2) (4) (7). The boreal chickadee often enlarges an existing hole in a tree, but it will also use old woodpecker holes, and has been observed using the earth beneath exposed tree roots for nest sites (2) (4). The nest itself is usually lined with a combination of dry moss, pieces of bark, hair, fur, feathers, lichen or ferns (2) (4).

The boreal chickadee produces a clutch of four to nine eggs, which are incubated solely by the female. Incubation generally lasts for around 15 days, during which time the male only enters the cavity to feed the female. Following hatching, the female broods the young for up to 11 days, with both adults contributing to feeding the chicks (2) (7). The young leave the nest at about 18 days, but stay on the breeding territory for another two weeks (4) (7).

Although this species inhabits boreal forest throughout the year, in some parts of its range it may undertake short-distance movements in response to localised food shortages (4).

Habitat modification and habitat destruction due to logging are the primary threats to the boreal chickadee (2) (3) (4). In eastern regions of the boreal chickadee’s range, ‘salvage-cutting’ to remove dead and damaged trees in forests infested by budworm (a serious insect pest of spruce) has reduced much of the suitable habitat for this species (3).

As the population of the boreal chickadee is considered reasonably secure, there are currently no specific conservation measures targeted at this species. Much of the boreal chickadee’s range is fairly remote and relatively free from widespread logging, while its ability to inhabit both mature and young coniferous forest has made it less vulnerable to some of the negative impacts of logging in boreal forests (2) (3) (4).

Further research on the life history of the boreal chickadee is required, as are detailed population monitoring surveys to assess the effects of habitat loss on this species (2) (3).

Find out more about the boreal chickadee:

• Boreal Songbird Initiative:
  http://www.borealbirds.org/birdguide/bd0644_species.shtml
• BirdLife International:
  http://www.birdlife.org/