Boreal Chickadee

The State of Boreal Chickadees

Regionally: Steadily increasing

Boreal Chickadee study area abundance from 2010 to 2023.

The mean (thick, dark line) annual estimate of Boreal Chickadee abundance—calculated as the annual sum of estimated Boreal Chickadee within the local area (a 4-hectare circle) surrounding all 791 Mountain Birdwatch sampling stations. The thinner, lighter lines represent less probable estimates of the annual abundance.

In our region, sizable populations of Boreal Chickadees only occur in Maine, New Hampshire, and the Adirondacks of New York. Mountain Birdwatch data suggest that Boreal Chickadee populations in the northeastern United States have likely been gradually increasing since 2010 at a mean annual rate of 3.29% (80% Bayesian credible interval [CRI] = 0.66% to 6.05%).

Globally: Slightly Declining

Because they occupy remote areas without road access, and because they tend to be quiet and secretive during the breeding season, Boreal Chickadees are not well-monitored by the Breeding Bird Survey. Keeping that in mind, the Breeding Bird Survey data suggest slight declines over the last 50 years in the Eastern U.S., and stable populations in much of Canada. Conversely, eBird trends suggest steady (and in some cases substantial) declines across the southern portion of the Boreal Chickadee breeding range.

Boreal Chickadee habitat is at risk of disappearance due to climate change. Recent climate modeling predicts that >50% of the current range of Boreal Chickadees will be lost over the next 100 years as temperatures increase. By the end of this century, it is probable that Boreal Chickadees will no longer occur in the lower 48 states.

The Hivernant: Boreal Chickadees (Poecile hudsonicus) are one of the few hardy songbirds that reside year-round in the boreal forest. Many elements of their natural history – storing food, for example – reflect the attributes needed to survive through the harsh winters in this forest biome.

Range and habitat

The year-round range (pastel green) of Boreal Chickadee extends across the boreal forest of Canada and Alaska and the northernmost forests of the lower 48 United States.

Boreal chickadees are year-round residents of the boreal forest of Canada, Alaska, and the northernmost parts of the Pacific Northwest, the Lake States, and New York and northern New England. In the northeastern United States, they occur in both lowland (mostly in Maine) and mid-elevation montane forests of spruce and fir (see blue plot below). Historical records indicate that this species likely bred more extensively and further south (at least Pennsylvania) than currently. The Catskills currently lack a breeding population of Boreal Chickadees, and Boreal Chickadees are only known to breed in the Northeast Kingdom within Vermont. Within Vermont, Boreal Chickadees are only detected from Mountain Birdwatch surveys on the East Mountain route. Although they are resident in the Adirondacks and White Mountains, Boreal Chickadees do not reliably occur in the spruce-fir forests of the Green Mountains.

The mean relationship between abundance and elevation (dark blue line) of Boreal Chickadees within the Mountain Birdwatch study area and the uncertainty of those estimates (i.e., the 95% Bayesian credible interval, represented by thin lines). (Click to enlarge).

The mean relationship between abundance and latitude (dark green line) of Boreal Chickadees within the Mountain Birdwatch study area and the uncertainty of those estimates (i.e., the 95% Bayesian credible interval, represented by thin lines). (Click to enlarge).

The mean relationship between abundance and longitude (dark orange line) of Black-capped Chickadees within the Mountain Birdwatch study area and the uncertainty of those estimates (i.e., the 95% Bayesian credible interval, represented by thin lines). (Click to enlarge).

Although Boreal Chickadees do not regularly migrate outside of their breeding range, they do undertake periodic southward movements – known as ‘irruptions’. Irruptions happen most often in the fall, and may consist largely of hatch-year birds wandering in search of food. Irruptions of Boreal Chickadees tend to coincide with irruptions of Black-capped Chickadees. Boreal Chickadees are also altitudinal migrants, making seasonal (or shorter) elevational adjustments to take advantage of locally abundant food or to eschew poor weather.

More Natural History