Boreal Chickadee

The State of Boreal Chickadees

Regionally: Steadily increasing

The mean (thick, dark brown 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 720 Mountain Birdwatch sampling stations north of 43.5 degrees latitude (the southern extend of breeding for Boreal Chickadee in the northeastern U.S). The lighter vertical bars represent the 95% Bayesian credible interval (a measure of the uncertainty around the abundance estimates).

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 been gradually increasing since 2010 at a mean annual rate of 2.52% (95% Bayesian credible interval [BCI] = -1.26% to 6.82%). The North American Breeding Bird Survey results also support these trends over the last decade, specifically, but Boreal Chickadee numbers have overall declined by >50% since the 1970s in our Northern Atlantic Forest bird conservation region.

Globally: 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. Available data, though, suggest that populations of Boreal Chickadees have broadly declined, since the late 1960s, across most of the United States and Canada with the exception of Alaska and northwest Canada.

Boreal Chickadee habitat is at risk of disappearance due to climate change. Recent climate modeling by Audubon, 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). Notably, 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 (see orange plot below).

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