Chestnut-backed

Chickadee Poecile rufescens

Introduction

This chickadee, the most colourful of chickadees, can be found during the non-breeding season in flocks of other Chestnut-backed Chickadees and in mixed species flocks of Kinglets, Nuthatches, Creepers and Titmice. The conspicuous flocks move through the forest foraging together. It is resident in coastal regions of south-central Alaska southward along the Pacific Northwest coast and coastal islands to north-central California. There are inland populations in areas of BC, Washington, Montana, Oregon, Idaho and California.

Identification

Adult Male (spring/summer)
The cap from the forehead to bottom of the nape and just below the eyes is dark brown-black. The chin is black with a narrow white cheek. The back, rump and flanks are a deep chestnut brown. The sides and belly are dull grayish. The wings are brownish gray with whitish edging on the inner secondaries and greater coverts, which are also tipped with white. The tail is brownish gray with paler gray edgings. The bill is black, legs and feet are dark grey and the eyes are dark brown. Adult plumages are similar throughout the year.

Adult Female (spring/summer)

Females are slightly smaller but plumage is similar to that of the male.

Juvenile

Closely resembles adult.

General Information

General:

A small and short-tailed Chickadee with distinct chestnut-brown back.
Length: 12cm. Wing: 19cm. Weight: 9.7 grams.

Behaviour:

The Chestnut-backed Chickadee moves quickly while foraging for insects, berries and seeds taking them from twigs and branches. It sometimes hovers while taking food from above or below branches. It probes in crevices of bark and takes seed and suet from feeders. Chestnut-backed chickadees often travel in small flocks of four to twenty birds.

Habitat:

Occupies moist coniferous forest consisting of spruce, fir, tamarack, hemlock and cedars. In British Columbia it can also be found in mixed coniferous deciduous forests. In the southern part of its range it lives in oak woods, streamside willow groves, pine-oak woods as well as in redwood forest with an understory of alders and willows.

Information:

Unlike the familiar Black-capped Chickadee the Chestnut-backed lacks a whistled song.

In its very humid coastal belt, in wet forests of hemlock and tamarack this is the only chickadee present.

It is not known to migrate. In BC it is considered non-migratory but there is post-breeding dispersal to higher elevations in late summer and early autumn.

A cavity nester, the nest can be up to 80 feet high but is usually restricted to between 2 and 20 feet high. It may utilize vacant woodpecker cavities, nest boxes or tree cavities. The nest has a foundation of moss, lichens, and feathers, bark fibers, plant down, lined with soft materials such as animal hair. Six to seven white eggs with reddish brown dots are laid.

Similar species:

Black-capped Chickadee, Boreal Chickadee, Mountain Chickadee.

Conservation Status:

Listed as Least Concern.

Maps & Statistics

Capture Rates

Although a year-round resident , the Chestnut-backed Chickadee can exhibit seasonal movements where during the summer months, it moves to higher elevations. This, along with the fact that they prefer dense, wet coniferous forests make this chickadee a rare visitor to our banding station peaking in March/April then appearing again in September, skipping the summer months altogether.

Ageing and Sexing (Band Size: 0)

Molt Summary:

PF: HY partial, PB: AHY complete; PA absent
Preformative molt includes 6 – 10 inner gr covs, but no terts or rects

Beware colour contrasts (pseudolimits) within the greater coverts in this species (see below).

See also Black-capped Chickadee account.

HY/SY

September - August

This SY in March is showing a molt limit within the greater coverts, the retained outer coverts (red arrow) with little or no edging compared to the distinctly whitish edged replaced inner coverts.

Care should be taken when when looking for molt limits in Chickadees to make sure we are not misled by the pseudolimit mentioned in the molt summary above which is the result of a natural colour contrast within the inner greater coverts and can simulate a molt limit but is NOT the result of feather replacement. However, in the case of this bird, the molt limit among the outer greater coverts is real with the outermost feathers being retained juvenal feathers and the inner visible feathers being replaced feathers.

While the colour does fade a bit distally (outwards) on the wing, the outer greater coverts, and for that matter the retained carpal covert, aula, and primary coverts, are identified as retained feathers because of their much more washed out, worn, and lightly pigmented appearance. Retained feathers on members of the tit family (Paridae) will sometimes (but not always) be longer than the replaced ones – the step down (or out) visible here.

This SY in March had replaced only two middle greater coverts (GCs 4 & 5) forming two steps out between replaced and retained feathers (red lines).

Notice again the washed out, worn, and lightly pigmented appearance of the retained outer greater coverts, carpal covert, aula, and primary coverts.

Tail shape is another helpful clue to ageing birds in the hand. It is important not to use tail shape alone as it is generally not very reliable because of a) individual variation and b) the possibility of accidental loss and replacement (called adventitious molt) which is another way in which Chickadees confuse as they often lose and replace tail feathers.

The rectrices in the photo below show a second year (SY) bird in March (the tail of the bird in the photo immediately above). They are more tapered (pointed) than adult rectrices, have little or no white edging and the white doesn’t wrap around on to the inner web of those feathers. Notice also the amount of wear to these feathers – retained juvenal feathers which are poor quality and weaker structured are more prone to wear than adult feathers.

Feather exposure to sun and abrasion is the major cause of feather deterioration and is especially hard on juvenal feathers. Exposure wears down feathers both through structural weakening and break-down as a result of solar irradiation, and through physical abrasion against foliage and the ground. Because juvenal feathers are of poor quality, they tend to wear down and fade more rapidly than subsequently grown feathers.