Pacific Wren

The Winter Wren (Troglodytes troglodytes) was split into three species, with T. pacificus (Pacific Wren) and T. hiemalis (Winter Wren) being the two North American species. Troglodytes is an Old World wren. A superb songster and more often heard than seen, this small, brown wren is found along the pacific coast of N. America from Alaska south to the mid California coast. It is also found in the interiors of B.C., Washington, Oregon, California, Idaho and Montana.

Adult Male (spring/summer)

Overall dark brown plumage and short but well-defined supercilium is distinctive. Pale brown throat and heavily barred dark flanks, wings and tail.

Adult Female (spring/summer)

Sexes similar.

Juvenile

Dark brown overall but dark barring is less conspicuous.

General:

Tiny, short-tailed, and thin-billed wren. Length: 10 cm. Wing: 14cm. Weight: 9 g.

Behaviour:

This tiny species usually keeps its tail cocked up and has a habit of almost continually bobbing its head. It creeps mouse like about woodpiles and brush heaps, edges of swamps, on conifer stumps and through ferns searching for insects. It is a curious bird and is easily ‘pished’ out of the undergrowth. It sings loudly from favorite perches.

Habitat:

This species is unique among North American wrens in its association with old-growth forests. It uses old-growth structures (snags, downed logs, and large trees) for nesting, foraging and roosting. It can also be found in mixed deciduous-conifer forests.

Information:

The song of the Pacific Wren is a loud, rich, liquid and full song with rising and falling high-pitched notes in a fine silver thread of music lasting about seven seconds and containing 108-113 separate notes. It sings from a low perch or on the ground.

Pacific Wren nests, made of mosses, grasses and twigs and lined with hair and feathers are placed under roofs, in rock crevices, in stumps, stream banks, natural cavities and nest boxes. The number of eggs laid are from four to seven and are white with brown spots.

Similar species:

House Wren, Marsh Wren.

Conservation Status:

Clearcutting and some types of partial logging reduce habitat suitability and this species is one of a few clearly harmed by forest fragmentation in western North America.

Preferring the forested areas of the perimeter of Colony Farm, Pacific Wren capture occurs minimally in April, June and July. Juvenile dispersal is reflected by peak capture rates in September and October.

Molt Summary:

PF: HY partial-incomplete; PB: AHY complete; PA absent
Preformative molt includes 4 – 10 inner gr covs, usually 1 – 3 terts (occasionally s6 as well), and occasionally
1 – 2 central rects (r1)
Molt limits can be difficult to see (usually among gr covs) thus many intermediates (esp. Apr-Jul) difficult / impossible to age reliably.