The Bewick’s Wren (pronounced buick’s) is present year round in much of western and south-central US and, much of the Baja peninsula and Mexico. It is also a year round resident of southwestern BC. It has all but disappeared east of the Mississippi River.
Adult Male (spring/summer)
Crown brown; white supercilium; buffy supraloral stripe; brown eye stripe; auriculars pale brown with gray-white speckles. Chin and breast white; belly gray; lower flanks buffy and undertail coverts barred. Nape, mantle and rump brown; wings brown with black barring; long tail brown with black barring and white tips on outer retrices. Bill is long and down curved.
General:
A slender, long necked and long tailed wren. Length: 13cm. Wing: 18cm. Weight: 10grams.
Behaviour:
The Bewick’s Wren is quite often first recognized by its far-carrying song or buzzy scold notes. It forages low or on the ground in thickets and undergrowth for insects and fruit. Flight when flushed is short and erratic on rounded wings.
Habitat:
The Bewick’s Wren is found in dry brushy habitats and thickets of open country and in open woodlands near rivers and streams. In urban areas; parks, farmland and open woods. They cock their tails over their backs in typical wren fashion and during breeding season sing vigorously from prominent perches.
Information:
This is the only species of its genus Thryomanes. Interestingly, it is named for Thomas Bewick a north England ornithologist, bird illustrator and wood engraver, even though the bird is not found in Britain or Europe. The Bewick’s Wren is present year round in the Vancouver area and is a fairly common resident, though easily overlooked because of its skulking nature. It nests in cavities or in dense brush piles, and will utilize old woodpecker holes, knotholes in fallen trees, and bird boxes. The nest is of leaves, straw and other debris and lined with feathers or other soft material. 3-8 white with reddish-brown or purplish spotted eggs is laid. The song is variable with opening notes high, followed by lower burry notes and ending on a thin trill, frequently like swee, swee, cheeeeee, somewhat reminiscent of a Song Sparrow. There is considerable regional variation in its song. Plumage is varied with the upperparts of eastern birds being overall richer brown and those of the southwestern US much more grey.
Similar species:
Conservation Status:
Although the conservation status of Bewick’s Wren is listed as Least Concern there has been severe declines of the species in the eastern United States. It is suspected that the House Wren, which frequently removes eggs from nests in cavities, has been directly responsible for the decline. The increased availability of nest boxes may have helped the spread of the House Wren, and consequently the decline of the Bewick’s Wren.
Capture Rates
As a resident species with two broods a possibility, capture rates of Bewick’s Wren span spring through fall when the birds are most active and peak in July/August then again in October reflecting juvenile dispersal.
Molt Summary:
PF: HY partial – incomplete, PB: AHY complete; PA absent
Preformative molt is variable, sometimes eccentric, with outermost 4 – 7 pp and the innermost 3 – 6 ss, but usually no pp covs replaced. Others replace 6 – 10 inner gr covs and 1 – 3 terts (s6 in some birds) but no pp. Rects vary from none to all replaced.
Molt limits are hard to detect.
Although ageing BEWR can be extremely difficult separating adults (AHY/ASY) from juvenal (HY) birds is relatively easy.
HY birds in the summer months have generally paler plumages, more loosely textured feathers (particularly nape and undertail coverts), prominent gapes and the supercilium is less well defined and buffy not whitish as in these four examples of HY birds in August.
The two photos below show the wing and tail of a HY in July in fresh juvenal plumage.
The two photos immediately below show adult (AHY) birds in spring. Separating SY from ASY birds is extremely difficult as molt limits are hard to detect but adults (AHY) generally show uniformly adult flight feathers and wing coverts and truncate outer primary coverts. The supercilium of adult birds is also well defined, whitish and extends further towards the hindcrown.