Distinguishing Features
The Canyon Wren is a small, energetic
and inquisitive bird. The bill is relatively long, slender and slightly
downcurved. The top of head, nape and upper back is greyish brown
with chestnut on the lower back and rump. The upper parts are dotted
with black and white. Tail is rusty with narrow bars of black. Throat
and upper breast are white. Total length is 13 -15 cm (Godfrey,
1986).
Distribution
Columbia Basin: A small breeding
population exists in the arid parts of the Columbia River near Castlegar
(Campbell et al. 1997).
British Columbia: Very small range
with the bulk of the population restricted to the Okanagan Valley
south of Naramata. Occasional records exist from as far north as
Kamloops and as far west as Hedley in the Similkameen Valley (Cannings
et al. In prep.).
Global: Resident from sc. British
Columbia, Idaho, s. Montana south through the w. United States west
of c. Wyoming, c. Colorado, wc. Texas to the interior of Mexico
from Sonora and Nuevo Leon as far south as Oaxaca (Cannings et al.
In prep.).
Habitat
Canyon walls, cliff faces and rockslides.
Canyon Wrens in North America are restricted to arid, rocky habitats
within a wide variety of plant communities ranging from deserts,
grasslands, and shrub-steppe, to forests of oak, redwood, ponderosa
pine, and Douglas fir. Physical features of the landscape narrowly
define suitable habitat. Towering rock canyons, fractured cliffs,
large blocky talus, and rock outcrops provide the nooks and crannies
used for nesting, feeding, thermal cover, and security. (Godfrey,
1986., Cannings et al. In prep.).
Threats
Although populations can crash in
response to severe winters, they are able to recover fairly rapidly,
probably due to post-breeding dispersal behaviour (Campbell et al.
1997). British Columbia's population is highly variable, but without
a clear long-term trend. Although local breeding sites are susceptible
to human disturbance such as rock climbing, and destruction by industrial
activities, Canyon Wrens are relatively safe from most development
pressures, although removal of talus for landscaping and fill has
been recently identified as a threat (Cannings et al. In prep.)
Biology
Canyon Wrens are opportunistic insectivores,
feeding on a wide variety of spiders, beetles, and other insects.
Using their long slender bill and flattened head, they are able
to probe deeply under rocks and into narrow rock crevices to glean
prey. They spend most of their foraging time in concealed situations
amongst talus and within rocky crevices. A cup nest of twigs, grasses,
and moss, lined with lichens, plant down, cobwebs, and feathers
is constructed in a small cave, rock crevice, or ledge with a protective
shelf above it, and is typically maintained from year to year (Cannings
et al. In prep.).
Clutches of 4 - 6 eggs are laid between late April
and early July, and two broods are often attempted. Incubation by
the female lasts around 16 days, and the young remain in the nest
for approximately 15 days after hatching (Cannings et al. In prep.).
