A combination of the shape and structure of this species, as well as its drab brown colouration and typical rocky habitat render it nearly unmistakable within B.C. The only other remotely similar species inhabiting similar habitats, the Canyon Wren, is noticeably darker and richer chestnut-brown with a sharply contrasting white throat and breast. These two species should not be easily confused.
| The male’s song consists of a jangling, ringing series of phrases of 3-5 repeated notes, with the notes within each phrase changing and pauses of several seconds between each phrase: keree-keree-keree, tweer-tweer-tweer-tweer, chrr-chrr-chrr, prree-prree-prree. The call note, which is given by both sexes, is an emphatic, ringing, two-noted tick-ear, usually produced by the bird during a deep, exaggerated bob. Source: Lowther et al. (2000). | Courtship The male’s song functions as the primary means of courtship in Rock Wren, although courtship-feeding has also been observed. During singing, the male typically sings from a high, exposed rock outcrop within his territory or from within vegetation to a height of 6 m. This species is monogamous throughout the breeding season.
Nest Nest building begins early, shortly after arrival on the breeding grounds. Both sexes participate in the construction process, which takes 3-5 days to complete. The nest itself is usually placed in a cavity or a sheltered, secluded location such as beneath an overhanging rock, within a crack in loose talus, or in a crevice in a cliff or rock face. This species sometimes places its nest in subterranean mammal burrows (e.g., ground-squirrels) or in crevices in buildings or structures (e.g., dams). The nest is a shallow cup ~9 cm across. It is composed of grass, sticks, strips of bark, moss, hair, and occasionally fresh plant material and is lined with rootlets, hair, wool, and spider silk. It is typically situated on a foundation of stone and may contain tiny pebbles in the lining. The Rock Wren has an unusual habit of often constructing a narrow “pathway” or “pavement” of stones and other material (small bones, feathers, small bits of garbage, twigs) leading up to the edge of the nest.
Eggs Clutches of late (4) 5-6 (10) eggs are laid following nest completion. In B.C., eggs have been documented between late April and late July, although May is likely the primary month for eggs in the province. The eggs are smooth, glossy, and whitish with sparse, fine reddish-brown to buffy-brown or pale purplish speckling and blotches. The incubation period is 12-15 days, and most eggs likely hatch between late May and mid-June. Only the female incubates the eggs, often fed by the male. This species appears to be double-brooded in B.C., producing two clutches in some areas. This species is an occasional host for Brown-headed Cowbird parasitism, but this has not been recorded in B.C.
Young Young may appear in B.C. as early as late May, but most likely appear in June and July. After hatching, the hatchlings remain in the nest for 14-16 days before fledging and are tended by both parents. The altricial young have pale pinkish skin and patches of yellowish-white down; the mouth is pinkish-yellow. Once they have left the nest they continue to follow the female around the territory as a “family group” before becoming independent. Parental care of late broods has been recorded in B.C. into August and even early September.
Source: Baicich and Harrison (1997); Campbell et al. (1997); Lowther et al. (2000).
| The Rock Wren feeds primarily on insects and other arthropods such as grasshoppers, crickets, ants, aphids, leafhoppers, beetles, and spiders, and is known to occasionally consume small lizards. It hunts primarily along the ground and on the surfaces of rocks and boulders, commonly entering cracks or crevices in loose rock or probing into clumps of grass in search of prey. It generally picks prey directly from the substrate and rarely captures insects in flight. It occasionally consumes aquatic insects such as dragonfly larvae, and has been known to forage in a creeper-like fashion along the bark of trees.
Source: Lowther et al. (2000).
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