Rock Wren (Salpinctes obsoletus)

[order] PASSERIFORMES | [family] Troglodytidae | [latin] Salpinctes obsoletus | [UK] Rock Wren | [FR] Troglodyte de rocher | [DE] Felsen-Zaunkonig | [ES] Charralero de las Rocas | [NL] Rotswinterkoning

A gray wren of the rocks; has a finely streaked breast, light belly, rusty rump, buffy tail corners.

North America, Middle America : Southwest Canada to Costa Rica

Rocky slopes, canyons. Breeds from low canyons to hi
gh in mountains, wherever surroundings are very arid and rocky, but seldom in hottest desert regions. Winters in rocky places at low elevations; sometimes on rock levees, riprap below dams. In the absence of rocks it may establish winter territory around
stacks of hay bales, pieces of farm equipment, or other landmarks.

Nesting behavior is not well known. Male sings to defend nesting territory.
Nest: Site is usually in crevice among boulders, in hole in dirt bank, under a rock ledge, in crevice in stone building, or similarly sheltered site; rarely in low tree cavity. Nes
t (probably built by both sexes) is cup of grass, weeds, bark strips, twigs, rootlets, lined with finer materials such as animal hair, spider webs, feathers. Often marked by “paving” of small stones, sometimes with bones and other debris, laid out on grou
nd in front of the entrance to the cranny where the nest is located.
Eggs: 5-6, sometimes 4-8. White, lightly dotted with reddish brown. Incubation is probably by female; incubation period not well known.
Young: Both parents bring food for nestlings. Age at which young leave the nest is not well known.

Mostly insects. Diet is not well known. Probably feeds mostly on insects, including beetles, ants, grasshoppers, and many others, also spiders and probably other arthropods.
Behavior:
Forages on the ground in dry places, and on steep dirt banks and rocky cliffs with many cracks and openings. Uses long bill to probe in crevices among rocks. Sometimes forages among tangles of low vegetation or low on trunks of trees.

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Southwestern Canada, western United States to Costa Rica. Migration: Strongly migratory, departing from northern part of range for the winter. Strays sometimes wander east in fall and have even reached the Atlantic Coast.