Dull in appearance but notable for its effervescent song, the house wren is a common summer inhabitant of scrublands and woodland edges throughout much of North America. Variation in plumage and call notes is extensive. Polytypic. Length 4.7".
A small wren with medium-length bill and tail, it responds readily to pishing. Overall jizz is of a plain, typical wren. Adult: one molt a year; sexes similar. All populations brownish above, paler gray-brown or gray below. Supercilium, often indistinct, is paler than crown and auriculars. Juvenile: variable, but many differ from adults in having warmer buff and rufous tones, along with indistinct scalloping on throat and breast.
Two widespread, poorly differentiated subspecies in North America: Western parkmanii and eastern aedon. Eastern birds average more rufescent, western birds grayer. The cahooni subspecies, allied with Mexican brunneicollis (“brown-throated wren”), in mountains of southeastern Arizona, shows warmer tones to the throat and breast; supercilium more distinct. Twenty-nine subspecies (possibly involving multiple species) occur south of North America, ranging south to southern South America.
Main point of confusion is winter wren; it is smaller, shorter-tailed, more heavily barred on the flanks and crissum, and usually darker. Winter and house wrens further distinguished by differences in song, call, timing of migration, microhabitat preferences, and foraging behavior.
Most vocalizations have a “dry” quality. Call: most given singly or in stuttering series. A scratchy, frequently heard call is similar to that of the common yellowthroat. Another note, which is raspy, resembles that of the blue-gray gnatcatcher. Song: loud, bubbly. Starts hesitantly, quickly erupts into a cascade of down-slurred dry trills. Usually easy to recognize, but due to considerable variation may be confused with certain non-troglodytids (e.g., rufous-crowned sparrow).
Status and Distribution
Common. Breeding: most vegetated habitats, except for dense forests, open grassland, marshland, and desert. Favored microhabitats include clearings, edges, residential neighborhoods. Migration: most birds in North America migratory. Major spring movement follows that of the winter wren; major fall movement precedes that of the Winter. Winter: generally as breeding, but with greater tendency for dense cover. Not a hardy species; stragglers north of core wintering range uncommon. Vagrant: sometimes noted to offshore or peninsular locales from which otherwise absent.
Long-term population increases documented in many areas. Species is tolerant of humans and readily accepts nest boxes.
—From the National Geographic book Complete Birds of North America, 2006