The House wren (Troglodytes aedon) is a very small most widely distributed native bird in the Americas. It occurs in most suburban areas in its range and it is the single most common wren. The name troglodytes means "hole dweller", and is a reference to the bird's tendency to disappear into crevices when hunting insects or to seek shelter.
The coloration of this species varies greatly, with upperparts ranging from dull greyish-brown to rich rufescent-brown, and the underparts ranging from brown, over buff, and pale grey, to pure white. These birds have blackish barring to the wings and tail, and some also to the flanks. They show a faint eye-ring and eyebrow and have a long, thin bill with a blackish upper mandible, and a black-tipped yellowish or pale grey lower mandible. The legs are pinkish or grey. The short tail is typically held cocked.
House wrens occur from Canada to southernmost South America. North American birds are migratory spending winter in the southern United States and Mexico. House wrens live in a variety of habitats including open forests, woodlands, thickets, dense shrubs, tangles, grooves, orchards, and are, as indicated by their common name, often associated with humans.
House wrens are diurnal birds spending their day foraging actively in vegetation. They are usually seen alone, in pairs, or in small family groups and rarely attend mixed-species feeding flocks. House wrens are very famous for their rich bubbly song which is commonly heard during the nesting season but rarely afterward.
House wrens are carnivores (insectivores). They mainly eat insects such as butterfly larvae, beetles, grasshoppers, crickets, caterpillars, moths, flies and also take spiders and snails.
House wrens are monogamous and form pairs. Their breeding season usually occurs between late April and early September. They usually construct a large cup nest in various sorts of cavities, taking about a week to build. The nest is made from small dry sticks and is usually lined with a variety of different materials. These include feathers, hair, wool, spider cocoons, strips of bark, rootlets, moss, and trash. The male wren finds dry sticks, which he adds to the nest. Once he is done, the female inspects at the nest; but if she does not approve of the construction, she will throw any unwanted sticks to the ground. After this process, the female lines the nest. Nest cavities are usually a few meters above ground at most, but occasionally on cliffs as high up as 15 m (49 ft); they may be natural or man-made, often using birdhouses. The clutch usually consists of 2-8 red-blotched cream-white eggs. Only the female incubates these, for around 12-19 days. While she is on the nest, the male provisions her with food. The chicks hatch almost naked and helpless and take another 15-19 days or so to fledge. They will remain with their parents for another 2 weeks and attain reproductive maturity at 1 year of age.
House wrens are common and widespread throughout most of the Americas and are not considered threatened at present. However, populations in some northern parts of their range may have been displaced somewhat by the introduction of the House sparrow.
According to the All About Birds resource, the global breeding population of the House wren is 160 million individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List, and its numbers today are increasing.
