American treecreeper
The Brown creeper (Certhia americana) is a tiny songbird associated with the biggest trees it can find. It looks like a piece of bark that has come to life: this bird crawls up tree trunks, foraging for insect eggs and other food missed by more active birds. Easily overlooked, its thin, reedy, piercing call indicates its presence. Reaching the top of a tree, it flutters to the base of the next, to begin spiraling its way up again.
Adult Brown keepers are brown on the upper parts with light spotting, resembling a piece of tree bark, with white underparts. They have a long thin bill with a slight downward curve and a long stiff tail used for support as the bird creeps upwards. The male creeper has a slightly larger bill than the female. Brown creepers are smaller than white-breasted nuthatches but larger than golden-crowned kinglets.
Brown creepers live throughout North America, from northern Nicaragua up to Canada, Alaska, and Newfoundland. In most of the range, it is resident, but populations in the north migrate southwards in winter, apart from high mountain regions. Brown creepers breed in coniferous or mixed forest areas. They need large trees, alive or dead, for nesting and foraging.
Brown creepers are diurnal and active birds that usually fly short distances between trees. They are usually seen alone outside the breeding season, though sometimes they may join a foraging flock of songbirds. Communal roosting may take place during winter. Brown creepers forage on tree trunks and branches, typically spiraling upwards from the bottom of a tree trunk, and then flying down to the bottom of another tree. They creep slowly with their body flattened against the bark, probing with their beak for insects. They will rarely feed on the ground. When alarmed, Brown creepers use their super camouflage pattern, landing on a tree trunk, flattening their body, and spreading their wings. When remaining motionless, they look just like bark. Brown creepers communicate mainly through vocalizations. When fighting for territory, males will sing a high-pitched song. Males also use vocalizations during the breeding season, making high and thin sounds that vary within a population.
Brown creepers are carnivores (insectivores). They mainly eat small arthropods found in the bark but sometimes will eat seeds in winter.
A Brown creeper is serially monogamous and a pair remains together for several weeks after fledging. The male uses his songs when attracting a mate. Then the male and female chase each other, fluttering rapidly while displaying their white underparts. These birds breed from mid-May until mid-June. Their nesting site is chosen by the pair, but the female builds the nest, with the male sometimes bringing her nest material. The nest is 5 to 15 feet from the ground and is often situated between the trunk of a dead tree and some loose bark, or in a natural cavity. 3 to 7 creamy or white eggs are laid, having fine, small, brown dots. Incubation is for 13 to 17 days, starting when the last egg has been laid. Only the female incubates, but the male feeds her at this time. The female broods the altricial chicks during bad weather, and both the parents feed them. Young fledge at around 15 to 17 days, but their parents feed them for 15 more days at least. They reach maturity at around one year of age.
Brown creeper populations are listed as threatened or endangered in several states, being threatened by habitat loss as well as degradation of the population’s breeding range, and the disappearance of large wooded regions.
According to the IUCN Red List, the total population size of the Brow creeper is 11 million mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are increasing.
