The Bewick's wren (Thryomanes bewickii) is a small passerine bird native to North America. Depending on geographic location, these birds differ in appearance; Eastern populations, prior to their decline, were described as being more colorful, Pacific populations are darker in appearance, while populations in the Southwest have grayer plumage. Geographic differences have also been noted in the song of Bewick's wrens. Each regional population of Bewick's wrens has distinctive vocalizations, in particular their call notes. Pacific populations sing notably more complicated songs than Southwestern populations. Eastern populations were also noted to be excellent singers.
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DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
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CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
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InsectivoresAn insectivore is a carnivorous plant or animal that eats insects. An alternative term is entomophage, which also refers to the human practice of e...
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ArborealArboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some anima...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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TerritorialA territory is a sociographical area that which an animal consistently defends against the conspecific competition (or, occasionally, against anima...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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AltricialAltricial animals are those species whose newly hatched or born young are relatively immobile. They lack hair or down, are not able to obtain food ...
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GlidingGliding flight is heavier-than-air flight without the use of thrust and is employed by gliding animals. Birds in particular use gliding flight to m...
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MonogamyMonogamy is a form of relationship in which both the male and the female has only one partner. This pair may cohabitate in an area or territory for...
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Partial MigrantPartial migration is when within a migratory species or even within a single population, some individuals migrate while others do not.
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starts withThe plumage of Bewick’s wrens is brown on top and light grey underneath, with a white stripe above each eye. Their beaks are long, slender, and slightly curved. The most distinctive feature of these birds is their long tails with black bars and white corners. They move their tails around frequently, making this feature even more obvious for observers. Juveniles look similar to adults, with only a few key differences. Their beaks are usually shorter and stockier. In addition, their underbelly might feature some faint speckling. Males and females are very similar in appearance.
Bewick's wrens are now found along the Pacific Coast from Baja California to British Columbia, in Mexico, and in a significant portion of the Southwest, including Texas, Arizona, New Mexico, and Oklahoma. They are now extremely rare east of the Mississippi River. Western populations do not tend to migrate. Eastern populations, prior to their decline, used to migrate from their northern range to the Gulf Coast. Bewick's wrens inhabit arid open woodlands and brush-filled areas such as hillsides and uplands, often near streams. In California, Bewick's wrens inhabit a shrubland area called chaparral.
During the breeding season, Bewick’s wrens spend time with their mates but go solitary throughout the winter. These birds are diurnal and spend days gleaning insects from vegetation, including the trunks of trees. They typically do not feed on vegetation higher than 3 meters, but they will forage on the ground. Bewick's wrens often hang upside down in order to catch an insect on the underside of a branch. When the bird catches an insect, it kills the prey before swallowing it whole. Bewick's wrens repeatedly wipe their beaks on the perch after a meal. They are very vocal. Both females and males make short calls while foraging and both use a harsh scolding call when agitated. Males also sing to attract mates and protect their territory. The song is broken into 2 or 3 individual parts; one individual male may exhibit up to 22 different variations on the song pattern, and may even throw in a little ventriloquism to vary it even further. A male wren learns its song from neighboring males, so its song will be different from its father's.
Bewick’s wrens are carnivores (insectivores). They eat mainly insects and insect eggs, spiders as well as larvae and pupae. In winter, they may supplement their diet with some fruit, seeds, and other plant matter. Bewick’s wrens also visit backyard feeders where they will eat suet, peanut hearts, hulled sunflower seeds, and mealworms.
Bewick’s wrens are monogamous and form pairs. Courtship begins with the male singing from its perch. It will occasionally pause its song in order to chase its competitors. The male starts building the nest in a cavity or birdhouse, with the female joining in later. The nest is constructed from twigs and other plant materials and is often lined with feathers. The nest is cup-shaped and located in a nook or cavity of some kind. The female lays 5 to 7 eggs, which are white with brown spots. The chicks hatch after 14-16 days; they are blind and naked at birth. The chicks will stay in the nest for about 14-17 days and will be fed by their parents for another 2 weeks. At about 5 weeks of age, they will disperse and will be able to breed at around 1-year-old. Bewick’s wrens can raise 1 to 3 broods in a season.
In 2016, the Bewick's wren was widespread due to the size of its range and estimates of its population size. However, ornithologists have noted a severe decline in its eastern range and parts of its western range. In particular, it has virtually disappeared from east of the Mississippi. It was suggested that the decline in its eastern range was caused by pesticide use and competition from other bird species. The most likely reason seems to be competition from House wrens. House wrens compete with Bewick's wrens for similar nesting sites and destroy both the nests and eggs of Bewick's wrens. The reforestation of once open land has also negatively impacted the eastern Bewick's wrens. In California, habitat loss due to development has impacted the Bewick's wren. In San Diego, the development of canyons has led to the gradual decline of native bird species, including the Bewick's wren.
According to IUCN Red List, the total population size of the Bewick’s wren is 7.9 million mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.
Due to their insectivorous diet, Bewick’s wrens control the populations of the insects they eat and thus control their numbers and keep the local habitat healthy. These small birds also serve as an important food source for local predators such as hawks.
