A medium-sized (5 ¼ inches) wren, Bewick’s Wren is most easily identified by its plain brown back, pale breast, long tail (often held up at an angle), long curved bill, and conspicuous white eye-stripes. This species may be distinguished from the similar House Wren (Troglodytes aedon) by that species’ small size and fainter eye-ring and from the Carolina Wren (Thryothorus ludovicianus) by that species’ larger size and warmer-toned plumage. Male and female Bewick’s Wrens are similar to one another in all seasons. Bewick’s Wren primarily occurs in western North America from British Columbia south to central Mexico and east to the central Great Plains. Although this species was formerly widespread in the eastern United States as far north and east as the Mid-Atlantic region, its range in those areas is greatly reduced today compared to a century ago, with isolated pockets persisting in the Ohio River valley and the southern Appalachian Mountains. In this species’ core range, most birds are non-migratory, although some birds at the northern or southern extremities of this range migrate short distances south in winter. Bewick’s Wrens inhabit open areas with thick ground cover, such as bushy fields, thickets, and dry scrubland. Eastern populations are heavily dependent on land cleared for agriculture, and much of this species’ decline in those areas is thought to have been caused by the return of woodland habitats to its favored abandoned agricultural fields. Bewick’s Wrens primarily eat small insects, but may also eat small quantities of seeds and berries during the winter when insects are scarce. In appropriate habitat, Bewick’s Wrens may be seen foraging for food on the ground or in the branches of bushes and shrubs. Birdwatchers may also listen for this species’ song, a series of buzzing notes recalling that of the Song Sparrow (Melospiza melodia). Bewick’s Wrens are most active during the day.
Bewick’s wren (Thryomanes bewickii), is a common North American perching bird in the order Passeriformes and the family Troglodytidae.This species is native to Canada, Mexico, and the United States and is located mainly from southwest British Columbia through the western and south-central United States, and deep into central Mexico, with rare appearances in the eastern United States (Birdlife International 2016).Due to its large geographic range, it can be found in diverse habitats such as thickets, underbrush, gardens, streamside groves, rivers, chaparral-covered hillsides, desert washes, and suburban areas (Kaufmann 2018).
This small bird has a distinctive bold white line that extends over the eye to the back of the neck and also has white spots on the tail.It features a slender body with a long tail, grey or whitish belly, and brown to greyish brown back.The average length is 13 cm, but males are slightly larger than females, with a wing length of 58.2 mm and 55.6 mm respectively.It has an average weight of 10-11 g, which is similar to other North American wrens (Kennedy and White 2013).
Bewick’s wrens are highly active, often hopping about in the trees within 10 feet of the ground, or beelining to their next destination when they leave their vegetative cover. They forage both by probing tree bark and searching through leaf litter on the ground. Their diet consists mainly of small invertebrates, namely grasshoppers, beetles, wasps, spiders, bugs, moths, and caterpillars, but also includes seeds and fruit. When they catch their prey, they crush it or shake it to death before swallowing it whole. They are usually solitary foragers until mating season, but some pair bonds persist throughout the year, possibly to prevent the partner from mating with another bird. Though many stay in one place all year, some migrate from northern areas and higher elevations in winter. Those that inhabit eastern regions may be more prone to migration than those from the west (All About Birds 2018; Kaufmann 2018; Seattle Audubon 2018).
Mating songs of T. bewickii are done by males only. The melodious territorial song consists of 3-5 phrases with 1-2 trills, performed with a markedly vigorous rhythm. Clutches are started over a long period, beginning in mid-March in Oklahoma and early April in Kansas and Oregon. Females lay 1 egg per day until the clutch is complete, which typically consists of 5-7 eggs, but sometimes as many as 11. The young hatch about 14 days after the laying of the penultimate egg, and the earliest hatching dates are late March/early April in southern populations and late April/early May in northern populations (Kennedy and White 2013). The oldest recorded Bewick’s wren was at least 8 years old when it was recaptured and released in 1986 (All About Birds 2016).
Predators of the Bewick’s wren include the black rat snake, Great Plains rat snake, and eastern milk snake, which prey on the eggs and nestlings, while sharp-shinned hawks, greater roadrunners, and rattlesnakes prey on adults.There is also much competition between other species of wrens and some will remove eggs or kill nestlings.With few predators and an extremely large and stable population this species is considered of least concern by the IUCN (Bird Life International 2016).However, some populations within the United States are at a risk, particularly in the eastern United States, where they have mostly disappeared, possibly due to the expansion of house wrens and other competitors (Kennedy and White 2013; Seattle Audubon 2018).
A medium-sized (5 ¼ inches) wren, Bewick’s Wren is most easily identified by its plain brown back, pale breast, long tail (often held up at an angle), long curved bill, and conspicuous white eye-stripes. This species may be distinguished from the similar House Wren (Troglodytes aedon) by that species’ small size and fainter eye-ring and from the Carolina Wren (Thryothorus ludovicianus) by that species’ larger size and warmer-toned plumage. Male and female Bewick’s Wrens are similar to one another in all seasons. Bewick’s Wren primarily occurs in western North America from British Columbia south to central Mexico and east to the central Great Plains. Although this species was formerly widespread in the eastern United States as far north and east as the Mid-Atlantic region, its range in those areas is greatly reduced today compared to a century ago, with isolated pockets persisting in the Ohio River valley and the southern Appalachian Mountains. In this species’ core range, most birds are non-migratory, although some birds at the northern or southern extremities of this range migrate short distances south in winter. Bewick’s Wrens inhabit open areas with thick ground cover, such as bushy fields, thickets, and dry scrubland. Eastern populations are heavily dependent on land cleared for agriculture, and much of this species’ decline in those areas is thought to have been caused by the return of woodland habitats to its favored abandoned agricultural fields. Bewick’s Wrens primarily eat small insects, but may also eat small quantities of seeds and berries during the winter when insects are scarce. In appropriate habitat, Bewick’s Wrens may be seen foraging for food on the ground or in the branches of bushes and shrubs. Birdwatchers may also listen for this species’ song, a series of buzzing notes recalling that of the Song Sparrow (Melospiza melodia). Bewick’s Wrens are most active during the day.
The Bewick's wren (Thryomanes bewickii) is a wren native to North America. It is the only species placed in the genus Thryomanes. At about 14 cm (5.5 in) long, it is grey-brown above, white below, with a long white eyebrow. While similar in appearance to the Carolina wren, it has a long tail that is tipped in white. The song is loud and melodious, much like the song of other wrens. It lives in thickets, brush piles and hedgerows, open woodlands and scrubby areas, often near streams. It eats insects and spiders, which it gleans from vegetation or finds on the ground.[2]
Its historic range was from southern British Columbia, Nebraska, southern Ontario, and southwestern Pennsylvania, Maryland, south to Mexico, Arkansas and the northern Gulf States. However, it is now extremely rare east of the Mississippi River.[3]
In 1827 the American ornithologist John James Audubon included an illustration of Bewick's wren under the binomial name Troglodytes bewickii in his The Birds of America.[4] In the companion Ornithological Biography, published four years later, Audubon explained that he had shot the specimen near St. Francisville, Louisiana in 1821 and had chosen the specific epithet bewickii in honour of his friend the engraver Thomas Bewick.[5] Bewick's wren is now the only species placed in the genus Thryomanes that was introduced by the English zoologist Philip Sclater in 1862.[6][7]
The Socorro wren was formerly also placed in Thryomanes, but is now known to be a close relative of the house wren complex, as indicated by biogeography and mtDNA NADH dehydrogenase subunit 2 sequence analysis, whereas Thryomanes seems not too distant from the Carolina wren.[8]
Fifteen subspecies are recognised of which two are now extinct.[7] Subspecies can be distinguished by the small differences in the color of the dorsal feathers but this can be difficult for museum specimens as the colors tend to change after a few years of storage.[9]
The Bewick's wren has an average length of 5.1 inches (13 cm) an average weight of 0.3 to 0.4 ounces (8 -12 g), and a wingspan of 18 cm.[10] Its plumage is brown on top and light grey underneath, with a white stripe above each eye. Its beak is long, slender, and slightly curved.[2] Its most distinctive feature is its long tail with black bars and white corners. It moves its tail around frequently, making this feature even more obvious for observers.[11]
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.[2] Males and females are very similar in appearance.[2]
Bewick's wrens, like many wrens, are very vocal. Both females and males make short calls while foraging and both use a harsh scolding call when agitated.[2] Males also sing in order to attract mates and protect their territory.[2] The song is broken into two or three individual parts; one individual male may exhibit up to twenty-two different variations on the song pattern, and may even throw in a little ventriloquism to vary it even further.[12] A male wren learns its song from neighboring males, so its song will be different from its father's.[2]
Geographic differences have been observed in the appearance of the Bewick's wren. Eastern populations, prior to their decline, were described as being more colorful, such as having a reddish tint to its brown feathers. Pacific populations are described as being darker in appearance, while populations in the Southwest are described as having a grayer plumage.[11]
Geographic differences have also been noted in the song of Bewick's wrens. Each regional population of Bewick's wrens have 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.[11]
The Bewick's wren once had a range that extended throughout much of the United States and Mexico and parts of Canada. It used to be fairly common in the Midwest and in the Appalachian Mountains, but it is now extremely rare east of the Mississippi River. It is still 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.[3] Western populations do not tend to migrate. Eastern populations, prior to their decline, used to migrate from its northern range to the Gulf Coast.[2]
The preferred habitat of the Bewick's wren is that of arid open woodlands and brush-filled areas such as hillsides and uplands, but will reside in humid areas locally (Subtropical and Temperate zones).[13] They are more common than house wrens in drier habitats, such as those found in the Southwest.[3] In California, Bewick's wrens inhabit a shrubland area called chaparral.[14]
Bewick's wrens are insect eaters. They glean insects and insect eggs 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.[3] Bewick's wrens are capable of hanging upside down in order to acquire food, such as catching an insect on the underside of a branch. When it catches an insect, it kills the insect prior to swallowing it whole. Bewick's wrens will repeatedly wipe their beaks on its perch after a meal.
Bewick's wrens will visit backyard feeders. They will eat suet, peanut hearts, hulled sunflower seeds, and mealworms.[15] Like many insect-eating birds, the Bewick's wren widens its diet to include seeds in the winter.[16]
Courtship begins with the male singing from its perch. It will occasionally pause its song in order to chase its competitors. Bewick's wrens form monogamous pairs that will then forage together.[2] The male wren begins 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. It lays 5–7 eggs, which are white with brown spots. The Bewick's wren produces two broods in a season. Pairs are more or less monogamous when it comes to breeding, but go solitary throughout the winter.[17]
In 2016, the Bewick's wren was listed as least concern on the IUCN Red List of threatened species due to the size of its range and estimates of its population size.[1] However, ornithologists have noted a severe decline in its eastern range and parts of its western range.[3] In particular, it has virtually disappeared from east of the Mississippi. In 1984, the state of Maryland classified the Bewick's wren as endangered under its Maryland Endangered Species Act of 1971. Despite this classification, no breeding pairs of Bewick's wrens are known to remain in Maryland.[18] In 2014, the North American Bird Conservation Initiative placed the eastern Bewick's wren on its watch list.[19]
Several theories have been proposed to explain its decline in its eastern range, including pesticide use and competition from other bird species.[3] The most likely reason seems to be competition from house wrens. House wrens compete with Bewick's wrens for similar nesting sites. House wrens will destroy both the nests and eggs of Bewick's wrens.[2] The reforestation of once open land has also negatively impacted the eastern Bewick's wrens.[2]
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.[14]
In Washington, development has actually benefited the Bewick's wren, leading to an increase in its population. However, this has coincided with the decline of the Pacific wren thanks to increased competition between the two species.[20]
Illustration from Audubon's The Birds of America The Bewick's wren (Thryomanes bewickii) is a wren native to North America. It is the only species placed in the genus Thryomanes. At about 14 cm (5.5 in) long, it is grey-brown above, white below, with a long white eyebrow. While similar in appearance to the Carolina wren, it has a long tail that is tipped in white. The song is loud and melodious, much like the song of other wrens. It lives in thickets, brush piles and hedgerows, open woodlands and scrubby areas, often near streams. It eats insects and spiders, which it gleans from vegetation or finds on the ground.
Its historic range was from southern British Columbia, Nebraska, southern Ontario, and southwestern Pennsylvania, Maryland, south to Mexico, Arkansas and the northern Gulf States. However, it is now extremely rare east of the Mississippi River.
