Chestnut-sided warbler | |
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Adult in summer plumage | |
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Nonbreeding plumage (female or immature male) | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
Family: | Parulidae |
Genus: | Setophaga |
Species: | S. pensylvanica |
Binomial name | |
Setophaga pensylvanica (Linnaeus, 1766) | |
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Breeding range Wintering range | |
Synonyms | |
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The chestnut-sided warbler (Setophaga pensylvanica) is a New World warbler. They breed in eastern North America and in southern Canada westwards to the Canadian Prairies. They also breed in the Great Lakes region and in the eastern United States.
The genus name Setophaga is from Ancient Greek ses, "moth", and phagos, "eating", and the specific pennsylvanicus means "Pennsylvania". [2] Setophaga icterocephala is a junior synonym of S. pennsylvanicus, and is no longer used. [3]
The chestnut-sided warbler used to be in the genus Dendroica; however, it was merged with the genus Setophaga in 2011. [4] The change resulted with Setophaga having the most species in the family of New World warblers. [3]
No subspecies have been described.
This species is a moderately-sized New World warbler. Despite having very different plumage, it is thought to be closely related to the widespread yellow warbler. In total, this species measures from 10 to 14 cm (3.9 to 5.5 in) in length and spans 16 to 21 cm (6.3 to 8.3 in) across the wings. Body weight ranges from 8 to 13.1 g (0.28 to 0.46 oz). Among standard measurements, the wing chord is 5.7 to 6.8 cm (2.2 to 2.7 in), the tail is 4.2 to 5.8 cm (1.7 to 2.3 in), the bill is 0.9 to 1 cm (0.35 to 0.39 in) and the tarsus is 1.7 to 1.9 cm (0.67 to 0.75 in). [5]
In the summer, male chestnut-sided warblers are unmistakable in appearance. They display dark-streaked gray backs, white faces, black eyestripes and yellow crowns. Their underparts are white, with chestnut flanks, and they also have two white wing bars. The adult females resemble washed-out versions of the summer male, and in particular, the females lack the strong head pattern, and also have little to no chestnut coloring on their flanks.
Non-breeding birds of both sexes have bright yellow-green crowns, white eye-rings on a grey face, and unstreaked underparts. They also have unstreaked pale grey breasts. Their wing bars are always present in their plumages.
The chestnut-sided warbler has benefited from the clearing of mature forests in their breeding ranges. They make use of the abundant second growth habitats, forests after clearcuttings and/or fires. [6] Their numbers increase as soon as a year after clear-cuts, peaking seven to eight years after the disturbance. [7]
In the tropics where they winter, the species occurs mostly in mature tropical rainforests where they tend to stick to the mid- to upper- canopy. They are known to use coffee plantations and riparian zones in Costa Rica. [7]
The chestnut-sided warbler breeds in Eastern North America, from Saskatchewan to the Maritimes. [8] Although an observation of a male in breeding plumage was recorded as far West as British Columbia. [9] They are usually found south of the 50°N, with the north-west Georgia as the most southern extent of their breeding range. [8]
They overwinter in Central America to northern Colombia, [10] with a confirmed sighting [11] from as far south as Ecuador. While they mainly spend their non-breeding period in Central America, with the highest numbers in Costa Rica, the chestnut-sided warbler does winter in southern parts of Mexico and some north-western parts of South America. [7]
These birds are Neotropical migrants, and are very rare vagrants to western Europe. Their breeding season starts in May in North America, and they start their fall migration as early as late August to as late as late September. the chestnut-sided warbler migrates east of the Rocky Mountains, through Bahama, the Greater Antilles and eastern Mexico. The chestnut-sided warbler departs their wintering grounds sometime in April. They tend to stick to migrating through parts of Mexico and east of the Rocky Mountains with few passing by the Caribbean during the spring migration. Males arrive on the breeding grounds a few days to a week before the females. [7]
The songs are high whistled lines often described as pleased, pleased, pleased to MEECHA. This accented song is used primarily to attract a female and decrease in frequency once nesting is well under way. Males also sing unaccented songs (without the MEECHA at the end) and these are used mostly in territory defense and aggressive encounters with other males. [12] Some versions of the unaccented songs are not as commonly used in general, but rather reserved for aggressive contexts. While it does guarantee that the bird will attack, it does represent an escalation to an intruder. [13] Some males sing only unaccented songs, and they are less successful at securing mates than males that sing both songs. Their calls are harsh chips. Despite the fact that songs for courtship do not vary across small distances, songs for aggression are highly localized, a possible explanation being that female Chestnut-Sided Warblers disperse over long distances. [12]
Chestnut-sided warblers are primarily insectivorous. [14] They feed primarily on lepidopteran and dipteran larvae, and will sometimes eat spiders, seeds, and fruits. [7] They forage actively in shrubs and small trees, and sometimes will attempt to catch insects in mid-air. Most foraging consists of gleaning insects from foliage. They will include berries in their winter diets, such as those of Cymbopetalum mayanum ; such trees can be used to attract wintering birds into gardens and parks. [14] Chestnut-sided warblers forage alone. [7]
It is thought that chestnut-sided warblers started reproducing in their first year. Since the males arrive first on the breeding grounds, they will establish their territory. However, it appears that females decide where to build their nest. [7] Their nests are placed in a low bush, which is usually located in young deciduous woodland or scrub. Females build the nest into a small cup woven of bark strips, weed stems, grasses, and plant down. The nest is usually placed in a small crotch of a shrub or vertical tangle of vines no more than 2 m (6.6 ft) above the ground. [8] This species is frequently parasitized by brown-headed cowbirds (Molothrus ater). These birds lay 3–5 eggs that are creamy white or greenish with brown speckles in color. Usually, couples will only have one clutch; however, they might have a second clutch if the first one fails. [7]
Researchers have noted agonistic behavior between male chestnut-sided warblers and golden-winged warblers (Vermivora chrysoptera) during the breeding season in the southern Appalachians. Interestingly, aggressive behavior was not a guarantee if males of both species came across each other. [15]
On May 25, 2014, the Long Point Bird Observatory (Ontario, Canada) recorded a new hybrid: a chestnut-sided warbler hybrid with a magnolia warbler (Setophaga magnolia). The individual was caught in a mist-net at the Long Point's research station Old Cut. Genetic and morphological evidence points to the mother being a chestnut-sided warbler and the father being a magnolia warbler. [16]
A Brewster's warbler with two small brown spots on its throat was documented in Pennsylvania in 2018. Brewster's warblers are a hybrid of golden-winged warbler (Vermivora chrysoptera) and blue-winged warbler (Vermivora cyanoptera). The chestnut spots and its class pointed to the individual having a chestnut-sided warbler parent, making it a three-species hybrid. It was later confirmed through genetic tests that the father was a chestnut-sided warbler, and the mother was a Brewster's warbler. [17] The extremely rare hybrid was named Burket's warbler after the person who first made the observation of the individual. [18]
Billy Weber uploaded his observation of a chestnut-sided warbler and black-throated blue warbler (Setophaga caerulescens) hybrid to ebird in 2019. The hybrid, located in Pennsylvania, visually looked like a male black-throated blue warbler with brown sides. [19]
The chestnut-sided warbler might have hybridized on two other accounts. the Handbook on Avian Hybrids of the World highlights a black-and-white warbler (Mniotilta varia) hybrid and a blackburnian warbler (Setophaga fusca) hybrid who might have had a chestnut-sided warbler parent. However, other species were also suggested to have contributed to creating the hybrids, and no genetic tests were performed to confirm one way or another. [20]
This bird's numbers have increased as second growth forest became more common in the east in the late 19th century; their numbers have declined slightly since then. The Breeding Bird Survey BBS in New England has shown an overall decrease in population from 1966 to 2015, but an increase in Pennsylvania. Local population trends are most likely tied to habitat changes. [7]
The yellow-rumped warbler is a regular North American bird species that can be commonly observed all across the continent. Its extensive range connects both the Pacific and Atlantic coasts of the U.S. as well as Canada and Central America, with the population concentrated in the continent's northern reaches during the breeding season and migrating southwards to southern North and Central America in the winter. It generally prefers coniferous forests or mixed coniferous-deciduous forests as its breeding habitat, while during the winter it can be found inhabiting more open areas such as shrublands that offer food resources. The yellow-rumped warbler is primarily insectivorous, though the species does eat fruits such as juniper berries as well, especially in winter.
Audubon's warbler is a small bird of the family Parulidae. At one time considered a distinct species, discovery of a hybrid zone between it and the myrtle warbler in 1973 has led to it being classified as a subspecies of the yellow-rumped warbler.
The Cape May warbler is a species of New World warbler. It breeds in northern North America. Its breeding range spans all but the westernmost parts of southern Canada, the Great Lakes region, and New England. It is migratory, wintering in the West Indies. This species is a very rare vagrant to western Europe, with two records in Britain as of October 2013. The English name refers to Cape May, New Jersey, where George Ord collected the specimen later described by Alexander Wilson. This species was not recorded again in Cape May for another 100 years, although it is now known as an uncommon migrant there.
The Blackburnian warbler is a small New World warbler. They breed in eastern North America, from southern Canada, westwards to the southern Canadian Prairies, the Great Lakes region and New England, to North Carolina.
The blackpoll warbler is a New World warbler. Breeding males are mostly black and white. They have a prominent black cap, white cheeks, and white wing bars. The blackpoll breeds in forests of northern North America, from Alaska throughout most of Canada, to the Adirondack Mountains of New York as well as New England in the Northeastern United States. They are a common migrant throughout much of North America. In fall, they fly south to the Greater Antilles and the northeastern coasts of South America in a non-stop long-distance migration over open water, averaging 2,500 km (1,600 mi), one of the longest-distance non-stop overwater flights ever recorded for a migratory songbird. Rare vagrants to western Europe, they are one of the more frequent transatlantic passerine wanderers.
The magnolia warbler is a member of the wood warbler family Parulidae.
The yellow warbler is a New World warbler species. Yellow warblers are the most widespread species in the diverse genus Setophaga, breeding in almost the whole of North America, the Caribbean, as well as northern South America.
The bay-breasted warbler is a small species of songbird in the New World warbler family, Parulidae. It is one of thirty-four species in the diverse genus Setophaga. Like all songbirds, or passerines, the species is classified in the order Passeriformes.
The American redstart is a New World warbler. It is unrelated to the Old World (common) redstart.
The golden-winged warbler is a New World warbler. It breeds in southeastern and south-central Canada and in the Appalachian Mountains in northeastern to north-central United States. The majority (~70%) of the global population breeds in Wisconsin, Minnesota, and Manitoba. Golden-winged warbler populations are slowly expanding northwards, but are generally declining across its range, most likely as a result of habitat loss and competition/interbreeding with the very closely related blue-winged warbler, Vermivora cyanoptera. Populations are now restricted to two regions: the Great Lakes and the Appalachian Mountains. The Appalachian population has declined 98% since the 1960s and is significantly imperiled. The U.S. Fish and Wildlife Service has been petitioned to list the species under the Endangered Species Act of 1973 and is currently reviewing all information after issuing a positive finding. Upon review, the U.S. Fish and Wildlife Service found that the petition to list the species as endangered or threatened presents "substantial scientific or commercial information indicating that listing the golden-winged warbler may be warranted."
The blue-winged warbler is a fairly common New World warbler, 11.5 cm (4.5 in) long and weighing 8.5 g (0.30 oz). It breeds in eastern North America in southern Ontario and the eastern United States. Its range is extending northwards, where it is replacing the very closely related golden-winged warbler.
The black-throated green warbler is a small songbird of the New World warbler family.
The black-throated blue warbler is a small passerine bird of the New World warbler family. Its breeding ranges are located in the interior of deciduous and mixed coniferous forests in eastern North America. Over the cooler months, it migrates to islands in the Caribbean and Central America. It is very rarely found in western Europe, where it is considered to be a non-indigenous species. The black-throated blue warbler is sexually dimorphic; the adult male has a black face and cheeks, deep blue upperparts and white underparts, while the adult female is olive-brown above and light yellow below.
The cerulean warbler is a small songbird in the family Parulidae. It is a long-distance migrant, breeding in eastern North American hardwood forests. In the non-breeding season, it winters on the eastern slope of the Andes in South America, preferring subtropical forests.
The prairie warbler is a small songbird of the New World warbler family.
The palm warbler is a small songbird of the New World warbler family.
The yellow-throated warbler is a small migratory songbird species in the New World warbler family (Parulidae) found in temperate North America.
The black-throated gray warbler or black-throated grey warbler is a passerine bird of the New World warbler family Parulidae. It is 13 cm (5.1 in) long and has gray and white plumage with black markings. The male has the bold black throat of its name, and black stripes on its head, as well as black streaks on its flanks; the female is a paler version of the male, with a white throat and less distinct black markings on the flanks and wings. It breeds in western North America from British Columbia to New Mexico, and winters in Mexico and the southwestern United States. The habitats it prefers are coniferous and mixed forests and scrubland, especially those with pinyon pines, junipers, sagebrush, and oaks. Its nest is an open cup of plant fibers lined with feathers, built a few metres from the ground in the branches of a tree or shrub. Three to five eggs are laid, and young are fed by both parents. Common in its breeding range, it does not seem to be seriously threatened by human activities, unlike many migratory warblers.