Mourning warbler

The mourning warbler (Geothlypis philadelphia) is a small songbird of the New World warbler family. Mourning warblers are native to eastern and central North America as well as some countries in Central America. They are neotropical migrants and tend to be found in dense second growth forests. They are under the Wood-warbler category, which consists of arboreal and terrestrial colorful passerines. Wood warblers are in the order Passeriformes, which are perching birds including more than half of all bird species, and the family Parulidae which also includes the Common Yellowthroat, Black and White Warbler, Nashville Warbler, ovenbird, and American Redstart. They are very similar to the MacGillivray's Warbler in appearance, especially in females and immature birds, but their breeding range does not overlap into the west.

The "mourning" in this bird's name refers to the male's hood, thought to resemble a mourning veil.

Identification
Mourning warblers are small songbird with yellow underparts, olive-green upperparts, a thin pointed bill and pink legs. Adult males have a gray hood, black lores and a black patch on the throat and breast. In the fall, this pattern becomes less bright and harder to distinguish from similar species; however they never have a broken eye ring. Females and immatures are gray-brown on the head with an incomplete eye-ring. They have a yellow-gray throat with a brown or olive tint to their breast. Both sexes can range from 10–15 cm (3.9-5.9 in) in length and 11-13 g (0.4-0.5 oz) in weight. Their wingspan is 18 cm (7.1 in). Other than the MacGillivray’s Warbler, similar species include the Connecticut warblers which have a complete eye ring, not to be confused with a broken eye ring seen on immature Mourning warblers. Immature Connecticut warblers also have a whiter chest compared to the yellow chest on immature Mourning warblers. Nashville warblers are also commonly confused; however they have a yellow throat unlike the black or grey throats of Mourning warblers, females have a grey back, and they are smaller and less active than Mourning warblers.

Distribution and habitat
Mourning warblers have breeding ground in southern Canada, and are commonly seen during migration in the central and eastern United States, Belieze, Bonaire, Puerto Rico, Guatemala, Panama, and other Central American Islands. These birds migrate to Central America and northern South America. Mourning warblers are low or ground nesters, and prefer disturbed forests with a thick under-story and covered canopy. In the winter they prefer wet lowland habitat with dense vegetation.

Diet
Mourning warblers forage low in vegetation, sometimes catching insects in flight. These birds mainly eat insects, also some plant material including fruiting bodies from the Cecropia tree in winter. Their diet is not well documented but also includes insect larvae and spiders that they pick from the branches of shrubs. They are also known to remove the legs and wings of the insects before consuming.

Breeding
Mourning warblers breed in southern Canada. Their breeding habitat is thickets and semi-open areas with dense shrubs across Canada east of the Rockies and the northeastern United States. The nest is an open cup placed on the ground in a well-concealed location under thick shrubs or other vegetation. Their nest is usually made out of grass, leaves and bark and lined with roots or other thin material.

Mourning warblers typically lay 2-5 eggs, which are white or speckled brown and black in appearance. Incubation is 12 days long and both adult males and females utilize a distraction technique of pretending to have broken wings to distract predators from their nest. Mourning warblers have young with gray tufts on their head and red mouths. Adult females are also known consume their eggs after their young hatch. The number of days for young to fledge is 7–9.

Vocalization
The song of this bird is a bright repetitive warble. The warble consists of rolling phrases that sound that typically lower in volume at the end and can sound like "chirry, chirry, chirry, chorry, chorry." The call is a sharp chip. There are usually two different pitched calls, with one higher than the harsh chip.

Conservation
According to the North American Breeding Bird Survey, Mourning Warbler populations have declined by about 43% in the last 50 years. However, they are still categorized as a species of least concern with 17 million estimated as a global breeding population by Partners in Flight. As they have a preference for disturbed forests, they may be benefitting from human development that may be negatively effecting the habitats of other bird species.

Books

 * Pitocchelli, Jay. 1993. Mourning Warbler (Oporornis philadelphia). In The Birds of North America, No. 72 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union.

Thesis

 * Kingsley AL. M.Sc. (1998). Response of birds and vegetation to the first cut of the uniform shelterwood silvicultural system in the white pine forests of Algonquin Provincial Park, Ontario. Trent University (Canada), Canada.
 * Pitocchelli J. Ph.D. (1988). Character variation in the Oporornis philadelphia-tolmiei complex. City University of New York, United States, New York.
 * Woodcock JM. M.Sc. (1997). Effects of manual, mechanical, and aerial herbicide conifer release on songbird numbers in regenerating spruce plantations in northwestern Ontario. Lakehead University (Canada), Canada.

Articles
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 * Benson A-M, Pogson TH & Doyle TJ. (2000). Updated geographic distribution of eight passerine species in central Alaska. Western Birds. vol 31, no 2. p. 100-105.
 * Bledsoe AH. (1988). A Hybrid Oporornis-Philadelphia X Geothlypis-Trichas with Comments on the Taxonomic Interpretation and Evolutionary Significance of Intergeneric Hybridization. Wilson Bulletin. vol 100, no 1. p. 1-8.
 * Burris JM & Haney AW. (2005). Bird communities after blowdown in a late-successional Great Lakes spruce-fir forest. Wilson Bulletin. vol 117, no 4. p. 341-352.
 * Canterbury GE & Blockstein DE. (1997). Local changes in a breeding bird community following forest disturbance. Journal of Field Ornithology. vol 68, no 4. p. 537-546.
 * Collins SL, James FC & Risser PG. (1982). Habitat Relationships of Wood warblers Parulidae in Northern Central Minnesota USA. Oikos. vol 39, no 1. p. 50-58.
 * Hall GA. (1979). Hybridization between Mourning Warbler Oporornis-Philadelphia and Macgillivarays Warbler Oporornis-Tolmiei. Bird Banding. vol 50, no 2. p. 101-107.
 * Hanowski J, Danz N, Lind J & Niemi G. (2003). Breeding bird response to riparian forest harvest and harvest equipment. Forest Ecology & Management. vol 174, no 1-3. p. 315-328.
 * Harrison RB, Fiona KAS & Robin N. (2005). Stand-level response of breeding forest songbirds to multiple levels of partial-cut harvest in four boreal forest types. Canadian Journal of Forest Research. vol 35, no 7. p. 1553.
 * Hobson KA & Schieck J. (1999). Changes in bird communities in boreal mixedwood forest: Harvest and wildfire effects over 30 years. Ecological Applications. vol 9, no 3. p. 849-863.
 * Holmes SB & Pitt DG. (2007). Response of bird communities to selection harvesting in a northern tolerant hardwood forest. Forest Ecology & Management. vol 238, no 1-3. p. 280-292.
 * Jobes AP, Nol E & Voigt DR. (2004). Effects of selection cutting on bird communities in contiguous eastern hardwood forests. Journal of Wildlife Management. vol 68, no 1. p. 51-60.
 * Lemon RE, Struger J & Lechowicz MJ. (1983). Song Features as Species Discriminants in American warblers Parulidae. Condor. vol 85, no 3. p. 308-322.
 * Lent RA & Capen DE. (1995). Effects of small-scale habitat disturbance on the ecology of breeding birds in a Vermont (USA) hardwood forest. Ecography. vol 18, no 2. p. 97-108.
 * Niemi GJ & Hanowski JM. (1984). Relationships of Breeding Birds to Habitat Characteristics in Logged Areas. Journal of Wildlife Management. vol 48, no 2. p. 438-443.
 * Pitocchelli J. (1990). Plumage Morphometric and Song Variation in Mourning Oporornis-Philadelphia and Macgillivray's Oporornis-Tolmiei warblers. Auk. vol 107, no 1. p. 161-171.
 * Pitocchelli J. (1992). Plumage and Size Variation in the Mourning Warbler. Condor. vol 94, no 1. p. 198-209.
 * Schulte LS & Niemi GJ. (1998). Bird communities of early-successional burned and logged forest. Journal of Wildlife Management. vol 62, no 4. p. 1418-1429.
 * Scott DM. (1988). Breeding Records of the Mourning Warbler at London Middlesex County Canada. Ontario Birds. vol 6, no 1. p. 32-33.
 * Sodhi NS & Paszkowski CA. (1995). Habitat use and foraging behavior of four parulid warblers in a second-growth forest. Journal of Field Ornithology. vol 66, no 2. p. 277-288.

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