Rusty blackbird

The rusty blackbird (Euphagus carolinus) is a medium-sized New World blackbird, closely related to grackles ("rusty grackle" is an older name for the species). It is a bird that prefers wet forested areas, breeding in the boreal forest and muskeg across northern Canada, and migrating southeast to the United States during winter.

Formerly abundant, the rusty blackbird has undergone one of the most rapid declines of any abundant bird species in North America in recent years, for reasons that are not well understood.

Description
Adults have a pointed bill and a pale yellow eye. They have black plumage with faint green and purple gloss; the female is greyer. "Rusty" refers to the brownish winter plumage. They resemble the western member of the same genus, the Brewer's blackbird; however, Brewer's has a longer bill and the male's head is iridescent green.



Habitat
Their breeding habitat is wet temperate coniferous forests and muskeg across Canada, New England, the Upper Peninsula of Michigan, the Adirondack Mountains in New York and Alaska. Birds usually nest at the edge of ponds and wetlands with the cup nest located in a tree or dense shrub, often over the water. Emerging dragonflies and their larvae are important food items during the summer.

These birds migrate to the eastern and southeastern United States, into parts of the Grain Belt, sometimes straying into Mexico. Additional vagrants have been reported inn Greenland and Russian Siberia.

Behavior
They forage on wet ground or in shallow water, mainly eating insects, small fish and some seeds. Their most common mode of foraging is to vigorously flip leaves and rip at submerged aquatic vegetation. The mast of small-acorn producing oaks, such as willow oak, is also important. In some areas, the nuts of planted pecans are heavily used. They very rarely will attack small passerine birds, and have been known to kill species as large as the Wilson's snipe. They feed in flocks during migration and on the wintering grounds, sometimes joining other blackbirds, both often occurring in single species flocks. They more often roost with other blackbirds; some small roosts are in brushy vegetation in old fields and others are in massive mixed flocks—sometimes in the urban areas.

The species nests relatively early for a boreal forest bird. They linger in the boreal zone to complete their molt. Their autumn migration is slow, with birds often remaining in the northern states well into December; spring migration is much more rapid. The largest wintering concentrations are found in the lower Mississippi Valley, with smaller concentrations in the Piedmont and south Atlantic coastal plain.

Fairly quiet in fall migration and most of the winter, both males and females will sing (particularly on warm days) in the late winter and spring. The song consists of gurgling and high-pitched squeaks.

Population
Rusty blackbirds have declined significantly in recent decades. The reasons are unclear, but habitat loss is likely a major contributor to the decline. The habitat loss is likely due to multiple factors, including development for oil, gas, and mining industries, hydroelectric projects, and the clearing of forests for forestry. Mercury contamination may be a problem for populations in northeastern North America. Rarer than previously believed, it was uplisted from a species of Least Concern to Vulnerable status on the 2007 IUCN Red List. Deliberate poisoning of mixed-species blackbird flocks, targeting brown-headed cowbird, common grackle and red-winged blackbird, in the southeastern U.S. may also be playing a role; there is currently no estimate of the number of rusty blackbirds killed by these poisonings. In the eastern part of its range, acid rain may be decreasing the availability of calcium-rich invertebrates that the rusty blackbird depends on for food.

Additionally, citizen science projects such as the North American Breeding Bird Survey and Christmas Bird Count have determined that rusty blackbirds have dropped 85%–98% in the past 40 years. This is very worrisome for many people, as scientists are desperately trying to figure out what exactly went wrong. Sighting submission services such as eBird are encouraging birders to keep track of rusty blackbirds. The International Rusty Blackbird Working Group has been actively coordinating and conducting research on this species since 2005.

Book

 * Avery, M. L. 1995. Rusty Blackbird (Euphagus carolinus). In The Birds of North America, No. 200 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The American Ornithologists’ Union, Washington, D.C.

Articles
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 * Besser JF. (1978). Birds and Sunflower. In Carter, Jack F (Ed) Agronomy, No 19 Sunflower Science and Technology Xx+505p Illus American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, Inc., Publishers: Madison, Wis, USA ISBN 0-89118-054-0 263-278, 1978.
 * Campbell RW. (1974). Rusty Blackbirds Prey on Sparrows. Wilson Bulletin. vol 86, no 3. p. 291-293.
 * Cicchino AC & Castro DC. (1996). Preliminary revision of the species of the genus Brueelia Keler, 1936 (Phthiraptera, Philopteridae) parasitizing Icterinae (Aves, Passeriformes, Fringillidae). Graellsia. vol 52, no 0. p. 3-30.
 * Crase FT & Dehaven RW. (1976). Selected Bibliography on the Food Habits of North American Blackbirds. U S Fish & Wildlife Service Special Scientific Report Wildlife. vol 192, p. 1-20.
 * Dickson JG & Noble RE. (1978). Vertical Distribution of Birds in a Louisiana USA Bottomland Hardwood Forest. Wilson Bulletin. vol 90, no 1. p. 19-30.
 * Dolbeer RA, Woronecki PP, Stickley ARJ & White SB. (1978). Agricultural Impact of a Winter Population of Blackbirds and Starlings. Wilson Bulletin. vol 90, no 1. p. 31-44.
 * Dyer MI & Kakalec NJ. (1976). Studies on Diet Overlap among Icterids Crows and Starlings. Proceedings Bird Control Seminar. vol 7, p. 136-146.
 * Fritzell EK & Thorne DH. (1984). Birds Predominate in the Winter Diet of a Barn Owl Tyto-Alba. Wilson Bulletin. vol 96, no 2.
 * Garner KM. (1978). Management of Blackbird and Starling Winter Roost Problems in Kentucky and Tennessee USA. Proceedings of the Vertebrate Pest Conference. vol 8, p. 54-59.
 * Grass A. (1969). Rusty Blackbird at Pitt Meadows British-Columbia. Murrelet. vol 50, no 2.
 * Greenberg R & Droege S. (1999). On the decline of the Rusty Blackbird and the use of ornithological literature to document long-term population trends. Conservation Biology. vol 13, no 3. p. 553-559.
 * Hudon J & Muir AD. (1996). Characterization of the reflective materials and organelles in the bright irides of North American blackbirds (Icterinae). Pigment Cell Research. vol 9, no 2. p. 96-104.
 * Hunter JE. (1994). Further observations of head-down displays by brown-headed cowbirds. Western Birds. vol 25, no 1. p. 63-65.
 * Larue P, Belanger L & Huot J. (1995). Riparian edge effects on boreal balsam fir bird communities. Canadian Journal of Forest Research. vol 25, no 4. p. 555-566.
 * Long RC & Russ A. (1968). Rusty Blackbird Kills House Sparrow. Ontario Field Biologist. vol 22, no 28.
 * McCaskie G. (1971). Rusty Blackbirds in California and Western North America. California Birds. vol 2, no 2. p. 55-68.
 * Meanley B & Royall WCJ. (1976). Nationwide Estimates of Blackbirds and Starlings. Proceedings Bird Control Seminar. vol 7, p. 39-40.
 * Norment CJ, Hall A & Hendricks P. (1999). Important bird and mammal records in the Thelon River valley, Northwest Territories: Range expansions and possible causes. Canadian Field Naturalist. vol 113, no 3. p. 375-385.
 * Peck MK, Coady G, Binsfeld G, Konze KR, Hodgson PC & Furino S. (2004). Ontario Breeding Bird Atlas expeditions yield additional information on solitary sandpiper nests. Ontario Birds. vol 22, no 3. p. 120-124.
 * Robertson RJ, Weatherhead PJ, Phelan FJS, Holroyd GL & Lester N. (1976). Species Composition Food Habits and the Economic and Ecologic Impact of Winter Blackbird Flocks. Proceedings Bird Control Seminar. vol 7, p. 155-162.
 * Rybczynski R & Riker DK. (1981). A Temperate Species-Rich Assemblage of Migrant Frugivorous Birds. Auk. vol 98, no 1. p. 176-179.
 * Smith TG. (1973). The Birds of the Holman Region Western Victoria Island. Canadian Field Naturalist. vol 87, no 1. p. 35-42.
 * Tallman D. (1990). Banding Recoveries of South Dakota USA Birds Part 2 Larks Corvids Starling and Blackbirds. South Dakota Bird Notes. vol 42, no 2. p. 29-36.
 * Wass ML. (1975). Hitchcock Revisited Burgeoning Blackbirds. ASB Bulletin. vol 22, no 2.