American Mourning Dove Habitats: Gray Body, Platform Nest, White Egg

Summary: North American mourning dove habitats seasonal outside the Caribbean, Mexico and the United States year-round get gray bodies, platform nests, white eggs.

mourning dove (Zenaida macroura) in a backyard in Toronto, Golden Horseshoe region, Southern Ontario, east central Canada, 2005: Mdf, CC BY SA 3.0 Unported, via Wikimedia Commons

North American mourning dove habitats abet cultivators with Columbidae dove and pigeon family member appetites for weed seeds and naturalists with distribution ranges year-round from southwestern Canada through Mexico and Caribbean America.

Mourning doves bear their common name for their call and the scientific name Zenaida macroura as a princess's namesake genus and a species' signature long tail. The genus commemorates Zénaïde Laetitia Julie (July 8, 1801-Aug. 8, 1854), wife of ornithologist and prince Charles Lucien Jules Laurent Bonaparte (May 24, 1803-July 29, 1857). Its species divides into the gray-brown, larger carolinensis (Carolina) subspecies east of the Mississippi River and the paler, smaller marginella (marginal) subspecies to the Mississippi's west.

Mourning doves, described in 1758 by Swedish zoologist Carl Linnaeus (May 23, 1707-Jan. 10, 1787), expect 19-year-lifespans in deserts, fields, grasslands, parklands, scrublands, semi-deserts and woodlands.

February through September facilitate brooding two two- to four-egg clutches or more amid vines, at 10- to 50-foot (3.05- to 15.24-meter) heights or on the ground.
Parents-to-be gather sticks and twigs over two to four days into occasionally grass-, rootlet-, weed-lined platform nests sometimes on old grackle, gray catbird or robin nests. Nests house bright white, oval to elliptical, smooth, somewhat glossy, unmarked 0.87- to 1.18-inch- (22- to 30-millimeter-) long, 0.43- to 0.87-inch- (11- to 22-millimeter-) wide eggs. Thirteen- to 15-day incubations of eggs laid alternately and successively in the evening and the morning involve fathers-to-be during the day and mothers-to-be during the night.

Hunting, poisoning from fallen lead shot and from pesticide-riddled prey and predation by black rat snakes, falcons, hawks and raccoons jeopardize North American mourning dove habitats.

Parents-to-be keep helpless hatchlings and nestlings with short, sparse, stringy white down over yellow skin fed through crop-milk secretions from adult female and male neck pouches.

Nestlings learn to fledge as 11- to 13-day-olds even though they leave parent-tended nests in soils and woody plants or on ledges as 25- to 27-day-olds. Mourning doves, physically and sexually mature 85 days after hatching, manage diets of ants, beetles, crickets, grasshoppers and snails; berries, grains, nuts and seeds; and grit. Adults need cereal grains such as barley, corn, millet, oats, rye and wheat; peanuts; and seeds from herbs, sunflowers, trees such as pines and wild grasses.

North American mourning dove habitats up to 8,202.1 feet (2,500 meters) above sea level offer winter-coldest temperatures at minus 45 degrees Fahrenheit (minus 42.77 degrees Celsius).

Acacia, ash, aspen, basswood, beech, birch, cherry, cottonwood, elm, hawthorn, hickory, locust, mahogany, maple, mesquite, oak, persimmon, poplar, sassafras, sugarberry, sycamore, tamarack and willow provide cover. Blackbrush, bluegrass, bluestem, buffalograss, cedar, cordgrass, cypress, fescue, fir, grama-grass, hemlock, needlegrass, oatgrass, palmetto, paloverde, pine, sagebrush, saltbush, sea-oats, spruce, tarbush and wheatgrass qualify as camouflage.

Black-dotted sides of faces, dark, thin bills, dark-spotted gray wings, gray-tan bodies and long, pointed tails reveal pink-legged, pink-toed, rosy-breasted, small-headed adults with neck-mottled, underpart-mottled juveniles. Direct, quick-beat, twisting flight on 14.57- to 17.72-inch (37- to 45-centimeter) wingspans suggest 2.99- to 6.17-ounce (85- to 175-gram), 9.06- to 13.39-inch (23- to 34-centimeter) adults.

North American mourning dove habitats transmit coo, coo-oo and coo-oo-oo calls of perching males, ohr-ohr sounds of nesting females, mellow owl-like hoO-Oo-oo hoo-hoo-hoo vocalizations and whistles.

mourning dove (Zenaida macroura) egg in hanging planter; Friday, Aug. 1, 2003, 17:59: Mr walsh at English Wikipedia, Public Domain, via Wikimedia Commons

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

mourning dove (Zenaida macroura) in a backyard in Toronto, Golden Horseshoe region, Southern Ontario, east central Canada, 2005: Mdf, CC BY SA 3.0 Unported, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Zenaida_macroura1.jpg

mourning dove (Zenaida macroura) egg in hanging planter; Friday, Aug. 1, 2003, 17:59: Mr walsh at English Wikipedia, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Mourning_Dove_Egg.JPG

For further information:

Baicich, Paul J.; and Harrison, Colin J.O. Nests, Eggs, and Nestlings of North American Birds. Second edition. Princeton NJ: Princeton University Press, Princeton Field Guides, 2005.

Grzimek's Animal Life Encyclopedia, 2nd edition. Volumes 8-11, Birds I-IV, edited by Michael Hutchins, Jerome A. Jackson, Walter J. Bock and Donna Olendorf. Farmington Hills MI: Gale Group, 2002.

Linnaeus, Carl. 1758. "16. Columba macroura." Systema Naturae per Regna Tria Naturae, Secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis, Tomus I, Editio Decima, Reformata: 164. Holmiae: Laurentii Salvii.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/727071

Linnaeus, Carl. 1766. "37. Columba macroura carolinensis." Systema Naturae, tomus I: 286. Editio Duodecima, Reformata. Holmiae [Stockholm, Sweden]: Laurentii Salvii [Laurentius Salvius].
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/42946482

Peterson, Alan P., M.D. "Zenaida macroura (Linnaeus) 1758." Zoonomen: Zoological Nomenclature Resource > Birds of the World -- Current Valid Scientific Avian Names > Columbiformes > Columbidae > Zenaida.
Available @ http://www.zoonomen.net/avtax/colu.html

Townsend, Chas. H. (Charles Haskins). 1891. "No. XIV. Birds From the Coasts of Western North America and Adjacent Islands, Collected in 1888 and '89, With Descriptions of New Species: I. Clarion Island: Zenaidura clarionensis  sp. nov." Proceedings of the United States National Museum, vol. XIII (1890), no. 799: 133. Washington DC: Government Printing House.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/15670849

Wetmore, Alexander. 12 September 1956. "Additional Forms of Birds From Panamá and Colombia: Zenaidura macroura turturilla subsp. nov." Proceedings of the Biological Society of Washington, vol. 69: 123-125. Baltimore MD: Monumental Printing Co.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/34549817
Available via HathiTrust @ https://hdl.handle.net/2027/uc1.31822006518377?urlappend=%3Bseq=126

Woodhouse, S.W. (Samuel Washington), M.D. June 1852. "Description of a New Species of Ectopistes: Ectopiste marginella, nobis." Proceedings of the Academy of Natural Sciences of Philadelphia, vol. VI (1852, 1853): 104-105. Philadelphia PA: Merrihew & Thompson, 1854.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/1779640

North American Red-Tailed Hawk Habitats: Brown Body, Nest Pile, White Egg

Summary: White eggs in nest piles give North American red-tail hawk habitats brown bodies seasonally in Canada and Mexico, year-round in the United States.

North American red-tailed hawk (Buteo jamaicensis) at John Heinz National Wildlife Refuge, Philadelphia, southeastern Pennsylvania; January 2011: Mark Bohn/U.S. Fish and Wildlife Service, Public Domain, via USFWS National Digital Library

North American red-tailed hawk habitats allay cultivator anxieties with Accipitridae raptor family member appetites for field animals and hunters and naturalists with distribution ranges from Canada southward through Mexico and the Caribbean.

Red-shouldered hawks bear their common name and the scientific name Buteo jamaicensis (Jamaican buzzard) for colorfully mature tails and the location of the first European-described specimens. Predatory humans and secondary poisoning from consuming lead- or warfarin-containing animals challenge red-tailed hawks, described in 1788 by Johann Friedrich Gmelin (Aug. 8, 1748-Nov. 1, 1804). Bio-geography and physique divide them into continental alascensis, borealis, calurus, costaricensis, fuertesi, hadropus, harlani, kemsiesi, kriderii and umbrinus and insular fumosus, nominate, socorroensis and solitudinus subspecies.

Twenty-one-year lifespans expect nest-friendly, perch-worthy buildings, cacti, cliffs, outcrops, poles, snags or trees in bottomlands, clearings, estuaries, fields, grasslands, marshes, meadows, parklands, prairies, rangelands or savannas.

February through September facilitate brooding one two- to five-egg clutch in nest piles in buildings, shrubs, snags, towers or trees or on cacti, cliffs and outcrops.

Monogamous parents-to-be gather twigs into bark-, stem-lined, 4- to 6-inch- (10.16- to 15.24-centimeter-) deep, permanent nest piles 35 to 90 feet (10.67 to 27.43 meters) up. Nests with inner 14- to 15-inch (35.56- to 38.1-centimeter), outer 28- to 38-inch (71.12- to 96.52-centimeter) diameters house buff-washed, elliptical to subelliptical, non-glossy, smooth white eggs. Parents-to-be incubate brown-, buff-, red-brown-, purple-blotched, speckled, 2.16- to 2.67-inch (55- to 68-millimeter) by 1.69- to 1.97-inch (43- to 50-millimeter) eggs for 28 to 35 days.

Bald eagles, bobcats, coyotes, crows, golden eagles, great horned owls, prairie dogs and skunks and drivers, feather-collectors, hunters and researchers jeopardize North American red-tailed hawk habitats.

Semi-helpless nestlings, active as two-day-old hatchlings, know a first, buff- or gray-white, long, silky down, a second, short, white, woolly down and, as 16-day-olds, first feathers. They learn food-pecking within one week, self-feeding and then finding separate nests within four to five weeks, flying within six weeks and foraging within seven weeks.

Red-tailed hawks, sexually mature as three-year-olds, mark as prey blackbirds, crows, grouse, gulls, nutcrackers, orioles, owls, pheasants, pigeons, thrashers, vireos and warblers and crabs and spiders. They also need chipmunks, cottontails, geckos, jackrabbits, lemmings, lizards, mice, moles, pikas, pocket gophers, prairie dogs, raccoons, rats, shrews, skunks, snakes, squirrels, toads, voles and woodchucks.

North American red-tailed hawks up to 10,498.69 feet (3,200 meters) above sea level offer winter's coldest temperatures at minus 10 degrees Fahrenheit (minus 23.33 degrees Celsius).

Alder, ash, aspen, beech, birch, cottonwood, cypress, elm, fir, gum, hemlock, hickory, juniper, larch, maple, oak, pine, red-cedar, redwood, spruce and sycamore protect red-tail life cycles.

Brown upperparts, brown-spotted and streaked white underparts, semi-banded gray-brown tails and yellow eyes qualify as juvenile hallmarks before the two-year-olds' richly browning plumage and reddening tails. Brown eyes and upperparts, dark-banded pale underparts, dark-barred wing undersides, rusty tails and yellow ceres, feet and legs reveal broad-, round-winged large-sized females and small-sized males. Circular soaring, slow-flapped flight on 44.88 to 52.36-inch (114- to 133-centimeter) wingspans suggests 17.71- to 25.59-inch (45- to 65-centimeter), 24.34- to 51.49-ounce (690- to 1,460-gram) adults.

North American red-tailed hawk habitats transmit hoarse, screaming kee-eee-arr calls by soaring adults, low, soft peeps by hungry youngsters and shrill chwirk vocalizations by courting adults.

illustration of eggs of red-tailed hawk subspecies of Buteo borealis; Illustrations of the Nests and Eggs of Birds of Ohio, Plate XLIV, figure 4, opposite page 170: Public Domain, via Biodiversity Heritage Library

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

North American red-tailed hawk (Buteo jamaicensis) at John Heinz National Wildlife Refuge, Philadelphia, southeastern Pennsylvania; January 2011: Mark Bohn/U.S. Fish and Wildlife Service, Public Domain, via USFWS National Digital Library @ https://digitalmedia.fws.gov/cdm/singleitem/collection/natdiglib/id/11638/rec/1

illustration of eggs of red-tailed hawk subspecies of Buteo borealis; Illustrations of the Nests and Eggs of Birds of Ohio, Plate XLIV, figure 4, opposite page 170: Public Domain, via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/34908293

For further information:

Audubon, John James. 1830. "Red-tailed Hawk. Falco borealis, Gmel." The Birds of America, From Original Drawings, vol. I (1827 to 30): plate LI (51). New York NY: J.J. Audubon; Philadelphia PA: J.B. Chevalier.
Available via Cincinnati Digital Library - The Public Library of Cincinnati and Hamilton County @ http://digital.cincinnatilibrary.org/digital/collection/p16998coll33/id/52/rec/53

Audubon, John James. 1840. "Harlan's Buzzard Buteo harlani, Aud." The Birds of America, From Drawings Made in the United States and Their Territories, vol. I: 38-40. New York NY: J.J. Audubon; Philadelphia PA: J.B. Chevalier.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/40382988

Baicich, Paul J.; and Colin J.O. Harrison. 2005. Nests, Eggs, and Nestlings of North American Birds. Second edition. Princeton Field Guides Book 35. Princeton NJ: Princeton University Press.

Bangs, Outram. 31 July 1901. "On an Apparently Unnamed Race of Buteo borealis: Buteo borealis umbrinus subsp. nov." Proceedings of the New England Zoölogical Club, vol. II (1900-1901): 68-69.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/12603593

Cassin, John. February 1855. "14. Buteo calurus, nobis." Proceedings of the Academy of Natural Sciences of Philadelphia, vol. VII (1854, 1855): 281. Philadelphia PA: Merrihew & Thompson.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/1694395
Available via HathiTrust @ https://hdl.handle.net/2027/hvd.32044093291839?urlappend=%3Bseq=307

Dickerman, R.W. (Robert W.). 1993. "Buteo jamaicensis suttoni." C.R. (Charles) Preston and R.D. Beane, "Red-Tailed Hawk." In A. (Alan) Poole, P. (Peter) Stettenheim and F. (Frank) Gills, eds., The Birds of North America, no. 52: 3. Philadelphia PA: American Ornithologists' Union.

Dickerman, Robert W. December 1994. "Undescribed Subspecies of Red-Tailed Hawk From Baja California." The Southwestern Naturalist, vol. 39 (4): 375-377.

Gmelin, Johann Friedrich. 1788. "74. Falco jamaicensis." Caroli a Linné Systema Naturae, tom. I, pars I: 266. Editio Decima Tertia, Aucta, Reformata. Lipsaie [Leipzig]: Impensis Georg Emanuel Beer.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/2896866

Gmelin, Johann Friedrich. 1788. "75. Falco borealis." Caroli a Linné Systema Naturae, tom. I, pars I: 266. Editio Decima Tertia, Aucta, Reformata. Lipsaie [Leipzig]: Impensis Georg Emanuel Beer.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/2896866

Grinnell, Joseph. 18 February 1909. "Birds and Mammals of the 1907 Alexander Expedition to Southeastern Alaska: The Birds: Buteo borealis alascensis, new subspecies." University of California Publications in Zoology, vol. 5, no. 2: 211-212.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/29393501

Grzimek's Animal Life Encyclopedia, 2nd edition. Volumes 8-11, Birds I-IV, edited by Michael Hutchins, Jerome A. Jackson, Walter J. Bock and Donna Olendorf. Farmington Hills MI: Gale Group, 2002.

Jones, Howard. 1886. Illustrations of the Nests and Eggs of Birds of Ohio. Illustrations by Mrs. N.E. Jones. Vol. II. Circleville OH: s.n. (sine nomine).
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/34908243

Nelson, E.W. (Edward William). 27 January 1898. "Descriptions of New Birds From the Tres Marias Islands, Western Mexico." Buteo borealis fumosus subsp. nov." Proceedings of the Biological Society of Washington, vol. XII: 7-8.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/3849871

Oberholser, Harry C. (Church). 4 November 1959. "A New Red-Tailed Hawk From Honduras: Buteo jamaicensis kemsiesi, new subspecies." Proceedings of the Biological Society of Washington, vol. 72: 159.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/34641938

Peterson, Alan P., M.D. "Buteo jamaicensis (Gmelin) 1788." Zoonomen: Zoological Nomenclature Resource > Birds of the World -- Current Valid Scientific Avian Names > Accipitriformes > Accipitridae > Buteo.
Available @ http://www.zoonomen.net/avtax/acci.html

Ridgway, Robert. 1874. "Buteo borealis, var. costaricensis Ridgway." In Baird, S.F. (Spencer Fullerton); T.M. (Thomas Mayo) Brewer; R. Ridgway. A History of North American Birds, vol. III: Land Birds: 285 note 1. Boston MA: Little, Brown, and Company.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/13183479

Storer, Robert Winthrop. 30 January 1962. "Variation in the Red-Tailed Hawks of Southern Mexico and Central America: Buteo jamaicensis hadropus new subspecies." Condor A Magazine of Western Ornithology, vol. 64, no. 1 (January-February): 78.
Available via SORA (Searchable Ornithological Research Archive) @ https://sora.unm.edu/sites/default/files/journals/condor/v064n01/p0077-p0078.pdf

Sutton, George Miksch; Josselyn Van Tyne. 23 September 1935. "A New Red-Tailed Hawk From Texas: Buteo jamaicensis fuertesi." Occasional Papers of the Museum of Zoology, University of Michigan, no. 321:1-6. Ann Arbor MI: University of Michigan.
Available via University of Michigan Deep Blue Data Repository @ https://deepblue.lib.umich.edu/bitstream/handle/2027.42/56760/OP321.pdf?sequence=1&isAllowed=y

Mallard Duck Habitats: Drab Female, Gaudy Male, Green Egg, Ground Nest

Summary: North American mallard duck habitats in Canada summers, Mexico winters get drab females, gaudy males from the United States' green eggs in ground nests.

female (right) and male (left) mallard ducks (Anas platyrhynchos); Flourtown, Montgomery County, southeastern Pennsylvania; April 19, 2008: Manjith Kainickara, CC BY SA 2.0 Generic, via Flickr

North American mallard duck habitats aid cultivators through the Anatidae family member's appetite for crustaceans, earthworms, insects and mollusks and hunters and naturalists through year-round distribution ranges from Canada southward into Mexico.

The mallard bears its common name and the scientific name Anas platyrhynchos as the French loan words for wild drake and the Latin for flat-nosed duck. Agro-industry, pesticides, pollution, predation, recreation, tourism and urbanization challenge round-, short-tailed mallard ducks, described in 1758 by Swedish zoologist Carl Linnaeus (May 23, 1707-Jan. 10, 1787). Arctic, subtropical or temperate, brackish, fresh- or salt-water, built or natural wetlands and sometimes open prairies draw mallards into flocks with same and territorially overlapping species.

Twenty-nine-year lifespans expect buildings, grasslands, ground-cover, tree crotches or holes and wetlands for food, nests and roosts even though mallards endure prairie potholes and roadside ditches.

February through September furnish opportunities for brooding six- to 16-egg clutches, followed by a second by feral pairs farther from North America's wild and urban interfaces.

Mothers-to-be give 4-inch- (10.16-centimeter-) deep, grass-, leaf-, reed-, sedge-lined nests inner 6- to 7-inch (15.24- to 17.78-centimeter) and outer 11- to 12-inch (27.94- to 30.48-centimeter) diameters. Nests with brown, white-centered, white-tipped down from maternal breast feathers house blue, blue-green, buff-green, gray-buff, green-tinged creamy, pale green or white, elliptical to subelliptical, waxy eggs. The last 1.97- to 2.56-inch (50- to 65-millimeter) by 1.26- to 1.77-inch (32 to 45-millimeter), smooth, unmarked egg initiates 22- to 29-day incubations for completed clutches.

Crows, eagles, falcons, fish, foxes, gulls, harriers, hawks, humans, magpies, martens, opossums, owls, raccoons, ravens, skunks, snakes, turtles and weasels jeopardize North American mallard duck habitats.

Downy nestlings hatched simultaneously from day-apart laid eggs know dark brown upper-parts, dark bill-eye-nape streaks, dark-marked ear-covert rears and yellow neck fronts and sides of heads.

Fast-functioning dark olive-brown bills, gray-brown feet and legs and open eyes quickly launch nestlings with yellow-patched back and rump sides and yellow-tipped wings into the water. Seven- to eight-week-old ducklings manage fledgling stages and yearlings with blue wing-patches, broad-based wings and white outer tail feathers, sexual maturity 47 to 48 weeks later. Adults need beetles, caddisflies, dragonflies, earthworms, fish eggs, flies, freshwater shrimp, grains, river-bottom and swamp grassy, herbaceous and tree nuts, roots, seeds and tubers, and snails.

North American mallard duck habitats up to 1,000-foot (304.8-meter) altitudes above sea level offer winter's coldest temperatures at minus 60 degrees Fahrenheit (minus 51.11 degrees Celsius).

Mallards prefer alfalfa, bushes, cattails, grasses, reeds and thickets alongside lakes, ponds, reservoirs and sloughs spring through fall and open grasslands, prairies and wetlands in winter.

Ashes, aspens, asters, baldcypresses, birches, bulrushes, cattails, cedars, cottonwoods, elms, grasses, hickories, junipers, oaks, sedges, sowthistles, sugarberries, sweetgums, sycamores, tupelos and willows qualify as camouflage vegetation. Females reveal mottled brown underparts and yellow-brown upper-parts and white neck-collared males black curly-feathered rumps, gray bodies rusty in summer and metallic heads grayer in summer. Fast, regular, shallow flight on 32.28- to 37.4-inch (82- to 95-centimeter) wingspans suggest 1.88- to 3-pound (0.85- to 1.36-kilogram), 19.5- to 2.6-inch (49.53- to 6.6-centimeter) adults.

North American mallard duck habitats transmit high-pitched courtship whistles and raspy raab calls from yellow-billed males and quack calls from dark-capped, dark-eyelined females' black-patched orange bills.

mallard duck (Anas platyrhynchos) nest with eggs; near Detroit Lake, Linn and Marion counties, northwestern Oregon; ; Sunday, May 15, 2005, 04:42:45: Oregon Department of Fish & Wildlife, Public Domain, via Flickr

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

female (right) and male (left) mallard ducks (Anas platyrhynchos); Flourtown, Montgomery County, southeastern Pennsylvania; Saturday, April 19, 2008: Manjith Kainickara, CC BY SA 2.0 Generic, via Flickr @ https://www.flickr.com/photos/manjithkaini/2426445603/

mallard duck (Anas platyrhynchos) nest with eggs; near Detroit Lake, Linn and Marion counties, northwestern Oregon; Sunday, May 15, 2005, 04:42:45: Oregon Department of Fish & Wildlife, Public Domain, via Flickr @ https://www.flickr.com/photos/odfw/4404568507/

For further information:

Baicich, Paul J.; and Harrison, Colin J.O. Nests, Eggs, and Nestlings of North American Birds. Second edition. Princeton NJ: Princeton University Press, Princeton Field Guides. 2005.

Brehm, Christian Ludwig. 1831. "4. Die grondlandische Stockente. Anas conboschas, Br. (Anas boschas, Linn.)." Handbuch der Naturgeschichte Aller Vögel Deutschlands, pages 865-866. Ilmenau, Germany: Bernh. Friedr. Voigt.
Available via MDZ (Münchener DigitalisierungsZentrum Digitale Bibliothek) Digitale Sammlungen @ http://reader.digitale-sammlungen.de/de/fs1/object/display/bsb11121761_00895.html

Grzimek's Animal Life encyclopedia, 2nd edition. Volumes 8-11, Birds I-IV, edited by Michael Hutchins, Jerome A. Jackson, Walter J. Bock and Donna Olendorf. Farmington Hills MI: Gale Group, 2002.

Linneaus, Carl. 1758. "17. Anas playrhynchos." Systema Naturae per Regna Tria Naturae, Secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis, Tomus I, Editio Decima, Reformata: 125. Holmiae [Stockholm, Sweden]: Laurentii Salvii [Laurentius Salvius].
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/727030

Peterson, Alan P., M.D. "Anas platyrhynchos (Linnaeus) 1758." Zoonomen: Zoological Nomenclature Resource > Birds of the World -- Current Valid Scientific Avian Names > Anseriformes > Anatidae.
Available @ http://www.zoonomen.net/avtax/anse.html