Sunday, January 23, 2011

North American Black Vulture Habitats for Black Bodies From Pale Eggs


Summary: North American black vulture habitats pull black-bodied, white-tipped, yellow-billed raptors from pale eggs in caves, logs, stumps, thickets or on cliffs.


North American black vulture in southern Florida's Everglades National Park, Feb. 27, 2006: Everglades NPS (evergladesnps), Public Domain, via Flickr

North American black vulture habitats anger ranchers who accuse the condor family member of accessing eggs and newborns but appease environmentalists and naturalists who appreciate Mother Nature's year-round carcass-seeking, carrion-eating clean-up crew.
Black vultures bear the common name American black vulture and the scientific name Coragyps atratus (crow-raven clothed in black) as black-bodied native raptors of the Americas. Angry ranchers, forest fire-destroyed tree cavities and pesticide-thinned eggshells challenge black vultures, described in 1793 by German naturalist Johann Matthäus Bechstein (July 11, 1757-Feb. 23, 1822). Communal roosts draw together the extended families of the broad-winged, gray-footed, gray-headed, gray-legged relative of Andean and California condors and of king, turkey and yellow-headed vultures.
Twenty-six-year lifespans entertain 3.73-mile (6-kilometer) feeding ranges and 39,442.06-acre (5,962-hectare) summer and 36,771.75-acre (14,881-hectare) winter mean home ranges up to 9,186.35-foot (2,800-meter) altitudes above sea level.

January through August furnish opportunities for brooding a first one- to three-egg clutch, with a second three to four weeks after failure from predation or weather.
Monogamous parents-to-be gather eggs amid palmetto, sawgrass and yucca thickets or tree roots, onto cave shelves or cliff ledges, under boulders or within logs or stumps. Egg-depositing happens at two-day intervals at 8- to 10-foot (2.44- to 3.05-meter) heights for non-glossy, oval to elliptical, smooth, 2.98- by 2.01-inch (75.6- by 50.9-millimeter) eggs. It involves both parents in 28- to 39-day incubations of blue-white, dull white or gray-green eggs blotched or spotted with chocolate or lavender clusters or wreaths.
People and weather jeopardize North American black vulture habitats whose distribution into Mexico joins the Brazilian subspecies, whose mountain ranges join those of the Andean subspecies.

Bare-headed, downy, semi-helpless nestlings with creamy-buff bodies and red-tinted upper-parts keep to their birthing places under both parents' care for the first eight weeks of life. They live on regurgitated food from their parents even though they leak everything from both ends before letting their heads sink between their wings when alarmed. They manage activities within 10 days, full growth within eight weeks, feathering and flights 11 weeks after hatching and independent life cycles as 14- to 18-week-olds. They need bald cypress, hickory, juniper, oak, pine and sycamore stands, clean water sources and thermal air currents for communal roosts, internal hydration and soaring flights.
Black vulture habitats offer summer and winter temperatures respectively below 85 degrees Fahrenheit (29.44 degrees Celsius) and above minus 10 degrees Fahrenheit (minus 23.33 degrees Celsius).

Lowland forests and open woodlands provide communal roosts while landfills and roadsides present bright-colored cloth, glass and plastic for nesting- and roosting-place decorations and food sources.
Sharp sight and soaring flight on choppy, quick, shallow wingbeats and flat-winged glides qualify as survival skills for nesting and roosting scent-challenged, square-tailed, weak-legged black vultures. They reveal the 4.5- to 5-foot (1.37- to 1.52-meter) wingspan and the strong-muscled eyes of the somewhat iridescent, 24- to 27-inch- (60.96- to 68.58-centimeter-) long scavenger. Lack of a syrinx stops the 3.5- to 5-pound (1.59- to 2.27-kilogram) vulture's yellow-tipped gray bills from sounding out anything other than barks, grunts and hisses.
Governmental tardiness in roadkill removal and motorist tendencies toward roadside litter turn urban and wilderness interfaces into "Scavengers Wanted" niches within North American black vulture habitats.

Coragyps atratus egg in Egg Collection at Museum Wiesbaden, Hesse state, central western Germany: Klaus Rassinger and Gerhard Cammerer, CC BY SA 3.0, via Wikimedia Commons

Acknowledgment
My special thanks to:
Talented artists and photographers/concerned organizations who make their fine images available on the Internet;
Virginia Polytechnic Institute and State University for superior on-campus and on-line resources.
Image credits:
North American black vulture in southern Florida's Everglades National Park, Feb. 27, 2006: Everglades NPS (evergladesnps), Public Domain, via Flickr @ https://www.flickr.com/photos/evergladesnps/9103751408/
Coragyps atratus egg in Egg Collection at Museum Wiesbaden, Hesse state, central western Germany: Klaus Rassinger and Gerhard Cammerer/Wiebaden Museum, CC BY SA 3.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Coragyps_atratus_MWNH_0717.JPG

For further information:
Baicich, Paul J.; and Harrison, Colin J.O. 2005. Nests, Eggs, and Nestlings of North American Birds. Second Edition. Princeton NJ: Princeton University Press, Princeton Field Guides.
Bechstein, Johann Matthäus. 1793. Johann Lathams allgemeine Uebersicht der Vögel, vol. I, anhang: 655. Nuremberg: Adam Gottlieb Schneider and Johann Christoph Weigel.
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.
Peterson, Alan P., M.D. "Coragyps atratus (Bechstein) 1793." Zoonomen: Zoological Nomenclature Resource > Birds of the World -- Current Valid Scientific Avian Names > Cathartiformes > Cathartidae > Coragyps.
Available @ http://www.zoonomen.net/avtax/cath.html


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