Life History
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Two species of vultures are present in Virginia: turkey vulture
(Cathartes aura) and black vulture
(Coragyps atratus). Vultures are in the family Cathartidae and
are related to storks and egrets.
Turkey vultures are large dark brown birds with wing spans up
to six feet and weigh about four
pounds (NWRC, unpublished data). Distinguishing characteristics
of turkey vultures are a bright
red head on adults, the leading edge on the underside of the wing
is black while the trailing edge
is gray, and the long tail extends well beyond the body when in
flight (Peterson 1980). Turkey
vultures have been reported to live to 16 years of age (Henny
1990). In contrast, black vultures
have less than a five foot wing span and average 4.6 pounds in
weight (NWRC, unpublished
data)(Peterson 1980). Adult and juvenile black vultures have dark
grey heads, the body is black,
the underside of the wings are dark grey to blackish with white
splotches at the end of the wing,
and the tail is relatively short (Peterson 1980) giving the appearance
of a large bat when flying.
Black vultures have been reported to live to 25 years of age (Henny
1990). The mode of flight
between black and turkey vultures differ due to different wing
lengths supporting about the same
body weight (Rabenhold and Decker 1989). Turkey vultures flap
the wings a few times and glide
when at low altitudes, whereas black vultures must flap constantly
interspersed with brief glides
when at low altitudes unless a strong wind blows. At high altitudes
both vultures fly by primarily
gliding and riding thermal wind currents.
Black and turkey vultures generally lay 2 eggs which are incubated
for approximately 40 days
(McHargue 1981). The young are fed and cared for by the adults
for two to three months before
fledgling (Jackson 1983). A post fledgling dependency period where
adults lead young to food
may exist for vultures (Rabenhold 1987, Jackson 1983). It is believed
that vultures nest annually.
Ecology
Turkey and black vultures are obligate scavengers (Rea 1983, Coleman
and Fraser 1987). The
diet consists of carrion, fish, and invertebrates (Rea 1983, Rabenhold
1987, Coleman and Fraser
1987). However, black vultures will kill other animals and tear
the animals apart for food (Roads
1936, McIlhenny 1939, Sprunt 1946, Lovell 1947, 1952, Parmalee
1954, Mrovsovsky 1971,
Lowney 1999).
Vultures roost in communal roosts, especially during late fall
through early spring since this
behavior enhances the ability to find food. Roosts may number
as few as 15 birds to over 1,000
(Prather et al. 1976, Lowney and Eggborn, unpublished data, J.
Fraser, VPI & SU, pers.
commun).
In North America, black vultures occur in the southeastern United
States, Texas, Mexico, and
parts of Arizona (Wilbur 1983). Black vultures have been expanding
their range northward in
the eastern United States (Wilbur 1983, Rabenhold and Decker 1989).
J. Bucknall (USDA, pers.
commun.) reported black vultures living in New Jersey and Pennsylvania
in 1995. Black vultures
are considered locally resident (Parmalee and Parmalee 1967, Rabenhold
and Decker 1989),
however some populations will migrate (Eisenmann 1963 cited from
Wilbur 1983). Turkey
vultures occur in all of Mexico, most of the United States, and
in the southern tier of Canada
(Wilbur 1983, Rabenhold and Decker 1989). Also, turkey vultures
continue to expand their
range into the northeastern United States (Wilbur 1983). Northern
populations of turkey vultures
migrate from summer to more southern wintering areas (Stewart
1977).
Coleman, J. S. and J. D. Fraser. 1987. Food habits
of black and turkey vultures in Pennsylvania and Maryland. J.
Wildl. Manage. 51:733- 739.
Lovell, H. B. 1947. Black vultures kill young
pigs in Kentucky. Auk 64:131-132.
Lovell,, H. B. 1952. Black vulture depredations
at Kentucky woodlands. Auk 64:48-49.
Lowney, M.S. 1999. Damage by black and turkey
vultures in Virginia, 1990-1996. Wildl. Soc. Bull. 27:715-719.
Mrovsovsky, N. 1971. Black vultures attack live
turtle hatchlings. Auk 88:672-673.
McHargue, L. A. 1981. Black vulture nesting,
behavior, and growth. Auk 98:182-185.
McIlhenny, E. A. 1939. Feeding habits of black
vulture. Auk 56:472-474.
Jackson, J. A. 1983. Nesting phenology, nest site
selection, and reproductive success of black and turkey vultures.
Pages 245 - 270 In Vulture biology and management. Eds. by S.R.
Wilbur and J. A. Jackson. Univ. Of CA Press. Berkeley.
Parmalee, P. W. 1954. The vultures: their movements,
economic status, and control in Texas. Auk 71:443-453.
Peterson, R. T. 1980. A field guide to the birds
east of the Rockies. Houghton Mifflin, Boston 384 p.
Henny, C. J. 1990. Mortality. Pages 140 - 151
In Birds of Prey. I. Newton, P. Olsen, and T. Pyrzalowski, eds.
Facts on File, NY, NY.240p.
Rabenhold, P. P. 1987. Recruitment to food in
black vultures: evidence for following from communal roosts. Anim.
Behav. 35:1775-1785.
Rabenhold, P. P. and M. D. Decker. 1989. Black
and turkey vultures expand their ranges northward. The Eyas. 12:11-15.
Rea, A. M. 1983. Cathartid affinities: A brief
overview. Pages 26 - 54 In Vulture biology and management. Eds.
by S.R. Wilbur and J. A. Jackson. Univ. Of CA Press. Berkeley.
Roads, K. M. 1936. Black vultures kill and eat
new-born lambs. Wilson Bulletin 48:219
Sprunt, A. 1946. Predation on living prey by the
black vulture. Auk 63:260-26.
Stewart, P. A. 1977. Migratory bird movements
and mortality rate of turkey vultures. Birdbanding 48:122-124.
Wilbur, S. R. 1983. The status of vultures in
the western hemisphere. Pages 113 -123 In Vulture biology and
management. Eds. by S.R. Wilbur and J.A. Jackson. Univ. Of CA
Press. Berkeley.
Additional life history information can be found at the Virginia
Fish and Wildlife Information Service Web page.
Turkey
Vulture
Black
Vulture
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