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NEW WORLD VULTURES Cathartidae |
- 7 species in New World
- DR personal total: 7 species (100%), 6 photo'd
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The
New World Vultures, or "cathartid vultures," are the carrion-eating
"buzzards" of the New World. They are similar in many ways to the 15
species of Old World Vultures (carrion-eating habits, bare heads,
strong bills, incredible powers of flight) but the two groups have
evolved separately from different ancestors. Indeed, the two sets of
vultures are among the best examples of convergent evolution (Griffiths
1994, Houston 1994). In the 1990s there were suggestions that New World
Vultures evolved from the stork lineage but newer molecular evidence
did not support that theory. The Cathartidae is now the only family
within the Order Cathartiformes (Johnson et al. 2016).
Black Vulture
(left) has adapted to most lowland habitats from the southern United
States to Tierra del Fuego. It is commensal with humans in towns and
cities. Greater Yellow-headed Vulture (above) is more specialized and restricted to lowland rain forest of South America. |
Among the seven species are some spectacular and specialized large birds. One of these is the King Vulture
— the two large birds in the roost shown below; one colorful adult and
one young bird above and to the left of the adult (the smaller ones are
the widespread Black Vulture). King Vultures are scarce across their
wide range across the primary forests and savanna of the Neotropics.
Adults are primarily white-plumaged with an incredible array of colors
on their bare heads and necks; the particular adult appears to have a
full crop (bare skin in center of breast). Young birds are all-black,
including the bare head. It is rare enough to see a King Vulture
gliding over the forest from afar, so that when I had this opportunity
to photograph these at a roost in southern Brazil, I was so delighted
that I crawled through the thick grass to get this shot, subjecting my
ankles to an attack of chiggers that still itched incessantly for many
month thereafter. |
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The two species of condor are the other headliners among cathartid vultures, and the créme de la créme is California Condor
(right). I was fortunate enough to see wild condors from Mt. Pinos and
several other southern California locales (an excellent resource for
the history of California Condor is Wilbur 1978) but by 1982 only 21
remained in the world. The decision was made to capture them all before
they went extinct. The last wild condor was netted in April 1987 for an
intensive attempt at captive breeding (after research on breeding
Andean Condors Vultur gryphus had occurred). Fortunately,
this massive effort — the most expensive and complex effort to save a
species ever undertaken — has been successful to date. The first
captive-born condors were released back into the wild in 1992 near the
Mt. Pinos area of southern California, and by 1998 the world population
(including captive birds) was 145. Efforts to re-introduce the condor
in its native range expanded to my home county — Monterey County — in
Dec 1997 & Jan 1999, when a dozen young birds were released, and
more each year thereafter. My photo (above) is one of those released
condor, bearing a wing tags and radio transmitter. |
Some
had to be recaptured, but others began ranging widely. The project
expanded to Pinnacles National Park just east of Monterey County. The
adult and young condor (photo left) were east of King City, and may be
moving between populations (the adult is below the young condor in this
photo).
In 2006 a pair attempted to breed in an huge redwood
stump; in 2007 a pair successfully fledged a young from a remote cliff
in the Ventana Wilderness. By 2018, about 170 were flying in
California, with more populations in Utah, Arizona, and Baja
California.
The
California Condors described to science by British naturalist George
Vancouver back in 1792 were foraging on dead whales on the shores of
Monterey Bay. It is now quite wonderful to watch a wild condor foraging
along the wild Big Sur coast! A dead Gray Whale that washed up in 2006
fed the entire local population for half-a-year (Roberson 2008, which
summarizes the reintroduction efforts to that date). This adult condor
(below) is scavenging a washed-up sea lion on the Little Sur River
beach. |
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The Turkey Vulture
photo (above) illustrates one typical cathartid vulture behavior:
wing-sunning. Many New World Vultures spend substantial time spreading
their wings — often early in the morning — which both serves
thermoregulatory functions and brings the plumage into good condition.
Vultures tend to forage most of the day, riding thermal to thermal but
searching for recently-dead meat over a wide range, but return to
communal roosts at night. You may be able to see one of the features
that separates New World Vultures from Old World Vultures in this above
photo: cathartid vultures lack any internal separation in the nostrils,
meaning that you can "see right through" the nostrils on the bill to
the scenery behind. [The other obvious difference in morphology is the
lack of a functional hind toe in cathartids; Houston 1994.] |
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Of
course, New World Vultures are well-known for their adaptations to
eating carrion: these two Turkey Vultures (above) are scavenging a dead
gull. New World Vultures are also fascinating for the specialization
and co-dependency of species within this family. The huge condors —
California Condor in North America and Andean Condor in western South
America — plus the King Vulture of the Neotropics, could not exist
without contemporaneous small vultures of the genus Cathartes.
Only these small vultures have a highly-developed sense of smell —
ranking them with kiwis and some petrels in this ability. As
dramatically shown in the BBC's video series "Life of Birds with David Attenborough",
a Turkey Vultures has a remarkable ability to locate recently-dead
mammals using nothing but their sense of smell. This ability is shared
by the Lesser Yellow-headed and Greater Yellow-headed vultures of the
Neotropics. The big vultures (King Vulture and the condors), with great
eye-sight but poor smell, rely primarily on the small vultures to find
carrion. The big bruisers then "take-over" the carcass for their fill,
but at the same time specialize on skin, tendons, and other tough meat
less readily eaten by the small cousins.
Black
Vultures also lack a good sense of smell, but feed more on easily-found
offal, such as dead fish on shorelines or at man-made dumps. My photo
(below) shows three species of small vultures lined up on a fence (from
left to right: a Lesser Yellow-headed Vulture, a Black Vulture, and two Turkey Vultures).
This shot was taken in the Pantanal of Brazil where the resident Turkey
Vultures have a conspicuous white patch on the nape, quite different
from the highly-migratory red-naped North American birds. |
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Photos: The Greater Yellow-headed Vulture Cathartes melambrotus was in flight over the Brazilian Pantanal on 21 July 2010. The Black Vulture Coragyps atratus was near Lima, Peru, on 26 Nov 2014. The roost of King Vulture Sarcoramphus papa
and Black Vultures was taken in the Serra das Araras, Mato Grosso,
Brazil, on 4 Aug 1999 — this particular roost contained ten King
Vultures and dozens of Blacks. The California Condor Gymnogyps californianus
was in flight along the Big Sur coast of California on 25 Feb 2010; the
circling adult and immature were east of King City, Monterey Co., CA,
on 20 Mar 2015, and the adult condor on Little Sur River beach was
taken 18 Feb 2018. The wing-drying Turkey Vulture Cathartis aura was at Pebble Beach on 30 Mar 2018, and the two scavenging a gull were at Big Sur R. mouth on 17 Feb 2007. The Lesser Yellow-headed Vulture Cathartis burrovianus on a fence with Black and Turkey Vultures was in the Pantanal of Mato Grosso, Brazil, in Aug 1999.
All photos © Don Roberson; all rights reserved.
Bibliographic note: Photos: There is no "family book" per se but an excellent introduction to this family is in Houston (1994).
Literature cited:
Griffiths, C. 1994. Monophyly of the Falconiformes based on syringeal morphology. Auk 111: 787–805.
Houston, D. C. 1994. Family Cathartidae (New World Vultures), pp. 24–41 in del Hoyo, J., A. Elliott, & J. Sargatal, eds. Handbook of the Birds of the World. Vol. 2, Lynx Edicions, Barcelona.
Johnson,
J.A., J.W. Brown, J. Fuchs, and D.P. Mindell. 2016. Multi-locus
phylogenetic inference among New World Vultures (Aves: Cathartidae).
Molec. Phylog. Evol. 105: 193–199.
Roberson, D. 2008. California Condor: Ice Age icon adapts to modern World, pp. 28–35 in Rare Birds Yearbook 2009 (E. Hirshfeld, ed). BirdLife International, Shropshire, U.K.
Wilbur,
S. R. 1978. The California Condor 1966-76: A Look at its Past and
Future. North America Fauna 72. U. S. Fish & Wildlife Serv.,
Washington, D.C.
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