NEW AND OLD WORLD VULTURES
Stretch out your arms at your sides as far as they will go. Close your eyes and delicately wiggle your right fingers. Imagine this slight gesture allows you to turn in a perfect circle as you soar high in the air, your enormous wings outstretched. You can glide for hours effortlessly, on an updraft's slight breeze. You are a vulture. Vultures are among the most beautiful fliers on earth.
Vultures might be described as transcendent creatures. They can sail for hours on thermals as they survey the ground far below with their acute eyesight. Vultures clean the earth, rather than destroy it, preventing the spread of disease and clearing away evidence of violence and death from a landscape. Vultures diet on the dead, rarely killing other animals when foraging for food. These mysterious birds have been emblazoned on the walls of Egyptian pyramids, and featured in the ancient texts of the Mayans.
And yet, among humans, vultures have a bad name. Could it be their love of carrion and sanitary landfills? Because their preferred method of defense is to vomit on their attackers? Because they urinate on themselves in order to kill carrion-borne bacteria on their legs? Because they have been found on battlegrounds feasting on the bodies of the fallen? Or is it because vultures' wrinkled faces, dark wings, ruffled pale neck ruffs and bald heads make them look like old monks skulking around a garbage pile?
Whether you choose to view these contradictory creatures as beautiful or hideous, they are ubiquitous. In America, vultures can be found adorning the trees and fields of many national and state preserves -- and also parading across trash heaps, cavorting in children's playgrounds, lining the trees of gated suburbs and clinging to the tops of supermarkets. They hang around in committees (the name for a group of vultures), just about anywhere.
OLD AND NEW WORLD VULTURES
Vultures come in two varieties -- New World vultures, which are grouped together with condors and found in both North and South America -- and Old World vultures, which inhabit Africa, Europe and Asia. According to the London Natural History Museum's Birds: A Complete Guide to Their Biology and Behavior, New and Old World vultures are a perfect example of convergent evolution.
New and Old World vultures share countless common features -- most notably, they are scavengers, dieting primarily on carrion -- an attribute that is singular among vertebrates. Both New and Old World vultures have unusually powerful distance vision and are high fliers that enjoy sailing on thermal air currents. Vultures in both groups have bald heads, curved and hooked beaks and feet adapted for walking on land rather than for seizing prey.
Nonetheless, Old and New World vultures are not related through any direct genetic connection. Old World vultures belong to the family Accipitridae, which also contains eagles, hawks and kites. New World vultures have a less certain classification. They are viewed as being more closely related to storks, and have been located most recently in their own family, Cathartidae.
Despite their different classifications, both Old and New world vultures serve the important function of providing clean-up and sanitation services within a given ecosystem. In areas where vultures die off, other mammals such as dogs may move in to eat carrion; rates of serious illnesses such as rabies consequently may increase significantly.
This is in part because New and Old World vultures share another fascinating feature. Their stomachs produce potent acids that kill bacteria that carry diseases -- among them, cholera, anthrax and salmonella. Thus, vultures prevent the spread of disease to other animals in our ecosystem, including livestock and humans.
NEW WORLD VULTURES
In Florida and much of the United States, there are two principal species of New World vultures -- the turkey vulture and the black vulture. These birds are often found feeding together, sometimes in the company of raptors such as eagles.
The turkey vulture is the larger of the two common American vultures; its wingspan can stretch as wide as six feet. The turkey vulture derives its name from its red, wrinkled head, reminiscent of a turkey's head and wattle.
Turkey vultures, often called turkey buzzards, are widespread throughout the continental United States. These birds fly with their wings held aloft in a V-shape, a trait that helps distinguish them from afar from black vultures, hawks and eagles.
Turkey vultures are exquisite fliers. On land, they are less graceful. They run with a comical, loping gait and perform ungainly mating rituals. A 1938 Cornell Ph.D. thesis by V.C. Coles reported that during their earthbound mating rituals, male turkey vultures hold their wings high above their heads, inflating their necks and throat air sacs, while groaning and yapping, rocking side to side, lifting their feet in the air and jumping up and down.
Turkey vultures prefer open spaces, such as pastures and farmland, located near forest edges. In Florida, turkey vultures are a common sight in federal and state parks with swampland habitats. These birds tend to congregate on dry banks along the edges of swamp water, although ornithological studies have reported that turkey vultures sometimes wade belly-deep in water to bathe or even to feed. Unlike black vultures, turkey vultures travel and forage in offshore island habitats as well as in inland areas.
According to the Audubon Society's The Sibley Guide to Bird Life and Behavior, black and turkey vultures vary in their flying styles. Turkey vultures are stronger fliers than black vultures and are able to lift themselves from the ground more easily. Turkey vultures rise early in the morning before thermal updrafts have formed in the sky. The vultures hunt low to the earth, depending on smell as well as acute eyesight to locate food, and are adept at foraging in the thick brush of forests.
Turkey vultures have the most highly-developed sense of smell of all vultures, and are able to detect carrion from as far as five miles away. If you look closely at a turkey vulture, you will see that it has a prominent hole just above its beak, as shown at right. The hole is enclosed by a bony structure that covers the bird's nares (nostrils) and prevents debris from entering them as it feeds, thus safeguarding the vulture's smelling apparatus.
Turkey vultures rely almost completely on scavenging for carrion. Occasionally, however, they do eat live animals. The Sibley Guide to Bird Life & Behavior reports that turkey vultures have been observed feeding on heron nestlings.
Few animals prey on turkey vultures. Bald eagles sometimes steal food from them, although these two species can be spied in Florida habitats coexisting peacefully and foraging side-by-side. Raccoons, opossums and foxes sometimes steal turkey vulture eggs, which are vulnerable because they are laid on low surfaces, rather than guarded high above the ground in treetop nests.
Turkey vultures do not build nests: instead they lay eggs in holes in trees, under rocks, or in deserted buildings. Although individual birds may forage for food solitarily, when turkey vultures roost, they often do so communally, in large congregations. They are believed to mate for life.
Turkey Vulture ID Information: Turkey vultures are predominantly dark, with blackish-brown feathers on their bodies and wings. They have well-defined wing-tips (primary feathers) that look like long fingers. The feathers on the undersides of turkey vultures' wing-tips and the on the back edges of their underwings are a light grayish-brown. Turkey vultures' legs are reddish, their eyes are dark gray, and their bills white and hooked with sharp points. Although adult turkey vultures have red heads, juveniles have gray heads and are often confused with black vultures. Turkey vulture eggs are white with brown-and-lavender blotches. Uncommon sightings of albino turkey vultures have been reported.
Click on images to enlarge.
A turkey vulture
Two black eagles, two turkey vultures and a black vulture communing on a warm afternoon
Head of an adult black vulture
On nearly any day, winter or summer in rural Florida, you can spy black vultures circling through the sky, singly or in groups of anywhere from five to twenty birds. Black vultures are smaller the turkey vultures, but still have impressive wingspans, reaching as wide as 5 feet, 5 inches. Black vultures lack the red faces of turkey vultures.
In flight, black vultures' legs project awkwardly behind their bodies, because their tails are short. When approaching the ground, their legs tend to dangle beneath them inelegantly. They run with a clumsy hop-step like a hobo with a game leg fleeing a trainyard guard. Nonetheless, once airborne on updrafts, black vultures are nimble and tireless fliers.
Black vultures tend to fly later in the day than turkey vultures, usually waiting until afternoon thermals have formed in the sky. They soar at somewhat higher altitudes than turkey vultures, often in large numbers. When not gliding, black vultures flap their wings rapidly in flight.
From high aloft, black vultures rely on their prodigious eyesight to locate prey. Although they often roost in woodland trees bordering open fields and swamps, black vultures lack the turkey vulture's extraordinary sense of smell and thus avoid foraging in woodland areas where prey may be hidden behind foliage. Black vultures prefer open areas where carrion is easily observable. When food is not visible from above, black vultures sometimes rely on turkey vultures to lead them to sites where carrion is available.
Black vultures are both more aggressive and more gregarious than turkey vultures. They circle in larger numbers high in the sky and tend to gather on the ground in bigger groups, crowding out turkey vultures at carrion sites. Black vultures are more likely to approach humans in locations such as campgrounds and dumps, in attempts to snatch food when people's heads are turned. There have been reports of black vultures being bold enough to enter people's kitchens in order to snatch food off the tables.
Although black vultures prefer carrion, the Peregrine Fund reports that they have been observed eating fruits such as bananas, palm fruits, coconuts and avocados. Black vultures also have been documented consuming live food such as baby turtles and badly-wounded or newborn livestock. You are far more likely, however, to find black vultures clearing landscapes of unsavory and smelly debris -- gathering around roadkill or sorting through landfills or picking through debris near picnic-area garbage cans.
Black vultures seem created to be paradoxical creatures, bent on cleaning the earth while remaining markedly oblivious to the frills of personal vanity and hygiene. Despite the antiseptic qualities of their bodily excretions, black vultures often have an admittedly dirty appearance, as might be observed, for example, in the photo shown here of the black vulture preening, its beak carefully separating its breast feathers while its wings remain covered with filth.
Like turkey vultures, black vultures do not build nests. Instead they look for smooth level surfaces, on rocks or even on the ground. They produce two offspring each year. The fledglings fly at the age of three months, but remain in social groups with their parents for years.
Black vultures are found throughout the Americas, from the Northeastern United States through South America. They were portrayed hundreds of years ago in the codices of the ancient Mayans of Mexico, where black vulture glyphs were associated with symbols of death and birth and depictions of human sacrifices.
Black vultures are the sole vulture species in the United States protected by the Migratory Bird Treaty Act of 1915. Although many black vultures do not migrate, those in the northernmost part of the birds' range may relocate to warmer regions during the winter. The Migratory Bird Treaty Act forbids the poisoning, shooting and trapping of black vultures, among other migratory birds, and the sale of vulture parts or feathers.
Black Vulture ID Information: Black vultures are birds composed in black and white, without ornamental colors: they have black bodies, dark gray legs and black-and-white wings. Adult black vultures have black heads, while juveniles' heads are dark gray. Only the vultures' dark reddish-brown eyes show a hint of color. From a distance, when soaring high in the air, black vultures are most easily identified by their short tails and the white feathers on their outer wings. The eggs of black vultures are pale green and marked with brown splotches.
Ancient Mayan glyphs of the zopilote or black vulture.
OLD WORLD VULTURES
Cape Griffon Vultures
Julius Arinaitwe, Africa Program Director of BirdLife International, has described Africa's large vultures as "iconic" and "spectacular". An example is the majestic Cape Griffon vulture, the heaviest and third largest of all Old World vultures. Adorned with a luxurious array of light and dark-brown feathers, downy beige collars and luminous brown eyes rimmed with blue, Cape Griffons vultures can weigh up to 25 pounds and have wingspans reaching 81/2 feet. They fly tens of thousands of feet in the air, often in large groups that form "nets" across the sky as they scavenge for food on the earth below.
These impressive creatures can be viewed any day of the year at the St. Augustine Alligator Farm, a Florida zoological park that breeds Cape Griffon vultures for conservation purposes. In most years, the Cape Griffon vultures at the Alligator Farm produce new offspring. When their eggs are laid, Alligator Farm staff remove them from the birds' nests, replacing them with imitation eggs. The staff then incubate the eggs, caring for them carefully until they hatch. When the hatchlings are a few days old, they are transferred back to their parents, who take them in as if unsurprised by their eggs' seamless transformation into live offspring.
The wild Cape Griffon vulture is native to south and southwestern Africa, and has become vulnerable to extinction as a result of habitat loss and human activities. According to BirdLife.org, large African vultures are killed frequently in collisions with power lines and wind turbines; drawn to poisoned baits set by farmers to kill other animals that prey on livestock; and deliberately targeted by poachers who fear that vultures' presence can alert authorities to illegally slaughtered big game. African vultures are also hunted unlawfully by traffickers for their body parts, which are believed by some to have medicinal properties.
In the wild, Cafe Griffon vultures build stick nests on the ledges of cliffs, in colonies that can number more than a thousand birds. The vultures lay only one egg each season. Eggs incubate for 55 days, and both male and female vultures care for the hatchlings, which take approximately 140 days to fledge. The species trait of laying a single egg and Cape Griffon vultures' dependence on specialized habitats has made them particularly vulnerable to encroachments on their natural habitats. Current conservation efforts focus both on protecting the birds in the wild and on breeding them in sheltered environments. Cape Griffon vultures are currently classified as "endangered".
These birds are worth a visit to the Alligator Farm, a site already well-known for its native-bird rookery as well as its crocodilians: Cape Griffon vultures are both regal and melodramatic. They engage in courtly dances on hot days; squabble frequently; and also consume prodigious amounts of food.
During feeding time at the Alligator Farm, aggressive native black vultures often descend to reap the benefits of the Cape Griffon vultures' meals. Alligator Farm staff frequently scare off the black vultures until the Old World vultures have had a chance to finish their meals. This interaction suggests that despite Cape Griffon vultures' considerable size, New World black vultures, when gathered in large numbers, are more than a match for their Old World counterparts.
Click images to enlarge.
Hooded Vulture (Necrosyrtes monachus)
Not all Old World vultures are as majestic and ponderous as the Cape Griffon vulture. The African hooded vulture, for example, is a small species, barely larger than a medium-sized turkey. The hooded vulture is relatively timid: hooded vultures tend to hang back and allow larger Old World vultures to tear apart carrion. The hooded vultures then move in and take smaller bites with their long, sharp beaks.
Hooded vultures are striking birds, with chocolate-brown feathers; pink faces and necks; and eyes ringed with blue. Fluffy white feathers mottled with brown spots encase the vultures' legs. Dense downy feathers rim the vultures' faces in a hood-like shape that gives the species its name. Juveniles have pale blue faces with dark markings and dark brown hoods. According to IUCN (the International Union for the Conservation of Nature), hooded vultures have conspicuous earholes and sit in a characteristic hunched posture, with their wings drooping. They run no taller than 27 inches high, although their wingspans may reach nearly 6 feet.
Once common, this species is now listed as critically endangered by the IUCN. Avian influenza, poisoning by pesticide, habitat loss and killings by poachers have reduced the birds' numbers significantly. According to the IUCN, 90% of all vulture parts sold on black markets come from hooded vultures.
Like the Cape Griffon vultures shown above, captive hooded vultures are housed for conservation purposes at the St. Augustine, Florida Alligator Farm, where they can be viewed easily. Breeding these birds in captivity is tricky. Hooded vultures lay a single egg each breeding season, and their eggs take 48-54 days to hatch. The chicks require another 89-130 days to fledge and remain dependent on their parents for another 3-4 months.
In their natural habitat, hooded vultures appear in savanna grasslands, open woodlands and forest edges. In urbanized areas, hooded vultures con-gregate in clearings and vacant lots. They feed on both carrion and insects.
Face of an adult African hooded vulture
Click on images to enlarge.
Younger vultures have beaks that are completely dark.
A Cape Griffon vulture
RECOMMENDED CITATION FOR THIS PAGE:
Sharp Paula and Ross Eatman, "New and Old World Vultures." Birds of the Florida Swamps. April 14, 2018. Web. [Date accessed] <>
All images and text are (c) Copyright 2018 Paula Sharp & Ross Eatman. See Permissions.