A number of North American bird species feed on dead animals. Bald Eagles and Crested Caracaras come to mind.
However, the best-known carrion eaters are the vultures.
There are three species of vultures you can find in North America;
- Turkey Vulture
- Black Vulture
- California Condor
For all three North American species — Turkey Vultures, Black Vultures, and California Condors –carrion rules.
Although sometimes mistaken for hawks or eagles, vultures are more closely related to storks. Like storks, they belong to the order Ciconiiformes.
Hawks and Eagles belong to the order Falconiformes. Both behavior and DNA studies bear out North American vultures’ relationship with storks. Their affinity with other vultures of the world is less clear.
The vulture species in North America are known as New World vultures.
Old World vultures differ in many ways. For example, New World vultures don’t build nests, don’t truly vocalize, and don’t nest in colonies. Old World vultures do.
One thing all vultures (New World and Old World) share is a featherless neck and head. It’s an important adaptation, given how vultures get their food. Rotting carcasses foul feathers.
Different Types of Vultures
Let’s have a look at the different types of vultures in North America
Turkey Vultures are the most widespread of North American vultures. They stand alone in their ability to find food by smell. This talent allows them to search for carrion where other species can’t.
California Condors and Black Vultures must rely on their sense of sight. So finding food in forested areas, for example, poses a challenge. Research has shown that Turkey Vultures can find dead chickens hidden on a forest floor.
Occasionally, Turkey Vultures will prey on living animals, such as nesting herons.
Of the three North American vultures, Turkey Vultures are the best at soaring. Like Black Vultures and California Condors, they search for food mostly on the wing. However, their light wing-loading gives them better lift.
It also allows them to take advantage of weaker thermals. They don’t have to wait so long for the atmosphere to warm. This means they can get out earlier than other vultures to feed.
Adult Turkey Vultures of both sexes have a small, bare redhead. Seen from below, their body and forewings are black. For the most part, the wings appear gray. The wingtips are silvery. From above, these birds appear uniformly brown to brownish-gray.
During their first year, juvenile Turkey Vultures have a dark gray head. So, for a few months, they could be mistaken for Black Vultures when perched.
Turkey Vultures range throughout the U.S. and Mexico and into southern Canada. Often, they’re seen soaring together in small or large columns. They also roost in groups.
Black Vultures have a slightly shorter body and considerably shorter wingspan than Turkey Vultures.
Like Turkey Vultures, they tend to soar and roost in groups. Because they depend on sight to locate carcasses, they soar at considerable heights.
In addition to their dark gray to black-head, Black Vultures show a large whitish patch at the end of their wings. Viewed from below, the patch stands out against the otherwise black body and wings.
Adult and juvenile Black Vultures are identical, except for a grayer head in adults.
Black Vultures appear year-round throughout the southeastern U.S., as far north as New Brunswick along the East Coast and west through southern Missouri, Texas, extreme south-central Arizona, and much of Mexico.
After almost disappearing from the face of the earth, California Condors have made a comeback.
However, their range remains limited. Small populations can be found in Southern California, northern Baja California, and Arizona around the Grand Canyon.
Only human efforts have managed to rescue this enormous bird (wingspan: 109 inches) from extinction. Condors can be mistaken for small airplanes from a distance because of their size and ability to glide steadily for long distances.
Unlike other North American vultures, California Condors show considerable variation between juveniles and adults. Juveniles have gray heads and some light gray on otherwise dark gray wings in flight.
Their heads turn pink during the third year and orange by the fifth summer. Adults have large white patches on the wings when viewed from below.
Their head is orange. From above, they are dark gray to black. Narrow bands of white backed by lighter gray appear on the wings. When they’re courting, the head of California Condors turns deeply red-pink. This color change also happens when the birds are alarmed.
How Vultures Breed
California Condors put on the most elaborate courtship among North American vultures.
Weeks before the eggs are laid, the male and female begin pair flights.
The tips of their wings almost touch as they glide close together. Back on earth, as a courting display, the male stands tall, spreads his wings, struts, and bobs his head.
Vulture pairs are monogamous and remain together long-term. If one of the pair dies, the other might mate again.
North American vultures nest in caves and cliff crevices, hollow trees. In Florida, some vultures nest on the ground in stands of palmetto. Sometimes, they choose human-made structures. Nest sites are often used over again for years.
Close to the nest, all three vulture species remain apart from other vultures, However, they will socialize away from their nest and forage together. They first breed when they’re six to eight years old.
California Condors make some attempt at shaping a nest. Black Vultures and Turkey Vultures do not. The single blue-green California Condor egg has no markings.
The vultures lay one to four eggs, dull-white or tan, with darker markings. For Black Vultures and Turkey Vultures, incubation requires 35 to 40 days.
California Condor eggs take eight weeks. Black and Turkey vultures produce one brood a year. California Condors breed every other year.
When vulture chicks hatch, they’re heavily downed. Black and Turkey vulture fledging occurs at eight to 13 weeks. California Condors take around six months. Condor fledglings are dependent on their parents for as much as a year.
Vulture Feeding Behavior
For Black Vultures and Turkey Vultures, food would seem to abound.
They can find it along roads, in landfills, on farms, and anyplace else with carrion. Black Vultures will eat baby turtles and even newborn calves as well as picnic food left available by campers.
California Condors have been known to search farms and ranches in southern California for food.
Vultures aren’t above following and watching each other to see who finds food first. Because Turkey Vultures are out early looking for carrion, Black Vultures or California Condors will keep an eye out to see what they’ve found.
What can follow is a feeding frenzy of sorts with several species participating. At this point, a dominance hierarchy sets up. In the west, if Golden Eagles get involved, they’ll dominate California Condors.
Condors, on the other hand, will dominate Turkey Vultures. In the eastern U.S., Black Vultures dominate Turkey Vultures.
California Condors, Turkey Vultures, and Black Vultures have strong beaks. They use them to tear meat from a carcass as they use a foot to hold it down. When they come across a tough carcass, two of them pull the meat apart. To feed their young, vultures carry food to the nest in their crop and regurgitate it.
Some Interesting Facts About Vultures
A Group of Black Vultures or Turkey Vultures is called a cast, committee, meal, vortex, and wake of vultures. A group of California Condors is known as a condo and a scarcity of condors.
New World vultures often perch with spread wings. It’s thought they do this to dry dew from their feathers and warm their body. Also, soaring can misshape their feathers, and the behavior might help realign them.
California Condors declined to fewer than 20 individuals in the wild by the early 1980s. Lead bullet fragments in the carrion they ate were a prime suspect.
Capturing all the wild condors saved the species. By 2000, their population had increased to more than 165. Sixty-six condors were released into the wild between 1992 and 1998. However, lead poisoning continues to kill the birds even now.
Black Vultures and Turkey Vultures have expanded their range despite threats. Ranchers have trapped them because they attack newborn calves.
Current practices in forestry have reduced Black Vultures’ nesting sites in hollow logs. Carcasses on ranches and farms are fewer because of improved sanitation. But roadkill seems to be more than replacing any food deficit in some areas.
It’s thought that wild adult North American vultures’ annual survival rate is 75 to 90 percent.
The oldest California Condor on record lived to be 45 years old.
Vultures defecate down their legs so the liquid in the feces cools them as it evaporates. The feces accounts for their whitish legs and feet.
Perhaps not surprisingly, caves where vultures nest year after year take on a powerful odor.
Giving Credit to Vultures
North American vultures help keep the continent clean. They thrive on fresh carcasses as well as those that have undergone advanced putrefaction. They’re endowed with a powerful immune system.
The microbes and toxins they consume would quickly kill a human. In-flight, when they’re out searching for carrion, they soar grandly, adding beauty to the skies.
If nothing else, Black Vultures, Turkey Vultures, and California Condors deserve a little gratitude. They do a job only people with a strong stomach would take on.
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