Vultures possess a repertoire of repugnant behaviors. They engage in the repulsive act of urinating on themselves for the purpose of maintaining a cool body temperature. Additionally, they exclusively feast upon putrid carcasses teeming with bacteria, delving their bare heads into the flesh to tear it apart, and even resort to regurgitating their meals to escape from predators.
Nevertheless, these revolting habits serve as ingenious adaptations that enable vultures to survive and fulfill the crucial role of environmental cleanup on our behalf.
The act of self-urination in vultures not only aids in cooling their bodies but is also believed to eliminate bacteria present on their legs, which they acquire while traversing deceased animals.
The baldness of vultures’ heads prevents their feathers from becoming matted with blood when they thrust their heads into carcasses to access the flesh. Due to their feeble legs and inadequately strong talons, vultures rely solely on their robust beaks to tear and shred their food.
Vultures possess remarkably potent stomach acid, making them one of the few species capable of safely consuming bacteria-ridden carcasses that would otherwise be harmful or fatal to other creatures. In doing so, they help eradicate detrimental bacteria from the environment, including botulism and anthrax.
The act of vomiting serves as an escape mechanism for vultures, allowing them to become lighter for takeoff when they overindulge and become excessively heavy. Moreover, it serves as a diversionary tactic against potential threats.
Although vultures lack vocal organs for melodic songs, they can emit deep hisses or grunts, particularly when startled or competing for space near a carcass.
There exist 23 vulture species worldwide, with three of them inhabiting North America. If you hold an interest in raptors, I recommend exploring a comprehensive guide to hawks native to North America.
This guide provides valuable information on identifying the various vulture species found in North America, as reported by avibase and gathered from observations made by bird enthusiasts through ebird.
North America is home to three vulture species:
1. Black Vulture
Scientific name: Coragyps atratus
The Black Vulture boasts an entirely black body, epitomizing the darkest hue among all vultures. Its back, wings, breast, belly, and tail display a uniform black color, although the underside of its wings presents silvery patches resembling fingers when in flight. The Black Vulture possesses brown eyes and grayish-white legs.
With a gray, featherless head and neck resembling wrinkled skin, the Black Vulture’s baldness serves a necessary purpose. It allows the bird to cleanse itself efficiently when remnants of carrion cling to its feathers after plunging into deceased animals.
While commonly referred to as the American Black Vulture, this name is merely used to distinguish it from the Eurasian Black Vulture (Aegypius monachus), and it is not its official designation.
Physical specifications:
– Length: 23 – 27 inches (58 – 69 cm)
– Weight: 76.8 ounces (2177 g)
– Wingspan: 54 – 60 inches (137 – 152 cm)
Black Vultures inhabit open lowland areas and middle elevations. They are frequently observed in forested landscapes, roosting in wooded regions near water sources. Other habitats include shrublands, grasslands, swamps, and pastures. They have even been sighted in human-populated towns scavenging in trash cans and garbage dumps.
Black Vultures are opportunistic feeders, consuming a wide range of food items, primarily carrion or decaying animals. While they are capable of locating dead animals themselves, they often rely on other scavenger birds to guide them to food sources. Their diet includes small to large-sized dead poultry, raccoons, coyotes, snakes, floating fish, as well as newborn calves, lambs, and tortoises. They are even known to scavenge in dumpsters and landfills.
In terms of vocalizations, Black Vultures emit few sounds, mainly producing deep cooing grunts.
As nest builders, Black Vultures are non-existent. Instead, they lay their eggs directly on the ground in caves, abandoned structures, thickets, and occasionally inside hollow trees or tree stumps. They frequently reuse successful nesting sites over several years.
Female Black Vultures lay one to three eggs, which are incubated by both parents for a period of twenty-eight to forty-one days. After hatching, the young are nourished through regurgitation, as the parents regurgitate food from their stomachs directly into the mouths of their offspring. The young vultures receive parental care for up to eight months.
Black Vultures form strong social bonds, leading to the establishment of communal roosts where food is shared among relatives. They display remarkable selectivity regarding non-relatives joining these communal roosts and will defend their territories against intruders.
Interesting fact: Black Vultures possess keen eyesight but lack a strong sense of smell, prompting them to trail others with superior olfactory abilities in order to locate food sources.
2. California Condor
Scientific name: Gymnogyps californianus
The California Condor holds the distinction of being the largest terrestrial bird in North America and is classified as a critically endangered species, with only approximately 500 individuals remaining as of 2020.
These majestic birds of prey possess expansive wings that resemble airplanes during flight, as they glide with minimal wing flapping. Their primary feathers extend like elongated “fingers” when airborne.
California Condors exhibit yellow skin on their heads and necks, which can transition from yellowish to red hues during courtship or when experiencing anger or distress. Their eyes are brownish-red, surrounded by red scleras.
During courtship or aggressive displays, California Condors inflate pinkish air sacs in their throat and near the breast, creating a noticeable puffing effect. Black feathers adorn the base of their necks, while their backs and wings exhibit a black coloration. Triangular white patches are visible on the underside of their wings during flight.
Juvenile California Condors resemble adults, although they differ in head coloration and the presence of gray mottling under their wings, replacing the white patches.
Physical specifications:
– Length: 46 – 52 inches (117 – 132 cm)
– Weight: 356.8 ounces (10,112 g)
– Wingspan: 72 – 108 inches (183 – 274 cm)
California Condors can be found in diverse habitats, including open or semi-open grasslands, scrublands, and woodlands suitable for foraging and nesting. They require elevations of up to 6,000 feet and prefer open and windy areas such as cliff edges or exposed tree branches, which provide high perches for launching into flight.
These birds primarily rely on thermals, upward currents of warm air, to gain altitude and maintain soaring in the air.
California Condors are scavengers, feasting on carrion from recently deceased or decaying animals. Their diet encompasses medium to large-sized carcasses, including sheep, deer, elk, horses, sea lions, and whales. They even consume smaller animal bones to supplement their calcium requirements.
When it comes to vocalizations, California Condors are generally silent, occasionally emitting grunts, hisses, or snorts.
Nests of California Condors are typically located in cliff caves, although these are not constructed nests. The female lays only one egg every other year, which contributes to their low population numbers. However, they are known to engage in “double clutching,” whereby they lay an additional egg to replace a lost one.
Researchers take advantage of this behavior by retrieving one egg to raise themselves, while leaving the second egg for the biological parents to rear. Incubation is carried out by both parents for approximately fifty-five days, and the young condors remain under parental care until their second year.
Interesting fact: California Condors possess an extended lifespan, capable of living up to sixty years. Despite being on the brink of extinction, successful conservation efforts have resulted in a population of around 500 individuals in the wild and in captivity.
3. Turkey Vulture
Scientific name: Cathartes aura
Turkey Vultures earn their name with their resemblance to turkeys, featuring large, bald, red heads and upper necks, complemented by brownish-black bodies. Although larger than actual turkeys, they share a similar “V” shape in their wings when in flight.
Gray coloring graces the underside of Turkey Vultures’ wings, creating a distinctive two-toned appearance. Their eyes are dark brown, and their bills exhibit a light hue.
Six subspecies of Turkey Vultures exist, with three of them inhabiting North America, often referred to as “Northern” Turkey Vultures. These subspecies display minor differences in tail and wing proportions, as well as variations in underwing feather colors.
Physical specifications:
– Length: 26 – 32 inches (66 – 81 cm)
– Weight: 51.2 ounces (1451 g)
– Wingspan: 68 – 72 inches (173 – 183 cm)
Turkey Vultures can be found in a wide range of habitats, with open and semi-open areas adjacent to woodlands being the most common. They require open landscapes such as grasslands, shrublands, deserts, wetlands for foraging, as well as forests with tall trees for nesting and roosting. They thrive in middle to high elevations, including hills and mountainous regions, to take advantage of increased altitude for flight.
These vultures may also venture into farmlands or pasturelands for foraging and roosting. In urban areas, they may occupy human-made structures only when preferred habitats are unavailable.
Turkey Vultures primarily feed on carrion, preferring recently deceased or decaying animals that haven’t undergone extensive decomposition. They scavenge roadkill, washed-up fish, and even target small or weak animals.
Regarding vocalizations, Turkey Vultures emit raspy hissing sounds, although they tend to be mostly silent.
Nests of Turkey Vultures are commonly found in sheltered areas like crevices in cliffs, old buildings, hollow trees, logs, and dense thickets. However, they do not construct nests per se. The female lays one to three eggs directly on the ground at the nesting site. Incubation is undertaken by both parents and lasts for approximately thirty-eight to forty-one days.
Interesting facts: Turkey Vultures possess a strong sense of smell, allowing them to detect odors of decaying or dead animals from significant distances. When threatened or agitated, they resort to vomiting as a distraction and may even feign death.