Lesser Yellow-headed Vulture
Encyclopedia
The Lesser Yellow-headed Vulture, Cathartes burrovianus, also known as the Savannah Vulture, is a species of bird
in the New World Vulture
family Cathartidae. It was considered to be the same species as the Greater Yellow-headed Vulture
until they were split in 1964. It is found in Mexico, Central America, and South America in seasonally wet or flooded lowland grassland
, swamp
s, and heavily degraded former forest. It is a large bird, with a wingspan of 150-165 centimeters (59–65 in). The body plumage
is black, and the head and neck, which are featherless, are pale orange with red or blue areas. It lacks a syrinx
, so therefore its vocalizations
are limited to grunts or low hisses.
The Lesser Yellow-headed Vulture feeds on carrion
and locates carcasses by sight and by smell, an ability which is rare in bird
s. It is dependent on larger vultures, such as the King Vulture
, to open the hides of larger animal carcasses as its bill is not strong enough to do this. Like other New World Vultures, the Lesser Yellow-headed Vulture utilizes thermal
s to stay aloft with minimal effort. It lays its eggs
on flat surfaces, such as the floors of cave
s, or in the hollows of stumps. It feeds its young by regurgitation
.
. It is sometimes recognized as having two subspecies. The first, Cathartes burrovianus urubitinga, described by Austrian ornithologist August von Pelzeln
in 1851, is the larger of the two and is found from Argentina north to Colombia, while the nominate subspecies, Cathartes burrovianus burrovianus, is smaller and found from northwestern South America through Central America to Mexico. The Lesser Yellow-headed Vulture's genus
, Cathartes, means "purifier" and is from the Latin
ized form of the Greek
kathartēs/καθαρτης. The common name
, vulture, is derived from the Latin
word vulturus, which means "tearer" and is a reference to its feeding habits.
The exact taxonomic placement of the Lesser Yellow-headed Vulture and the remaining six species of New World Vulture
s remains unclear. Although both are similar in appearance and have similar ecological roles
, the New World and Old World Vultures evolved from different ancestors in different parts of the world. Just how different the two are is currently under debate, with some earlier authorities suggesting that the New World vultures are more closely related to storks. More recent authorities maintain their overall position in the order Falconiformes
along with the Old World Vultures or place them in their own order, Cathartiformes. The South American Classification Committee has removed the New World Vultures from Ciconiiformes
and instead placed them in Incertae sedis
, but notes that a move to Falconiformes or Cathartiformes is possible. Like other New World vultures, the Lesser Yellow-headed Vulture has a diploid chromosome number of 80.
is black with a green sheen. The throat and the sides of the head are featherless. The head and neck are bare of feathers, and the skin is yellow, with a reddish forehead and nape and a gray-blue crown. The irises
of its eyes are red, its legs are white, and its beak is flesh-colored. The eye has a single incomplete row of eyelash
es on the upper lid and two rows on the lower lid.
The tail is rounded and relatively short for a vulture; the tip of the closed wing extends beyond the tail. Immature Lesser Yellow-headed Vultures have browner plumage, a dusky head, and a white nape.
The beak is thick, rounded, and hooked at the tip.
The front toes are long with small webs at their bases and are not adapted to grasping. The opening of the nostril is longitudinal, and the nostrils lack a septum
. Like all New World Vultures, the Lesser Yellow-headed Vulture lacks a syrinx
, and is therefore unable to make any sound other than a low hiss.
It differs in appearance from the similar Greater Yellow-headed Vulture
in several ways. It is smaller than the Greater Yellow-headed Vulture and has a shorter, thinner tail. The plumage is browner than the Greater Yellow-headed Vulture's dark, glossy black plumage. Its legs are lighter in color, and its head is more orange-tinged than the more yellow head of the Greater Yellow-headed Vulture. Its flight is also less steady than that of the Greater Yellow-headed Vulture. The Lesser Yellow-headed Vulture also prefers to live in savannas, as opposed to the preferred forest habitat of the Greater Yellow-headed Vulture, and is less heavily built.
Besides the Greater Yellow-headed Vulture, it is similar to the Turkey Vulture
.
It is found in Argentina, Belize
, Bolivia
, Brazil, Chile
, Colombia
, Costa Rica
, Ecuador
, El Salvador
, French Guiana
, Guatemala
, Guyana
, Honduras
, Mexico, Nicaragua
, Panama
, Paraguay
, Peru
, Suriname
, Uruguay
, and Venezuela
.
Its natural habitat
s are subtropical or tropical seasonally wet or flooded lowland grassland
, swamp
s, mangrove
s, and heavily degraded former forest. It may wander over dry fields and clearings. It is not generally found in high-altitude regions.
s, has the unusual habit of urohidrosis
, in which it urinates or defecates on its legs to cool them by evaporation.
and subsists almost entirely on carrion
. It will eat roadkill or the carcass of any animal, but is also known to hunt for food, especially small aquatic animals in marshes. It prefers fresh meat, but often cannot make the first cut into the carcass of a larger animal because its beak is not strong enough to tear into the tough hide. The Lesser Yellow-headed Vulture will no longer feed on a piece of carrion once the meat is in a state of extreme decay, as it becomes contaminated with microbial toxins
. Like other vultures, it plays an important role in its ecosystem
by disposing of carrion which would otherwise be a breeding ground for disease.
The Lesser Yellow-headed Vulture forages using its keen eyesight to locate carrion on the ground, but also uses its sense of smell, an ability which is uncommon in the avian world. It locates carrion by detecting the scent of ethyl mercaptan
, a gas produced by the beginnings of decay in dead animals.
The olfactory lobe
of its brain
responsible for processing smells is particularly large compared to other animals. This characteristic of New World Vultures has been used by humans: ethyl mercaptan is injected into pipelines, and engineers looking for leaks then follow the foraging vultures.
King Vulture
s, which lack the ability to smell carrion, follow the Lesser Yellow-headed Vultures to carcasses, where the King Vulture tears open the skin of the dead animal. This allows the smaller Lesser Yellow-headed Vulture access to food, as it does not have a bill strong enough to tear the hide of larger animals. This is an example of mutual dependence between species. It is generally displaced from carcasses by both Turkey Vulture
s and King Vulture
s, due to their larger size.
on the ground, cliff ledges, the floors of caves, or in the hollow of a tree. Eggs are cream colored and heavily blotched with brown and gray spots, particularly around the larger end. Two eggs are generally laid. The chicks are altricial
—they are blind, naked and relatively immobile upon hatching. The chicks do not grow their down feather
s until later. The parents feed their young by regurgitating
pre-digested food into their beak
, where the chicks then drink it. Young fledge
after two to three months.
of 7,800,000 square kilometers and a population of between 100,000 and 1,000,000 individuals. Its population trend appears to be stable.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
in the New World Vulture
New World vulture
The New World Vulture or Condor family Cathartidae contains seven species in fivegenera, all but one of which are monotypic. It includes five vultures and two condors found in warm and temperate areas of the Americas....
family Cathartidae. It was considered to be the same species as the Greater Yellow-headed Vulture
Greater Yellow-headed Vulture
The Greater Yellow-headed Vulture, Cathartes melambrotus, also known as the Forest Vulture, is a species of bird in the New World Vulture family Cathartidae. It was considered to be the same species as the Lesser Yellow-headed Vulture until they were split in 1964. It is found in South America in...
until they were split in 1964. It is found in Mexico, Central America, and South America in seasonally wet or flooded lowland grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
, swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
s, and heavily degraded former forest. It is a large bird, with a wingspan of 150-165 centimeters (59–65 in). The body plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
is black, and the head and neck, which are featherless, are pale orange with red or blue areas. It lacks a syrinx
Syrinx (biology)
Syrinx is the name for the vocal organ of birds. Located at the base of a bird's trachea, it produces sounds without the vocal cords of mammals. The sound is produced by vibrations of some or all of the membrana tympaniformis and the pessulus caused by air flowing through the syrinx...
, so therefore its vocalizations
Bird song
Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology and birding, songs are distinguished by function from calls.-Definition:The distinction between songs and calls is based upon...
are limited to grunts or low hisses.
The Lesser Yellow-headed Vulture feeds on carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
and locates carcasses by sight and by smell, an ability which is rare in bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s. It is dependent on larger vultures, such as the King Vulture
King Vulture
The King Vulture is a large bird found in Central and South America. It is a member of the New World vulture family Cathartidae. This vulture lives predominantly in tropical lowland forests stretching from southern Mexico to northern Argentina, though some believe that William Bartram's Painted...
, to open the hides of larger animal carcasses as its bill is not strong enough to do this. Like other New World Vultures, the Lesser Yellow-headed Vulture utilizes thermal
Thermal
A thermal column is a column of rising air in the lower altitudes of the Earth's atmosphere. Thermals are created by the uneven heating of the Earth's surface from solar radiation, and are an example of convection. The sun warms the ground, which in turn warms the air directly above it...
s to stay aloft with minimal effort. It lays its eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
on flat surfaces, such as the floors of cave
Cave
A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...
s, or in the hollows of stumps. It feeds its young by regurgitation
Regurgitation (digestion)
Regurgitation is the expulsion of material from the mouth, pharynx, or esophagus, usually characterized by the presence of undigested food or blood.Regurgitation is used by a number of species to feed their young...
.
Taxonomy
The Lesser Yellow-headed Vulture was first described in 1845 by John CassinJohn Cassin
John Cassin was an American ornithologist.He is considered to be one of the giants of American ornithology, and was America's first taxonomist, describing 198 birds not previously mentioned by Alexander Wilson and John James Audubon...
. It is sometimes recognized as having two subspecies. The first, Cathartes burrovianus urubitinga, described by Austrian ornithologist August von Pelzeln
August von Pelzeln
August von Pelzeln was an Austrian ornithologist.August Edler Pelzeln was in charge of the mammal and bird collections at the Imperial Natural History Museum in Vienna...
in 1851, is the larger of the two and is found from Argentina north to Colombia, while the nominate subspecies, Cathartes burrovianus burrovianus, is smaller and found from northwestern South America through Central America to Mexico. The Lesser Yellow-headed Vulture's genus
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...
, Cathartes, means "purifier" and is from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
ized form of the Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
kathartēs/καθαρτης. The common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
, vulture, is derived from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
word vulturus, which means "tearer" and is a reference to its feeding habits.
The exact taxonomic placement of the Lesser Yellow-headed Vulture and the remaining six species of New World Vulture
New World vulture
The New World Vulture or Condor family Cathartidae contains seven species in fivegenera, all but one of which are monotypic. It includes five vultures and two condors found in warm and temperate areas of the Americas....
s remains unclear. Although both are similar in appearance and have similar ecological roles
Ecological niche
In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...
, the New World and Old World Vultures evolved from different ancestors in different parts of the world. Just how different the two are is currently under debate, with some earlier authorities suggesting that the New World vultures are more closely related to storks. More recent authorities maintain their overall position in the order Falconiformes
Falconiformes
The order Falconiformes is a group of about 290 species of birds that comprises the diurnal birds of prey. Raptor classification is difficult and the order is treated in several ways.- Classification problems :...
along with the Old World Vultures or place them in their own order, Cathartiformes. The South American Classification Committee has removed the New World Vultures from Ciconiiformes
Ciconiiformes
Traditionally, the order Ciconiiformes has included a variety of large, long-legged wading birds with large bills: storks, herons, egrets, ibises, spoonbills, and several others. Ciconiiformes are known from the Late Eocene...
and instead placed them in Incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
, but notes that a move to Falconiformes or Cathartiformes is possible. Like other New World vultures, the Lesser Yellow-headed Vulture has a diploid chromosome number of 80.
Description
The Lesser Yellow-headed Vulture is 53 – in length, with a wingspan of 150 – and a tail length of 19 –. Its weight ranges from 0.95 to 1.55 kg (2.1 to 3.4 lb). Its plumagePlumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
is black with a green sheen. The throat and the sides of the head are featherless. The head and neck are bare of feathers, and the skin is yellow, with a reddish forehead and nape and a gray-blue crown. The irises
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
of its eyes are red, its legs are white, and its beak is flesh-colored. The eye has a single incomplete row of eyelash
Eyelash
An eyelash or simply lash is one of the hairs that grow at the edge of the eyelid. Eyelashes protect the eye from debris and perform some of the same function as whiskers do on a cat or a mouse in the sense that they are sensitive to being touched, thus providing a warning that an object is near...
es on the upper lid and two rows on the lower lid.
The tail is rounded and relatively short for a vulture; the tip of the closed wing extends beyond the tail. Immature Lesser Yellow-headed Vultures have browner plumage, a dusky head, and a white nape.
The beak is thick, rounded, and hooked at the tip.
The front toes are long with small webs at their bases and are not adapted to grasping. The opening of the nostril is longitudinal, and the nostrils lack a septum
Septum
In anatomy, a septum is a wall, dividing a cavity or structure into smaller ones.-In human anatomy:...
. Like all New World Vultures, the Lesser Yellow-headed Vulture lacks a syrinx
Syrinx (biology)
Syrinx is the name for the vocal organ of birds. Located at the base of a bird's trachea, it produces sounds without the vocal cords of mammals. The sound is produced by vibrations of some or all of the membrana tympaniformis and the pessulus caused by air flowing through the syrinx...
, and is therefore unable to make any sound other than a low hiss.
It differs in appearance from the similar Greater Yellow-headed Vulture
Greater Yellow-headed Vulture
The Greater Yellow-headed Vulture, Cathartes melambrotus, also known as the Forest Vulture, is a species of bird in the New World Vulture family Cathartidae. It was considered to be the same species as the Lesser Yellow-headed Vulture until they were split in 1964. It is found in South America in...
in several ways. It is smaller than the Greater Yellow-headed Vulture and has a shorter, thinner tail. The plumage is browner than the Greater Yellow-headed Vulture's dark, glossy black plumage. Its legs are lighter in color, and its head is more orange-tinged than the more yellow head of the Greater Yellow-headed Vulture. Its flight is also less steady than that of the Greater Yellow-headed Vulture. The Lesser Yellow-headed Vulture also prefers to live in savannas, as opposed to the preferred forest habitat of the Greater Yellow-headed Vulture, and is less heavily built.
Besides the Greater Yellow-headed Vulture, it is similar to the Turkey Vulture
Turkey Vulture
The Turkey Vulture is a bird found throughout most of the Americas. It is also known in some North American regions as the Turkey Buzzard , and in some areas of the Caribbean as the John Crow or Carrion Crow...
.
Distribution and habitat
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...
, Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
, Brazil, Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, El Salvador
El Salvador
El Salvador or simply Salvador is the smallest and the most densely populated country in Central America. The country's capital city and largest city is San Salvador; Santa Ana and San Miguel are also important cultural and commercial centers in the country and in all of Central America...
, French Guiana
French Guiana
French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...
, Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
, Guyana
Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...
, Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
, Mexico, Nicaragua
Nicaragua
Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...
, Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
, Paraguay
Paraguay
Paraguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, Suriname
Suriname
Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...
, Uruguay
Uruguay
Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...
, and Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
.
Its natural habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s are subtropical or tropical seasonally wet or flooded lowland grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
, swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
s, mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s, and heavily degraded former forest. It may wander over dry fields and clearings. It is not generally found in high-altitude regions.
Ecology and behavior
The Lesser Yellow-headed Vulture flies solitarily, with wings held in a dihedral position. It glides at a low altitude over wetlands while locating food, and perches on fence posts or on other low perches. When flying, it travels alone and is rarely found in groups. The flight of the lesser Yellow-Headed is an example of static soaring flight, which uses thermals to maintain altitude without the need to flap its wings. This vulture rarely soars high in the air, preferring low altitudes. This bird is believed to be somewhat migratory in response to the changes in water level where it lives. The Lesser Yellow-headed Vulture, like other New World VultureNew World vulture
The New World Vulture or Condor family Cathartidae contains seven species in fivegenera, all but one of which are monotypic. It includes five vultures and two condors found in warm and temperate areas of the Americas....
s, has the unusual habit of urohidrosis
Urohidrosis
Urohidrosis is the habit in some birds of defecating onto the scaly portions of the legs as a cooling mechanism, using evaporative cooling of the fluids. Several species of storks and New World vultures exhibit this behaviour. Birds' droppings consist of faeces and urine, which are excreted...
, in which it urinates or defecates on its legs to cool them by evaporation.
Diet
The Lesser Yellow-headed Vulture is a scavengerScavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...
and subsists almost entirely on carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
. It will eat roadkill or the carcass of any animal, but is also known to hunt for food, especially small aquatic animals in marshes. It prefers fresh meat, but often cannot make the first cut into the carcass of a larger animal because its beak is not strong enough to tear into the tough hide. The Lesser Yellow-headed Vulture will no longer feed on a piece of carrion once the meat is in a state of extreme decay, as it becomes contaminated with microbial toxins
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
. Like other vultures, it plays an important role in its ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
by disposing of carrion which would otherwise be a breeding ground for disease.
The Lesser Yellow-headed Vulture forages using its keen eyesight to locate carrion on the ground, but also uses its sense of smell, an ability which is uncommon in the avian world. It locates carrion by detecting the scent of ethyl mercaptan
Ethanethiol
Ethanethiol is an organic compound with the formula CH3CH2SH. It consists of an ethyl group, CH3CH2, attached to a thiol group, SH. Its structure parallels that of ethanol, but with S instead of O. The presence of S leads to many different properties, most notably the infamous odour of EtSH...
, a gas produced by the beginnings of decay in dead animals.
The olfactory lobe
Olfaction
Olfaction is the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertebrates, and, by analogy, sensory cells of the antennae of invertebrates...
of its brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
responsible for processing smells is particularly large compared to other animals. This characteristic of New World Vultures has been used by humans: ethyl mercaptan is injected into pipelines, and engineers looking for leaks then follow the foraging vultures.
King Vulture
King Vulture
The King Vulture is a large bird found in Central and South America. It is a member of the New World vulture family Cathartidae. This vulture lives predominantly in tropical lowland forests stretching from southern Mexico to northern Argentina, though some believe that William Bartram's Painted...
s, which lack the ability to smell carrion, follow the Lesser Yellow-headed Vultures to carcasses, where the King Vulture tears open the skin of the dead animal. This allows the smaller Lesser Yellow-headed Vulture access to food, as it does not have a bill strong enough to tear the hide of larger animals. This is an example of mutual dependence between species. It is generally displaced from carcasses by both Turkey Vulture
Turkey Vulture
The Turkey Vulture is a bird found throughout most of the Americas. It is also known in some North American regions as the Turkey Buzzard , and in some areas of the Caribbean as the John Crow or Carrion Crow...
s and King Vulture
King Vulture
The King Vulture is a large bird found in Central and South America. It is a member of the New World vulture family Cathartidae. This vulture lives predominantly in tropical lowland forests stretching from southern Mexico to northern Argentina, though some believe that William Bartram's Painted...
s, due to their larger size.
Reproduction
Lesser Yellow-headed Vultures do not build nests, but rather lay eggsBird egg
Bird eggs are laid by females and incubated for a time that varies according to the species; a single young hatches from each egg. Average clutch sizes range from one to about 17...
on the ground, cliff ledges, the floors of caves, or in the hollow of a tree. Eggs are cream colored and heavily blotched with brown and gray spots, particularly around the larger end. Two eggs are generally laid. The chicks are altricial
Altricial
Altricial, meaning "requiring nourishment", refers to a pattern of growth and development in organisms which are incapable of moving around on their own soon after hatching or being born...
—they are blind, naked and relatively immobile upon hatching. The chicks do not grow their down feather
Down feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...
s until later. The parents feed their young by regurgitating
Regurgitation (digestion)
Regurgitation is the expulsion of material from the mouth, pharynx, or esophagus, usually characterized by the presence of undigested food or blood.Regurgitation is used by a number of species to feed their young...
pre-digested food into their beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
, where the chicks then drink it. Young fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
after two to three months.
Conservation
The Lesser Yellow-headed Vulture is a bird of Least Concern according to the IUCN, with an estimated global rangeRange (biology)
In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
of 7,800,000 square kilometers and a population of between 100,000 and 1,000,000 individuals. Its population trend appears to be stable.
External links
- Lesser Yellow-headed Vulture photos and information
- Lesser Yellow-headed Vulture photo gallery VIREO
- Photo-Medium Res; Article home.scarlet.be
- Photo-High Res; Article chandra.as.utexas.edu
