The Yucatán black howler, or Guatemalan black howler, (''Alouatta pigra'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

howler monkey Howler monkeys (genus ''Alouatta'', monotypic in subfamily Alouattinae) are the most widespread primate genus in the Neotropical realm, Neotropics and are among the largest of the New World monkey, platyrrhines along with the muriquis (''Brachyte ...

, a type of

New World monkey New World monkeys are the five families of primates that are found in the tropical regions of Mexico, Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Ceboi ...

, from

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

. It is found in

Belize Belize is a country on the north-eastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a maritime boundary with Honduras to the southeast. P ...

Guatemala Guatemala, officially the Republic of Guatemala, is a country in Central America. It is bordered to the north and west by Mexico, to the northeast by Belize, to the east by Honduras, and to the southeast by El Salvador. It is hydrologically b ...

and

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, in and near the

Yucatán Peninsula The Yucatán Peninsula ( , ; ) is a large peninsula in southeast Mexico and adjacent portions of Belize and Guatemala. The peninsula extends towards the northeast, separating the Gulf of Mexico to the north and west of the peninsula from the C ...

. It lives in

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

, semideciduous and lowland rain forests. It is also known as the baboon in Belize, although it is not closely related to the

baboon Baboons are primates comprising the biology, genus ''Papio'', one of the 23 genera of Old World monkeys, in the family Cercopithecidae. There are six species of baboon: the hamadryas baboon, the Guinea baboon, the olive baboon, the yellow ba ...

s in

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Description

The Yucatán black howler is the largest of the howler monkey species and one of the largest of the

s. Yucatán black howler males are larger than those of any other Central American monkey species. On average, males weigh and females weigh . The body is between in length, excluding the tail. The tail is between long. Adults of both sexes have long, black hair and a

prehensile Prehensility is the quality of an appendage or organ that has adapted for grasping or holding. The word is derived from the Latin term ''prehendere'', meaning "to grasp". The ability to grasp is likely derived from a number of different origin ...

tail, while infants have brown fur. Males over four months old have white scrotums. The Yucatán black howler shares several adaptations with other species of howler monkey that allow it to pursue a folivorous diet (mostly leaves). Its molars have high shearing crests, to help it eat the leaves. The male of the species has an enlarged

hyoid The hyoid-bone (lingual-bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid-cartilage. At rest, it lies between the base of the mandible and the third cervical verte ...

bone near the vocal cords. This hyoid bone amplifies the male howler's calls, allowing it to locate other males without expending much energy, which is important, since leaves are a low-energy food. Howling occurs primarily at dawn and at dusk. The Yucatán black howler is diurnal and

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The hab ...

. It lives in groups of generally one or two adult males, with a ratio of about 1.3 females for every male. Groups generally have between two and 10 members, including juveniles, but groups as large as 16 members have been studied. The home range is between 3 and 25

hectare The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), that is, square metres (), and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. ...

s. Population density can exceed 250 monkeys per square kilometer in the Community Baboon Sanctuary in

. The Yucatán black howler's diet includes mostly leaves and

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

. Flowers also make up a small part of the diet. The breadnut tree can provide as much as 86% of the monkey's diet during some seasons. As with other howler monkey species, the majority of the Yucatán black howler's day is spent resting. Eating makes up about a quarter of the day, moving about 10% of the day, and the remainder of the day is spent in socializing and other activities. Females reach sexual maturity at four, and males reach sexual maturity between six and eight years old. Males leave their natal group upon reaching sexual maturity, but females generally remain with their natal group. They can live up to 20 years. Yucatán black howler (Alouatta pigra) feeding Cayo.jpg, feeding, Belize Yucatán black howler (Alouatta pigra) Peten.jpg, feeding, Guatemala Yucatán black howler (Alouatta pigra) with baby Peten.jpg, with baby, Guatemala

Conservation status

The Yucatán black howler belongs to the New World monkey family

Atelidae The Atelidae are one of the five families of New World monkeys now recognised. It was formerly included in the family Cebidae. Atelids are generally larger monkeys; the family includes the howler, spider, woolly, and woolly spider monkeys (t ...

, which contains

spider monkey Spider monkeys are New World monkeys belonging to the genus ''Ateles'', part of the subfamily Atelinae, family Atelidae. Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil. The g ...

woolly monkey The woolly monkeys are the genus ''Lagothrix'' of New World monkeys, usually placed in the family Atelidae. Both species in this genus originate from the rainforests of South America. They have prehensile tails and live in relatively large soci ...

s and

muriqui The muriquis, also known as woolly spider monkeys, are the monkeys of the genus ''Brachyteles''. They are closely related to both the spider monkeys and the woolly monkeys. Species The two species are: They are the two largest species ...

s. It is a member of the howler monkey genus ''

Alouatta Howler monkeys (genus ''Alouatta'', monotypic in subfamily Alouattinae) are the most widespread primate genus in the Neotropics and are among the largest of the platyrrhines along with the muriquis (''Brachyteles''), the spider monkeys (''Atele ...

''. No subspecies are recognized. The species is considered to be endangered by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

because the species population is expected to decline by up to 60% over the next 30 years. Threats to the species include

habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

, hunting, and capture as pets. In Belize, it is illegal to hunt this species.

Sympatry

The Yucatán black howler is

sympatric In biology, two closely related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter each other. An initially interbreeding population that splits into two or more distinct spe ...

with the

mantled howler The mantled howler (''Alouatta palliata'') is a species of howler monkey, a type of New World monkey, from Central America, Central and South America. It is one of the monkey species most often seen and heard in the wild in Central America. It ta ...

along the edges of its range in Mexico and Guatemala near the Yucatan Peninsula. A theory for how this sympatry occurred and why the Yucatán black howler has such a restricted range is the ancestors of the Yucatán black howler and the

Central American squirrel monkey The Central American squirrel monkey (''Saimiri oerstedii''), also known as the red-backed squirrel monkey, is a squirrel monkey species from the Pacific coast of Costa Rica and Panama. It is restricted to the northwestern tip of Panama near the ...

migrated to

from

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

during the late

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Isthmus An isthmus (; : isthmuses or isthmi) is a narrow piece of land connecting two larger areas across an expanse of water by which they are otherwise separated. A tombolo is an isthmus that consists of a spit or bar, and a strait is the sea count ...

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

then closed for a period due to

rising sea levels The sea level has been rising from the end of the last ice age, which was around 20,000 years ago. Between 1901 and 2018, the average sea level rose by , with an increase of per year since the 1970s. This was faster than the sea level had e ...

, and later opened up to another wave of migration about two million years ago. These later migrants, ancestors to modern populations of

white-headed capuchin White-faced capuchin, or white headed capuchin, can refer to either of two species of gracile capuchin monkey: * ''Cebus imitator'', the Panamanian white-faced capuchin, also known as the Panamanian white-headed capuchin or Central American w ...

s, mantled howlers and

Geoffroy's spider monkey Geoffroy's spider monkey (''Ateles geoffroyi''), also known as the black-handed spider monkey or the Central American spider monkey, is a species of spider monkey, a type of New World monkey, from Central America, parts of Mexico and possibly a ...

s, out-competed the earlier migrants, leading to the restricted range of the Yucatán black howler (and the Central American squirrel monkey).

References

External links

* ARKive &ndash
images and movies of the Yucatán black howler ''(Alouatta pigra)''

Sound recordings of Yucatán black howlers at BioAcoustica
{{Taxonbar, from=Q849419 Howler monkeys Primates of Central America Mammals of Mexico Fauna of Southern Mexico Fauna of the Yucatán Peninsula Endangered biota of Mexico Endangered fauna of North America Mammals described in 1933 Taxa named by Barbara Lawrence (zoologist)

Description

Conservation status

Sympatry

See Also

References

External links