Red-handed Howler
Encyclopedia
The red-handed howler is a vulnerable
species of howler monkey
, a type of New World monkey
. It is endemic to Brazil
, where found in the south-eastern Amazon
and disjunctly
in Atlantic Forest between Rio Grande do Norte
and Sergipe
.
Considerable taxonomic confusion has surrounded this species. Until 2001, most authorities included the Amazon black howler
as a subspecies
(or simply a taxonomically insignificant variation) of the Red-handed Howler, though its distinction had already been pointed out much earlier. The Red-handed Howler remained variable in ecology
, colour and pattern of the fur
, shape of the cranium, and shape of the hyoid bone
(of great importance in the voice of the howler monkeys; a likely isolating mechanism
between the species), but a geographical pattern was not clear, resulting in it being treated as a monotypic
species. In 2006, a major review of the Brazilian members of the genus Alouatta was able to match some of the variations to geography (though further study was recommended), resulting in the recognition of the Spix's red-handed howler
and Maranhão red-handed howler
as species separate from the red-handed howler. Even with these as separate species, the colour and pattern of the fur of the red-handed howler remains variable. Most adults are black with reddish-brown hands, feet and distal part of the tail, but some are entirely black (resembling the Amazon black howler), reddish (resembling the red howlers) or somewhere in between.
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
species of howler monkey
Howler monkey
Howler monkeys are among the largest of the New World monkeys. Fifteen species are currently recognised. Previously classified in the family Cebidae, they are now placed in the family Atelidae. These monkeys are native to South and Central American forests...
, a type of New World monkey
New World monkey
New World monkeys are the five families of primates that are found in Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Platyrrhini parvorder and the Ceboidea superfamily, which are essentially synonymous since...
. It is endemic to Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, where found in the south-eastern Amazon
Amazon Rainforest
The Amazon Rainforest , also known in English as Amazonia or the Amazon Jungle, is a moist broadleaf forest that covers most of the Amazon Basin of South America...
and disjunctly
Disjunct distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but widely separated from each other geographically...
in Atlantic Forest between Rio Grande do Norte
Rio Grande do Norte
Rio Grande do Norte is one of the states of Brazil, located in the northeastern region of the country, occupying the northeasternmost tip of the South American continent. Because of its geographic position, Rio Grande do Norte has a strategic importance. The capital and largest city is Natal...
and Sergipe
Sergipe
Sergipe , is the smallest state of the Brazilian Federation, located on the northeastern Atlantic coast of the country. It borders on two other states, Bahia to the south and west and Alagoas to the north, and to the east is the Atlantic Ocean...
.
Considerable taxonomic confusion has surrounded this species. Until 2001, most authorities included the Amazon black howler
Amazon Black Howler
The Amazon black howler is a species of howler monkey, a type of New World monkey, endemic to the south-central Amazon in Brazil. Until 2001, most authorities included it as a subspecies of the red-handed howler, though its distinction had already been pointed out much earlier...
as a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
(or simply a taxonomically insignificant variation) of the Red-handed Howler, though its distinction had already been pointed out much earlier. The Red-handed Howler remained variable in ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
, colour and pattern of the fur
Fur
Fur is a synonym for hair, used more in reference to non-human animals, usually mammals; particularly those with extensives body hair coverage. The term is sometimes used to refer to the body hair of an animal as a complete coat, also known as the "pelage". Fur is also used to refer to animal...
, shape of the cranium, and shape of the hyoid bone
Hyoid bone
The hyoid 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 at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...
(of great importance in the voice of the howler monkeys; a likely isolating mechanism
Reproductive isolation
The mechanisms of reproductive isolation or hybridization barriers are a collection of mechanisms, behaviors and physiological processes that prevent the members of two different species that cross or mate from producing offspring, or which ensure that any offspring that may be produced is not...
between the species), but a geographical pattern was not clear, resulting in it being treated as a monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
species. In 2006, a major review of the Brazilian members of the genus Alouatta was able to match some of the variations to geography (though further study was recommended), resulting in the recognition of the Spix's red-handed howler
Spix's Red-handed Howler
Spix's red-handed howler is a vulnerable species of howler monkey native to the south-eastern Amazon in Brazil. Major threats include deforestation and hunting...
and Maranhão red-handed howler
Maranhão Red-handed Howler
The Maranhão red-handed howler is an endangered species of howler monkey that is endemic to forests in the northeast Brazilian states of Ceará, Maranhão and Piauí. It was previously thought to be a subspecies of the Red-handed Howler, but unlike that species the Maranhão Red-handed Howler is...
as species separate from the red-handed howler. Even with these as separate species, the colour and pattern of the fur of the red-handed howler remains variable. Most adults are black with reddish-brown hands, feet and distal part of the tail, but some are entirely black (resembling the Amazon black howler), reddish (resembling the red howlers) or somewhere in between.