The Colombian woolly monkey (''Lagothrix lagothricha lugens'') is a

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

subspecies of the

common woolly monkey The common woolly monkey, brown woolly monkey, or Humboldt's woolly monkey (''Lagothrix lagothricha'') is a woolly monkey from Colombia, Ecuador, Peru, Bolivia, Brazil, and Venezuela. It lives in groups of two to 70 individuals, usually splitting ...

from

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

. It was initially thought to be a subspecies of the

(''L. lagothricha''), but was later reclassified as its own species. However, a 2014 phylogenetic study found it to in fact be a subspecies of ''L. lagothricha''; the results of this study have been followed by the

American Society of Mammalogists The American Society of Mammalogists (ASM) was founded in 1919. Its primary purpose is to encourage the study of mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence ...

and the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

. Among all

ateline The Atelinae are a subfamily of New World monkeys in the family Atelidae, and includes the various spider and woolly monkeys. The primary distinguishing feature of the atelines is their long prehensile tails, which can support their entire body w ...

primates, Colombian woolly monkeys exhibit the most

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

in body size. Males are about forty-five percent heavier than their female counterparts. However, the cause of this dimorphism remains an enigma as there are no apparent female choice in favor of larger males. In fact, mating amongst Colombian woolly monkeys is promiscuous in that all adult and subadult males in a group mate with each female in estrous, and male-male rivalries in the context of mating are very rare.

References

Colombian woolly monkey Subspecies Mammals of the Andes Mammals of Colombia Endemic fauna of Colombia Critically endangered animals Critically endangered biota of South America Colombian woolly monkey Taxa named by Daniel Giraud Elliot {{newworld-monkey-stub