The Northern Muriqui (Brachyteles hypoxanthus)

May 18, 2014 Features / Columnists, Interesting Creatures in Guyana

The Northern Muriqui (Brachyteles hypoxanthus) is an endangered muriqui (woolly spider monkey) species endemic to Brazil. It is unusual among primates in that it shows egaliterian social relationships. It is found in the Atlantic Forest region of the Brazilian states of Rio de Janeiro, Espírito Santo, Minas Gerais and Bahia.

Northern Muriqui

Muriquis are the largest species of New World monkeys. The northern muriqui can grow up to 4.3 ft tall. It feeds mainly on leaves and twigs, but will also eat fruit. It often hangs upside-down by its prehensile tail while eating.
Northern muriquis can be individually recognized by their natural markings and facial features, such as fur colour and patterning, ear shape, and face shape and pigmentation. Their sex can usually be determined within a week or so of birth, based on the shape and positioning of their genitalia.
The structure for Northern Muriqui is groups of male and females. Female Muriqui’s are more independent than males. Also females disperse from their natal groups at a mean age of six years. They are also known to engage in sex with multiple partners, a pattern that in other primates has been attributed to various functions such as confusing paternity, reducing male aggression, or ensuring fertilization.
A fact to note about the male Muriqui, is that there is almost no interaction between the male and infant. On the brief occasion that there is an interaction between the two, the infants would be the one to initiate. B. hypoxanthus is one of the world’s most critically endangered primates. The species is classified as critically endangered on the IUCN Red List of Threatened Species. It is threatened by hunting and (in common with most other primates of the region) destruction and fragmentation of its Atlantic Forest habitat.
Among the scattered populations of Northern Muriqui only one population, living in Caratinga is considered, as of now, viable for the next 100 years. The Northern Muriqui also suffers from very low genetic diversity and a lack of knowledge on their species, causing problems in conservation.
The estimated wild population of northern muriquis has increased from about 500 to 1,000 individuals in 2005, due to new discoveries and research in other forests.
The northern muriqui has been argued to be important to understanding human evolution, since it is one of the few primates that has tolerant, non-hierarchical relationships among and between males and females, a feature shared with hunter-gatherer humans, but which contrasts with the ranked relationships of most other primates.
Group aggression is also rare. The success of males fathering offspring links to the maternal investment they gain from their mothers and co-resident female kin.
(Source: Wikipedia – The Free Online Encyclopedia)