The northern muriqui (''Brachyteles hypoxanthus)'' is one of two
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of muriqui. They are also known as woolly spider monkey because they exhibit the woollen
pelt of
woolly monkeys
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 ...
and the long
prehensile tail
A prehensile tail is the tail of an animal that has adapted to grasp or hold objects. Fully prehensile tails can be used to hold and manipulate objects, and in particular to aid arboreal creatures in finding and eating food in the trees. If the ta ...
of
spider monkeys
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 ...
. Muriquis are the largest extant New World monkeys. They can reach long and weight up to .
The northern muriqui is a critically endangered species that is unusual among primates in that they display
egaltarian tendencies in their social relationships. This species is
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to the
Atlantic Forest
The Atlantic Forest ( pt, Mata Atlântica) is a South American forest that extends along the Atlantic coast of Brazil from Rio Grande do Norte state in the northeast to Rio Grande do Sul state in the south and inland as far as Paraguay and th ...
region of Brazilian states of
Rio de Janeiro
Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...
,
Espírito Santo,
Minas Gerais
Minas Gerais () is a state in Southeastern Brazil. It ranks as the second most populous, the third by gross domestic product (GDP), and the fourth largest by area in the country. The state's capital and largest city, Belo Horizonte (literally ...
and
Bahia
Bahia ( , , ; meaning "bay") is one of the 26 Federative units of Brazil, states of Brazil, located in the Northeast Region, Brazil, Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo (sta ...
. Their diets, travel patterns and reproductive cycles are
seasonally determined. The size of each group can fluctuate as females will move between groups of monkeys.
Morphology and identification
![Northern Muriqui 9](https://upload.wikimedia.org/wikipedia/commons/2/2f/Northern_Muriqui_9.jpg)
Northern muriquis exhibit features that allow them to utilize all of their limbs and tail for travel and obtaining food items. As they spend much of their life in the canopy of forests, they use
brachiation
Brachiation (from "brachium", Latin for "arm"), or arm swinging, is a form of arboreal locomotion in which primates swing from tree limb to tree limb using only their arms. During brachiation, the body is alternately supported under each forelimb ...
as a form of locomotion utilizing all four limbs and their tail.
Evolutionary features that further aid these large
atelids are elongated hook-like fingers, and shoulder that allows for a wide range of movement.
As these monkeys are primarily suited for life in trees, they still venture down to the ground to drink from water sources, consume soil or to obtain ripe fruit that has fallen.
Northern muriquis can be individually recognized by their natural markings and facial features, such as fur color and patterning, ear shape, and face shape and pigmentation. In contrast to the
southern muriqui
The southern muriqui (''Brachyteles arachnoides'') is a muriqui (woolly spider monkey) species endemic to Brazil.
Taxonomy
Taxonomy of muriquis is controversial because some scientists believe that they are a monotypic genus while others favo ...
, northern muriqui exhibit a lack of
sexual dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
, southern muriqui exhibit dimorphism in their canines, but northern muriqui have kept
vestigial
Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on co ...
thumbs.
Ecology
Diet
Northern muriqui are
frugivorous
A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and ...
and
folivorous, but they also rely on flowers, bark, twigs, stems and soil to supplement additional nutritional needs.
The amount of what each group eats depends on seasonality, wherein they will consume foods higher in calories, which results in higher fruit consumption during the wet season, and increased leaf consumption in the dry season. This affect how groups of ''B. hypoxanthus'' travel as they forage for food, as bigger family groups need to travel further to attain adequate food sources. The muriqui also utilize vertical niches when foraging, as they can access all levels of forest, from the floor to the canopy. Muriqui group home ranges overlap, so unrelated groups of muriqui will avoid each other by traveling to or foraging for food by using these niche levels.
Social structure
Northern muriqui live in egalitarian,
fission-fusion societies,
where the males are
philopatric
Philopatry is the tendency of an organism to stay in or habitually return to a particular area. The causes of philopatry are numerous, but natal philopatry, where animals return to their birthplace to breed, may be the most common. The term derives ...
, and females will leave the natal group to join other muriqui groups at an average age of 6 years old before they reach puberty. Male muriqui have been documented to form social
cliques within their natal groups, with groups that are differentiated between older males and younger males.
Males display tendencies to form cooperative associations between cliques, and therefore leads to diminished
intragroup conflicts compared to other species of primate. These tendencies make themselves apparent during mating season as there is little to no aggression displayed between males vying for mating opportunities, or when dealing with other natal groups of muriqui when traveling or defending their own
homerange.
Different muriqui groups will interact with each other as group home ranges overlap.
During these interactions, females can enter new groups by vocalizing and interacting with new group members by hugging or touching them. Female muriquis are more independent than males; they leave their natal groups at an age of about six years.
[Strier, KB, SL Mendes, and K. "Web of Knowledge ]5.6 .22 caliber, or 5.6 mm caliber, refers to a common firearms caliber, bore diameter of 0.22 inch (5.6 mm).
Cartridge (firearms), Cartridges in this caliber include the very widely used .22 Long Rifle and .223 Remington / 5.56×45mm NATO.
...
" Genetic Diversity and Population History of a Critically Endangered Primate, the Northern Muriqui 17.2 (2011): 53-69. Web.Male muriquis have almost no interaction with infants. When there is an interaction between the two, the infant would be the one to initiate it.
[Oliveria Guimaraes, Vanessa. "Adult Male-infant Interactions in Wild Muriquis (Brachyteles Arachnoides Hypoxanthus)." N.p., Oct. 2001. Web. 26 Oct. 2012.] Muriqui social groups are dominated by females, and males will continue to associate closely with their mothers into adulthood. It is through their mothers that adult males gain access to more females.
Mating and reproduction
The Northern muriqui's reproductive cycle is based on the seasonality of their environment. Infants are generally born during the dry season so that when there is a high amount of fruit production during the wet season, they can access calorie dense foods as they are
weaned
Weaning is the process of gradually introducing an infant human or another mammal to what will be its adult diet while withdrawing the supply of its mother's milk.
The process takes place only in mammals, as only mammals produce milk. The infan ...
off of their mothers milk. Females will on average be ready to mate at the age of nine, wherein they can copulate with several partners in order to conceive, however,some males can be shown preferential treatment by females.
Evidence points to having multiple partners in order to confuse paternity, limit male aggression, or improving odds of fertilization.
[Possami, Carla.]
Socio-Sexual Behavior of Female Northern Muriquis
" Socio-Sexual Behavior of Female Northern Muriquis 69.7 (2007). Web. The gestation period for northern muriquis is a little over 7 months. The visual determination of sex can be seen within a week or so of birth, based on the shape and positioning of their genitalia.
[ Strier, Karen B, Jean P. Boubli, Carla B Possamai, and Se ́ rgio L. Mendes4.]
Population Demography of Northern Muriquis (Brachyteles Hypoxanthus) at the Estac ̧ a ̃ O Biolo ́ Gica De Caratinga/Reserva Particular Do Patrimoˆ Nio Natural-Felı`ciano
Miguel Abdala, Minas Gerais, Brazil."AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY (2006): 1-3. There is no definitive research on the average life span of the northern muriqui, there are documented individuals reaching past the age of 30 years of age.
Conservation and status
''B. hypoxanthus'' is one of the world's most
critically endangered primates, according to 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.
[Brito, Daniel, and Carlos Eduardo V. Grelle. Estimating Minimum Area of Suitable Habitat and Viable Population Size for the Northern Muriqui. Pdfcast.org. Springer, n.d. Web. 26 Oct. 2012.http://pdfcast.org/pdf/estimating-minimum-area-of-suitable-habitat-and-viable-population-size-for-the-northern-muriqui-brac#>.] The northern muriqui also suffers from very low genetic diversity
and is poorly understood, causing problems in conservation.
[Daniel, Brito.]
Lack of Adequate Taxonomic Knowledge May Hinder Endemic Mammal Conservation in the Brazilian Atlantic Forest
" Google Scholar. N.p., 2004. Web. 26 Oct. 2012. The estimated wild population of northern muriquis was raised from about 500 to 1000 individuals in 2005, due to new discoveries and research in other forests.
Predation
Northern muriqui can be preyed upon by
ocelots,
tayra, and some birds of prey. If a threat or predator is observed, a group of muriqui will vocally call out to warn others
Human evolution relevance
The northern muriqui has been argued to be important to understanding
human evolution
Human evolution is the evolutionary process within the history of primates that led to the emergence of ''Homo sapiens'' as a distinct species of the hominid family, which includes the great apes. This process involved the gradual development of ...
, since it is one of the few primates that has tolerant, nonhierarchial relationships among and between males and females, a feature shared with
hunter-gatherer
A traditional hunter-gatherer or forager is a human living an ancestrally derived lifestyle in which most or all food is obtained by foraging, that is, by gathering food from local sources, especially edible wild plants but also insects, fungi, ...
humans, but which contrasts with the ranked relationships of most other primates.
[Strier, K.B., Chaves, P.B., Mendes, S.L., Fagundes, V., Di Fiore, A. (2011). Low paternity skew and the influence of maternal kin in an egalitarian, patrilocal primate, PNAS, 108, 18915–18919 ] Group aggression is also rare.
The success of males fathering offspring links to the maternal investment they gain from their mothers and coresident female kin. This provides support to the
grandmother hypothesis
The grandmother hypothesis is a hypothesis to explain the existence of menopause in human life history by identifying the adaptive value of extended kin networking. It builds on the previously postulated " mother hypothesis" which states that as m ...
.
See also
*
Feliciano Miguel Abdala Private Natural Heritage Reserve, long thought to be the only place where these monkeys still survive
References
Gallery
External links
*ARKive
images and movies of the Northern muriqui ''(Brachyteles hypoxanthus)''
{{Taxonbar, from=Q559289
northern muriqui
The northern muriqui (''Brachyteles hypoxanthus)'' is one of two species of muriqui. They are also known as woolly spider monkey because they exhibit the woollen pelt of woolly monkeys and the long prehensile tail of spider monkeys. Muriquis are ...
Mammals of Brazil
Endemic fauna of Brazil
Fauna of the Atlantic Forest
Primates of South America
Critically endangered animals
Critically endangered biota of South America
northern muriqui
The northern muriqui (''Brachyteles hypoxanthus)'' is one of two species of muriqui. They are also known as woolly spider monkey because they exhibit the woollen pelt of woolly monkeys and the long prehensile tail of spider monkeys. Muriquis are ...
Taxa named by Heinrich Kuhl