The bald uakari (''Cacajao calvus'') or bald-headed uakari is a small

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 ...

characterized by a very short tail; bright, crimson face; a bald head; and long coat. The bald uakari is restricted to

várzea forest A várzea forest is a seasonal floodplain forest inundated by whitewater rivers that occurs in the Amazon biome. Until the late 1970s, the definition was less clear and várzea was often used for all periodically flooded Amazonian forests. Althoug ...

s and other wooded habitats near water in the western

Amazon Amazon most often refers to: * Amazon River, in South America * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon (company), an American multinational technology company * Amazons, a tribe of female warriors in Greek myth ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

and

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

Taxonomy

There are four recognized

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of the bald uakari, each of which is considered vulnerable to extinction: * White bald-headed uakari, ''Cacajao calvus calvus'' * Ucayali bald-headed uakari, ''Cacajao calvus ucayalii'' * Red bald-headed uakari, ''Cacajao calvus rubicundus'' * Novaes' bald-headed uakari, ''Cacajao calvus novaesi'' However, a literature review of all known occurrence records, followed by a molecular phylogenetic analysis, suggests that these subspecies should be upgraded to species, as well as adding a new species, ''Cacajao amuna'' sp. n. If this is accepted by the wider research community, it could have large implications for the conservation status of the five species, for example with ''C. novaesi'' and ''C. amuna'' having small ranges at particular risk from deforestation.

Description

The bald uakari weighs between 2.75 and 3.45 kg (6.1 and 7.6 lb), with head and body lengths average 45.6 cm (18.0 in) (male) and 44.0 cm (17.3 in) (female). In general, the bald uakari has a long, shaggy coat ranging from white in color to red and its head is bald. The tail is bob-like and rather short for a New World monkey (about , at only half the length of the body and head combined. Its scarlet red face is due to the lack of skin pigments and plentiful capillaries that run under its facial tissue.

Behaviour and ecology

The

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 ...

bald uakari prefers to reside in seasonally flooded forests in the area of the

Amazon River Basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...

, in the countries of

and

. It is important that the uakari is arboreal (lives in the tree tops) because of the

flood A flood is an overflow of water (list of non-water floods, or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are of significant con ...

ing of the forests and the water rising to great heights during the rainy season. During the dry season, it returns to the ground to look for seeds and other food material. A study of the diet of the uakari found it to consist of 67% seeds, 18% fruit, 6% flowers, 5% animal prey, and buds. Its powerful lower jaw forms a pseudodental comb, which allows the uakari to open the hard surfaces of unripe fruits and eat the nuts that most other primates would not be able to open. It will also eat insects that happen to cross its path, however it does not specifically pursue this type of food. The bald uakari can be found traveling up to 4.8 kilometers per day in multi-male/multi-female groups of 5 to 30 individuals, and even up to 100. It can be extrapolated from the general primate behavior of female philopatry that female uakaries are also philopatric. This means that males leave the natal group. The total size of the group's home range is between 500 and 600 hectares. This requires efficient territorial defense mechanisms. A few of these include specific vocalizations, wagging of the tail, and erection of the hair. The bright red facial skin is a sign of good health and allows for the determination of a healthy mate. The breeding season is between October and May. Its

gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

period is approximately six months. Both sexes have a sternal gland, which might be involved in

olfactory communication Olfactic communication is a channel of nonverbal communication referring to the various ways people and animals Communication, communicate and engage in social interaction through their sense of Sense of smell, smell. Our human Olfactory system ...

, especially during mating, when the female encourages the male to mate by releasing an attractive scent. The bald uakari lives approximately 30 years and has been known to live over 30 years in captivity. Due to the uakari's location, it is extremely common for these animals to contract malaria. Primates who have contracted the disease are noticeably paler and are not chosen as sexual partners as they do not have the desired natural immunity to malaria.

Conservation

The conservation status of this species was changed from near threatened to vulnerable in the 2008

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 ...

because the species has declined at least 30% over the past 30 years (three generations) due to

hunting Hunting is the Human activity, human practice of seeking, pursuing, capturing, and killing wildlife or feral animals. The most common reasons for humans to hunt are to obtain the animal's body for meat and useful animal products (fur/hide (sk ...

and

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 ...

. This is considerably better than the 1994 assessment which found it to be endangered, followed by the 2003 assessment which found the species to be near threatened. Although the conservation status has improved, actual population numbers are on a decreasing trend. Since it only lives in white water flooded forests, it is very susceptible to human impact (i.e. land acquisition for agriculture and/or pastures). Male uakari

Forest loss and hunting are the two most prominent threats to the bald uakari. Between 1980 and 1990 it was found that an average of 15.4 million hectares of tropical forests were destroyed each year and the Neotropics are facing forest loss in areas such as the southern and eastern parts of the Amazonia. In 1997, the Amazon Basin experienced the highest rate of forest destruction of the remaining tropical rainforests worldwide. Logging of hardwoods is a major contributor to overall destruction as large-scale logging disrupts the continuity of forest canopies.

Canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an a ...

disruption and forest loss directly affect uakaris because of their arboreal lifestyle and adaptations for seed food consumption. Additionally, ''Cacajao calvus'' populations are located so close to the Amazon River that there is a higher risk of human hunting from

canoe A canoe is a lightweight, narrow watercraft, water vessel, typically pointed at both ends and open on top, propelled by one or more seated or kneeling paddlers facing the direction of travel and using paddles. In British English, the term ' ...

s and such to use the primates as a food source or bait. Cacajao calvus Amazonia

Conservation organisations

In 1999, the Pilot Program to Conserve the Brazilian

Rainforest Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

, set forth by the

World Bank The World Bank is an international financial institution that provides loans and Grant (money), grants to the governments of Least developed countries, low- and Developing country, middle-income countries for the purposes of economic development ...

, aimed to place a total of 350 million dollars from Germany, Britain, and other major industrialized communities into conservation programs for the Amazon. Conservation efforts have also been initiated by Wildlife Conservation Society representatives working in South America. The Amazon-Andes Conservation Program (AACP) was established in 2003 in order to protect a set of seven landscapes in the Amazon. These protected landscapes account for approximately three percent of the Amazon Basin. The Wildlife Conservation Society is planning on expanding to more landscapes in the near future. Along with the AACP, Brazil's national environment agency, the Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (IBAMA) is gaining help from the army to patrol the Amazon for acts of

illegal logging Illegal logging is the harvest, transportation, purchase, or sale of timber in violation of laws. The harvesting procedure itself may be illegal, including using corrupt means to gain access to forests; extraction without permission, or from a p ...

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

, and

deforestation Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. Ab ...

References

External links

* ARKive
images and movies of the bald-headed uakari ''(Cacajao calvus)''

The Red Uakari Monkey Project
, retrieved March 26, 2009

{{Taxonbar, from=Q377612

bald uakari The bald uakari (''Cacajao calvus'') or bald-headed uakari is a small New World monkey characterized by a very short tail; bright, crimson face; a bald head; and long coat. The bald uakari is restricted to várzea forests and other wooded habita ...

Mammals of Peru Primates of Brazil

Taxa named by Isidore Geoffroy Saint-Hilaire