The bald uakari (Cacajao calvus) or bald-headed uakari is a small New World monkey characterized by a very short tail, a bright, crimson face, bald head, and long coat. The bald uakari is restricted to várzea forests and other wooded habitats near water in the western Amazon of Brazil and Peru. 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

thumb|left|A skull of male red uakari (C. c. rubicundus) at [[Museum of Zoology of the University of São Paulo]]

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. Its scarlet red face is due to the lack of skin pigments and plentiful capillaries that run under its facial tissue. 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.

The bald uakari can be found traveling up to 4.8 kilometers per day 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 breeding season is between October and May. Its gestation period is approximately six months.

Conservation

thumb|Novae's bald-headed uakari (C. c. novaesi) in the [[Brazilian Amazon.]]

The conservation status of this species was changed from near threatened to vulnerable in the 2008 IUCN Red List because the species has declined at least 30% over the past 30 years (three generations) due to hunting and habitat loss. 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 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 canoes and such to use the primates as a food source or bait. 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.

References

  • ARKive - images and movies of the bald-headed uakari (Cacajao calvus)
  • The Red Uakari Monkey Project , retrieved March 26, 2009
  • Bald uakari with malaria (vid)