1. Profile (Picture)
2. Tidbits
3. Status and Trends (IUCN Status, Countries Where
Currently Found, Population Estimates, History of Distribution, Threats and Reasons
for Decline)
4. Data on Biology and Ecology (Size
and Weight, Habitat, Age to Maturity, Gestation
Period, Birth Season, Birth Rate, Diet,
Behavior, Social Organization)
5. References
Pictures: Yellow-tailed Woolly Monkey #1 (8 Kb JPEG) (Kids Ecol. Corps); Yellow-tailed Woolly Monkey #2 (16 Kb JPEG) (CNN); Yellow-tailed Woolly Monkey #3 (199 Kb GIF) (Primate Info Net)
The hair of the yellow-tailed woolly monkey is long and thick, an adaptation to its cold montane forest habitat. Its color is deep mahogany, with yellow on the underside of the rear surface of the tail and a whitish patch on the muzzle. The average weight is 5.7 kg (12.5 lb) for females and 8.3 kg (18.3 lb) for males. The yellow-tailed woolly monkey lives in the montane cloud forests of the Peruvian Andes at elevations of 1700 - 2500 m (5600' - 8200'), where there are steep gorges and ravines. Its diet is primarily frugivorous, but leaves, flowers, and buds are also eaten. The yellow-tailed woolly monkey is arboreal and diurnal. It has a multi-male group social system and a polygamous mating system. Apparently the competition among group members is at a low level.
Alexander von Humboldt was the first Western scientist to observe the yellow-tailed woolly monkey, in 1802. Other than 5 specimens that were collected in 1925 and 1926, nothing further was reported about this monkey until it was observed by an expedition in 1974. It is known to occur only in a few locations in the montane cloud forests of Eastern Peru.
The inaccessibility of its habitat protected the species until the 1950's. However, the construction of new roads; habitat loss and fragmentation from agriculture, logging and cattle ranching; and subsistence hunting; together with the monkey's naturally low population densities, slow maturation, low reproductive rate, and a restricted geographic distribution have led to this species' current critically endangered status.
*** The yellow-tailed woolly monkey is one of the world's rarest mammals.
*** The yellow-tailed woolly monkey seems unable to adapt to secondary forest, making it particularly vulnerable to habitat degradation (Butchart et al 1995).
*** Woolly monkeys have powerful prehensile tails, the lower third of which is covered on the bottom with fingerprint-type ridges that aid its grip (Napier & Napier 1985).
2004: Occurs in Peru (IUCN 2004).
[Note: Figures given are for wild populations only.]
Alexander von Humboldt was the first Western scientist to record the yellow-tailed woolly monkey, in 1802. Nothing further was reported about this monkey until two specimens were collected in 1925 and three in 1926. Nothing was heard of this species again until it was rediscovered by an expedition in 1974, thereby calming fears that it had become extinct. The populations discovered in 1974 were found in northeastern Cajamarca, southern Amazonas and northwestern San Martin in the Andes of northern Peru, all in the same general area where it had previously been found (Mittermeier et al. 1975). As of 2000 it was known to occur only in a few locations in the montane cloud forests of the Peruvian Andes.
Distribution
Map #1 (16 Kb) (InfoNatura)
Distribution Map #2 (214 Kb JPEG) (Inst.
Ciên. Biol.)
The inaccessibility of its habitat protected the species until the 1950's. However, the construction of new roads; habitat loss and fragmentation from agriculture, logging and cattle ranching; and subsistence hunting; together with the monkey's naturally low population densities, slow maturation, low reproductive rate, and a restricted geographic distribution have led to this species' current critically endangered status.
The average weight of the yellow-tailed woolly monkey is 5.7 kg (12.5 lb) for females and 8.3 kg (18.3 lb) for males (Flannery 2001). The head and body length and the tail length are both somewhat longer than 0.5 m (1.5').
The yellow-tailed woolly monkey lives in the montane cloud forests of the Peruvian Andes at elevations of 1700 - 2500 m (5600' - 8200') (IUCN 2003a) and at temperatures of 4 - 25 deg C (39 - 77 deg F) (Rowe 1996). The habitats where this species lives have the characteristics of steep gorges and ravines, fog, precipitation throughout the year, and trees that are usually no more than 40 m (130') high and 1 m (3.3') in diameter (Flannery 2001).
The yellow-tailed woolly monkey is one of the species that live in the Tropical Andes Biodiversity Hotspot (Cons. Intl.).
4 years (Luna 1980).
The gestation period for woolly monkeys is approximately 223 days (Macdonald 2001).
To date, births in woolly monkeys have not been observed to be seasonal (Macdonald 2001).
The time between births in woolly monkeys is about 1.5 - 2 years (Macdonald 2001). The yellow-tailed woolly monkey gives birth to a single offspring (Flannery 2001).
The yellow-tailed woolly monkey is primarily frugivorous, but leaves, flowers, and buds also constitute an important part of the diet. Lichens are sometimes eaten. (Flannery 2001)
The yellow-tailed woolly monkey is arboreal and diurnal, spending most of its time in the canopy and sub-canopy of the forest at heights of 8 - 15 m (26 - 49') above the ground. It is able to leap distances of 15 m (49') (Flannery 2001). Its movement patterns are basically quadrupedal, assisted by the prehensile tail, with some brachiation (Napier & Napier 1985).
The yellow-tailed woolly monkey has a multi-male group social system and a polygamous mating system. A hierarchy does exist among the males in a group, with one male dominant, but apparently the competition among group members is at a low level. The group size ranges from 4 - 14 individuals, including from 1 to 3 adult males. (Flannery 2001)
Burton & Pearson 1987, Butchart et al 1995, CNN, Cons. Intl., Emmons & Feer 1997, Flannery 2001, InfoNatura, Inst. Ciên. Biol., IUCN 1994, IUCN 1996, IUCN 2000, IUCN 2003a, IUCN 2004, Kids Ecol. Corps, Luna 1980, Macdonald 2001, Mittermeier et al. 1975, Napier & Napier 1985, Nowak & Paradiso 1983, Nowak 1999, Parker & Barkley 1981, Peres 1991, Primate Info Net, Rowe 1996, Rylands et al. 1997
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