Yellow-tailed Woolly Monkey (Lagothrix flavicauda)


MORPHOLOGY:
The yellow-tailed woolly monkey has a prehensile tail, which is lacking hair on the ventral side. The only form of sexual dimorphism for this species is the canines of the males being longer than that of the females. The females' clitoris is as long or longer than the males' penis, which makes identification in the wild difficult. This species has relatively short and robust arms and legs (Aquino and Encarnacion, 1994). The pelage color of this species is a copperish color that darkens to black at the lower back, base of the skull, and at the ends of the extremities (Leo Luna, 1982). The mouth of this species is surrounded by white colored fur and the ventral side of the lower third of the tail has a yellow band (Leo Luna, 1982). This species has a tuft of yellow or straw-colored hair on the pubic area that is longer in males (Mittermeier et al., 1977). In males this pubic tuft of hair can reach lengths of 15 centimeters (Leo Luna, 1987). The yellow pubic hair tuft and the yellow band on the tail are lacking in juveniles and infants (Mittermeier et al., 1977). The pelage of the yellow-tailed woolly monkey is longer and thicker than Humboldt's woolly monkey, Lagothrix lagotricha, this an adaptation to the colder montane forest habitat (Mittermeier et al., 1977). The pelage of this species is said to provide a perfect camouflage against the lighting of the forest canopy (Graves and O'Neill, 1980). The mean body mass for males is 8.3 kilograms and for females it is 5.7 kilograms (Ford and Davis, 1992; cited in Pastor-Nieto and Williamson, 1998).

RANGE:
The yellow-tailed woolly monkey is found in the country of Peru. This species lives in the montane cloud forests of Eastern Peru, and live in elevations from 500-2500 meters (Kinzey, 1997; Leo Luna, 1982; Leo Luna, 1986; Mittermeier et al., 1977). The habitats this species lives has the characteristics of steeply inclined terrain, fog, precipitation throughout the year, and trees that are usually less than or equal to 35 to 40 meters in height and have a dbh of 1 meter (Leo Luna, 1982). The yellow-tailed woolly monkey is found in the Rio Abiseo National Park in Peru (Butchart et al., 1995).

ECOLOGY:
The yellow-tailed woolly monkey is primarily frugivorous but leaves, flowers, buds, and petioles of Cecropia sp. also constitute an important part of the diet (Leo Luna, 1982). The fruits of Ficus spp. are an important part of the diet (Leo Luna, 1980). This species has also been observed to feed on fruit from a tree of a member of the family Melastomataceae (Parker and Barkley, 1981). This species also eats the pseudo-bulbs of epiphytes (Leo Luna, 1987). Lichen has also been found to be a part of the diet (Butchart et al., 1995). This species has been observed to forage on the buds of a Clusia sp. (Parker and Barkley, 1981). The yellow-tailed woolly monkey has also been known to raid maize, Zea mays, crops (Soini, 1982). This species is arboreal and diurnal. The yellow-tailed woolly monkey spends most of its time in the canopy and sub-canopy of the forest and ranging from heights of 8 to 15 meters above the ground (Butchart et al., 1995). The group size ranges from 4-14 individuals (Leo Luna, 1982). There are from 1 to 3 adult males in a group (Aquino and Encarnacion, 1994).

LOCOMOTION:
The yellow-tailed woolly monkey travels through the forest quadrupedally and uses its tail as a fifth arm (Fleagle, 1988). This species can leap distances of 15 meters (Butchart et al., 1995). This species also uses its tail to position itself when it feeds (Fleagle, 1988).

SOCIAL BEHAVIOR:
The yellow-tailed woolly monkey has a multi-male group social system. This species has a polygamous mating system (Kinzey, 1997). A hierarchy does exist amongst the males in the group (Kinzey, 1997). This species has been described to have low levels of competition amongst the members of a group (Leo Luna, 1980). This species has found to form mixed-species groups with Ateles sp. (Leo Luna, 1980). Humans, Homo sapiens, are probably the main predator of this species, hunting them for meat (Mittermeier et al., 1977). Another predator of the yellow-tailed woolly monkey is the puma, Felis concolor (Leo Luna, 1980).

VOCAL COMMUNICATION:
puppy-like noise: This is a call that sounds like a bark that may be heard for a great distance in the forest (Leo Luna, 1980). This call may be confused with calls made by Ateles sp. (Leo Luna, 1980).

OLFACTORY COMMUNICATION:
urine tasting: This is when an individual will smell and taste the urine with the tip of the tongue (Ramirez, 1988). This behavior is performed by an adult female to the urine of another adult female (Ramirez, 1988).

anogenital rubbing:This is when an individual will rub the anus against a surface in a circular motion (Ramirez, 1988). This behavior is performed by adult males and females and serves to function as a marking behavior (Ramirez, 1988). This behavior may be responded to by other conspecifics sniffing the area (Ramirez, 1988).

VISUAL COMMUNICATION:
cut-off: This is when an individual will turn the head sideways quickly, while sometimes lifting the chin and turning the back (Ramirez, 1988). This common behavior is performed by all members of the group and occurs towards conspecifics and humans (Ramirez, 1988). This is a submissive signal that functions in non-provocation (Ramirez, 1988).

branch shake: This when an individual will shake a tree branch (Ramirez, 1988).This common behavior is mostly performed by adult males and is seen in situations of the presence of an outside disturbance and during mating (Ramirez, 1988). This display functions to communicate a high threat by the sender and may be responded to by the rest of the group becoming alerted (Ramirez, 1988).

threat display: This is when an adult males will hang by the tail and have the arms outstretched (Ramirez, 1988). This common behavior is seen during situations of interspecific aggression (Ramirez, 1988). The display functions to communicate threat on the part of the sender (Ramirez, 1988).

anogenital rubbing:This is when an individual will rub the anus against a surface in a circular motion (Ramirez, 1988). This behavior is performed by adult males and females and serves to function as a marking behavior (Ramirez, 1988). This behavior may be responded to by other conspecifics sniffing the area (Ramirez, 1988).

genital display: This is when an individual with position the rear towards the observer and have the tail raised and shake the hips (Ramirez, 1988). This behavior is performed by adult males and is found in situations of interspecific aggression (Ramirez, 1988). This display is used to communicate threat (Ramirez, 1988).

hunched back: This is when an individual will hunch the shoulders, arches the back, and sometimes will protrude the lower lip (Ramirez, 1988). This behavior is performed by subadult males and is used to communicate threat (Ramirez, 1988).

walk with hunched back: This is when an individual will perform hunched back while walking and performing teeth-chattering (Ramirez, 1988). This behavior is performed by subadult males and is used to communicate threat (Ramirez, 1988).

bang objects: this is when a subadult males will bang objects (Ramirez, 1988). This behavior is used to communicate threat (Ramirez, 1988).

lower lip protruded: This is when an individual will protrude the lower lip and have the corners of the mouth drawn down (Ramirez, 1988). This behavior is performed by subadult males and serves to communicate threat (Ramirez, 1988).

teeth-chattering: This is when an individual will look at the receiver having the teeth exposed and chattered and females combine this with lip-smacking (Ramirez, 1988). This common behavior is performed by all members of the group and occurs with sobbing, snuffling, and sexual overtures (Ramirez, 1988). This behavior serves to promote contact and to communicate appeasement (Ramirez, 1988).

- TACTILE COMMUNICATION:
mouth-to-mouth contact: For the yellow-tailed woolly monkey this serves as a greeting behavior (Nishimura, 1990).

REPRODUCTION:
The yellow-tailed woolly monkey gives birth to a single offspring.

REFERENCES:
Aquino, R. and Encarnacion, F. 1994. Primates of Peru. Primate Report. Vol. 40, 1-127.

Burton, F. 1995. The Multimedia Guide to the Non-human Primates. Prentice-Hall Canada Inc.

Butchart, S.H.M., Barnes, R., Davies, C.W.N., Fernandez, M., and Seddon, N. 1995. Observations of two threatened primates in the Peruvian Andes. Primate Conservation. Vol. 16, 15-19.

Fleagle, J. G. 1988. Primate Adaptation and Evolution. Academic Press: New York.

Ford, S.M. and Davis, L.C. 1992. Systematics and body size: Implications for feeding adaptations in New World Monkeys. American Journal of Physical Anthropology. Vol. 88, 415-468.

Graves, G.R. and O'Neill, J.P. 1980. Notes on the yellow-tailed woolly monkey (Lagothrix flavicauda) of Peru. Journal of Mammalogy. Vol. 61(2), 345-347.

Kinzey, W.G. 1997. Lagothrix. in New World Primates: Ecology, Evolution, and Behavior. ed. Warren G. Kinzey, Aldine de Gruyter, New York.

Leo Luna, M. 1980. First Field Study of the Yellow-tailed Woolly Monkey. Oryx. Vol. 15, 386-389.

Leo Luna, M. 1982. Conservation of the Yellow-tailed Woolly Monkey, Lagothrix flavicauda. International Zoo Yearbook. Vol. 22, 47-52.

Leo Luna, M. 1986. Primate conservation in Peru: The yellow-tailed woolly monkey in the Northern Peruvian Andes, a case study. Primate Report. Vol. 14, 160.

Leo Luna, M. 1987. Primate Conservation in Peru: A Case Study of the Yellow-tailed Woolly Monkey. Primate Conservation. Vol. 8, 122-123.

Mittermeier, R.A., de Macedo-Ruiz, H., Luscombe, B.A., and Cassidy, J. 1977. Rediscovery and conservation of the Peruvian yellow-tailed woolly monkey (Lagothrix flavicauda). in Primate Conservation. eds. H.S.H. Prince Rainier III of Monaco and G.H. Bourne. Academic Press: New York.

Nishimura, A. 1990. Mating Behavior of Woolly Monkeys (Lagothrix lagotricha) at La Macarena, Colombia (II): Mating Relationships. Field Studies of New World Monkeys, La Macarena, Colombia 3, 7-12.

Parker, T.A. and Barkley, L.J. 1981. New locality for the yellow-tailed woolly monkey. Oryx. Vol. 16, 71-72.

Pastor-Nieto, R. and Williamson, D.K. 1998. The effect of rainfall seasonality on the geographic distribution of neotropical primates. Neotropical Primates. Vol. 6(1), 7-14.

Ramirez, M. 1988. The woolly monkeys, genus Lagothrix. in Ecology and Behavior of Neotropical Primates Vol. 2. eds. R.A. Mittermeier, A.B. Rylands, A.F. Coimbra-Filho, G.A.B. da Fonseca. World Wildlife Fund: Washington, D.C.

Soini, P. 1982. Primate conservation in Peruvian Amazonia. International Zoo Yearbook. Vol. 22, 37-47.

Last Updated: May 13, 2007.
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