Geographic Range
Ateles fusciceps , the Brown-headed Spider Monkey, can be found from Central America to northern South America (Primate Gallery 2000).
Habitat
Brown-headed Spider Monkeys are found in the rainforests of Central and South America. The majority of their time is spent in the uppermost branches of trees, foraging for food. Most climates allow them to live year-round in the same area. However, in drier habitats, they must travel up 18 km (10 mi.) each day in search of food(Microsoft Encarta 2000).
- Terrestrial Biomes
- rainforest
Physical Description
Brown-headed Spider Monkeys have long, narrow limbs and a prehensile tail that is used as a fifth limb to swing between branches as they forage for food. Their tail is much longer in length than their body. The tail measures 70 to 85 cm (28 to 34 in.) while the body ranges from 40 to 55 cm (16 to 22 in.). The average weight for both the male and female is approximately 9 kg (20 lbs.). Brown-headed Spider Monkeys can be separated into two subspecies. The subspecies A. f. fusciceps has a brownish-black body with a brown head. A. f. robustus is completely black except for a few white strands of hair on the chin. Their coat is long and shaggy, usually with a lighter underside. A white ring surrounds each eye. Their skull is structured so that they have forward facing eyes which allow them to precisely gauge distances as they swing from tree to tree. The hands and feet of A. fusciceps are adapted for climbing. Brown-headed Spider Monkey species lacks a thumb, which increases the strength of their grip and helps with climbing (Sleeper 1997; Napier 1985).
- Other Physical Features
- endothermic
- bilateral symmetry
Reproduction
Brown-headed spider monkeys indicate that they are prepared to mate through changes in behavior, scents, and visual signals. The estrous cycle is 26 days and females will usually associate with a male for up to three days, with mating lasting between 5 to 10 minutes.
Female Brown-headed Spider Monkeys reach sexual maturity at 51 months. Usually a single offspring is produced and, once born, the young will be cared for only by the mother until weaned at 20 months. On average, Brown-headed Spider Monkeys have a life span of 24 years. (Fleagle 1998; Microsoft Encarta 2000; Sleeper 1997).
- Key Reproductive Features
- iteroparous
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
Only the female cares for her young, until it is weaned at 20 months. Male brown-headed spider monkeys live in their natal groups for their entire life. Females will disperse at adolescence.
- Parental Investment
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
- post-independence association with parents
Lifespan/Longevity
Behavior
Brown-headed spider monkeys are active during the day, sleep at night, and spend most of their time in the trees. These monkeys associate in loose groups of about 20 individuals, but it is rare to find them gathered in one place. Individuals drift between subgroups of varying sizes. They move through the forest using both their hands and feet to swing between trees, and walk in an upright position along branches. Brown-headed Spider Monkeys can leap in excess of 9 meters (30 ft.) from branch to branch (Fleagle 1998; Kinzey 1997; Microsoft Encarta 2000; Napier 1985).
Communication and Perception
Food Habits
Brown-headed Spider Monkeys prefer ripe fruits and leaves, but will eat nuts, seeds, insects, and sometimes eggs. The climate of the rainforests in which they live ensures an abundant supply of food year-round, allowing them to be able to reside in the same area throughout the year (MacDonald 1999; Microsoft Encarta 2000).
- Animal Foods
- eggs
- insects
- Plant Foods
- leaves
- seeds, grains, and nuts
- fruit
Economic Importance for Humans: Positive
In some areas Brown-headed Spider Monkeys may be hunted for food.
Economic Importance for Humans: Negative
There are no negative effects of Brown-headed Spider Monkeys.
Conservation Status
One of the main reasons Brown-headed Spider Monkeys are declining in numbers is due to deforestation of their habitat. Some of the monkeys are able to survive in areas that have been partially logged, but few can live where rainforests have been completely removed.(Microsoft Encarta 2000).
Additional Links
Contributors
Bryan Cifranic (author), Fresno City College, Carl Johansson (editor), Fresno City College.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- social
-
associates with others of its species; forms social groups.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- folivore
-
an animal that mainly eats leaves.
- frugivore
-
an animal that mainly eats fruit
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
References
Bourne, , Geoffrey H. 1974. Primate Odyssey . New York: G.P. Putnam's Sons.
Flannery, S. 2000. "Brown-headed Spider Monkey" (On-line). Accessed February 11, 2001 at http://www.primate.wisc.edu/pin/factsheets/ateles_fusciceps.html .
Fleagle, J. 1999. Primate Adaptations and Evolution . San Diego: Academic Press.
Hershkovitz, P. 1977. Living New World Monkeys (Platyrrhini) with an Introduction to Primates, Vol 1 . Chicago: University of Chicago Press.
Kinzey, W. 1997. Ateles. in New World Primates: Ecology, Evolution, and Behavior. ed. Warren G. Kinzey . New York: Aldine de Gruyter.
MacDonald, D. 1999. The Encyclopedia of Mammals . London: Andromeda Oxford Limited.
Microsoft Encarta Online Encyclopedia, 2000. "Monkey (animal)" (On-line). Accessed February 8, 2001 at http://encarta.msn.com/find/Concise.asp?z=1&pg=2&ti=761569669 .
Microsoft Encarta Online Encyclopedia, 2000. "Spider Monkey" (On-line). Accessed February 8, 2001 at http://encarta.msn.com/find/Concise.asp?z=1&pg=2&ti=761565356 .
Napier, J. 1985. The Natural History of the Primates . Massachusetts: The MIT Press.
Preston-Mafhan, R. 1992. Primates of the World . New York: Facts on File, Inc..
Primate Gallery, 2000. "Spider Monkeys and Woolly Monkeys" (On-line). Accessed March 8, 2001 at http://www.selu.com/bio/PrimateGallery/primates/Cebidae/Atelinae.html .
Rowe, N. 1996. The Pictorial Guide to Living Primates . New York: Pogonias Press.
Sleeper, B. 1997. Primates: The Amazing World of Lemurs, Monkeys, and Apes . San Francisco: Chronicle Books.