Brazilian bare-faced tamarins are an arboreal species that prefers secondary forests, swamps, edge and white sand forests. They are usually found from 10 to 12 meters up in the canopy. (Rowe, 1996)
Brazilian bare-faced tamarins are named for their black, hairless face and ears contrasted with variable fur colors such as brown, black, or silver, depending on the subspecies. Body length ranges from 208 to 283 mm and tail length is 335 to 420 mm. Weight in both males and females averages 430 g. These primates have non-opposable thumbs with claw-like digits, except for the first digit on each toe. The dental formula is 2/2-1/1-3/3-2/2=32 teeth. Canines are larger than incisors. (Nowak, 1999; Rowe, 1996)
Usually only the dominant female in a social group will mate. Other females are unable to ovulate as long as the dominant female's pheromones are present. Although usually only the dominant female in a social group breeds, it is not known which males participate in breeding, and whether the species is polyandrous. It should be noted, however, that in other species of this genus, the dominant female has been observed copulating with more than one adult male, and given other similarities between all tamarins, it is likely that S. bicolor shows some degree of polyandry. (Goldizen, 1987; Nowak, 1999; Snowdon and Soini, 1988)
Eighty percent of births are twins, with litter weights ranging from 14.1 to 23.5% of the maternal weight. Within the genus Saguinus, it is common for the father as well as other members of the group to assist in the care, grooming, carrying, and feeding of young. (Goldizen, 1987; Nowak, 1999)
Generally, within the genus Saguinus, the young are born fully furred, but helpless. However, they are able to cling to their parents. The young are able to explore their environment on their own by about 21 days of age, but they continue to ride on their parents until they are 6 or 7 weeks old. Solid foods may be ingested by the young as early as 4 weeks of age, although nursing can continue much longer. (Nowak, 1999; Nowak, 1999)
Females have an estrous cycle of approximately 15 days in this genus. Gestation lengths for these tamarins have been reported as around 140-150 days. Females reach reproductive maturity around 18 months of age, and males reach reproductive maturity around 2 years of age. It is reasonable to suspect that S. bicolor is similar to its congeners in these respects. (Nowak, 1999)
Parental care in tamarins is somewhat unique among primates, in that males provide a great deal of it. Both parents provide general care for their young, but the males usually carry them. Males transfer the young back to the mother every couple of hours to nurse. It is thought that the energetic demands of lactation and carrying such relatively heavy twin offspring are just too much for a single mother to manage. (Goldizen, 1987; Nowak, 1999; Price, et al., 2001; Rowe, 1996)
From birth until 20 weeks of age, juveniles are given solid food by both parents, although fathers take the lead in providing such food for the young. Self-feeding is dominant after this period. (Goldizen, 1987; Nowak, 1999; Price, et al., 2001; Rowe, 1996)
It is interesting to examine the communal care of offspring in tamarin species with regard to the polyandrous mating system noted in some species. It may be that this system has evolved because the energetic burden of reproduction in these small animals, which subsist mainly on high quality fruit and insect foods, is so very great. Because the young weigh so much, grow rapidly, and need a lot of milk, a mother is not able to carry the twins, and simultaneously obtain enough food to maintain both herself and her milk supply. In order to ensure that the offspring have a good chance of survival, a male may benefit by allowing another male to mate with a female (thereby reducing certainty of paternity) but providing an additional "father" to share the responsibilities of rearing the young. This may increase survivorship of the young tamarins. (Goldizen, 1987)
Nonreproductive individuals in tamarin social groups have also been seen to care for young, although at a lower frequency than parents. This sort of alloparental behavior may benefit the helpers by giving them valuable experience in the care of the young, and also in ensuring the survival of siblings or other close relatives. Although not specifically reported for S. bicolor, it is likely that some of this helping behavior occurs. (Goldizen, 1987)
Although the longevity of S. bicolor has not been reported, members of this genus may live as long as 25 years in captivity. It is likely that S. bicolor is similar. Lifespan in the wild is probably significantly shorter. (Nowak, 1999)
Locomotion is quadrupedal with leaping and clinging between branches. Social behavior includes multimale/multifemale family groups of two to eight, including a dominant female. (Rowe, 1996; Snowdon and Soini, 1988)
Saguinus bicolor occupies the smallest homerange of any Amazon primate, about 12 ha. (Rowe, 1996)
Chemical communication in tamarins is more complex. Supapubic/sternal marking is used by rubbing the sternal gland in the anogenital region against branches. Two forms of sternal marking are used, depending on how excited and individual is. (Rowe, 1996; Rowell, 1972)
In addition to vocal and chemical communication, primates have complex tactile communication. Grooming is an important part of their behavior. In addition, tactile communication between mates, parents and offspring, and rivals probably occur in other contexts. (Nowak, 1999)
Because these animals are diurnal and social, it is likely that they also use some visual signals in their communication. Body postures and movements probably signify intentions and desires to other tamarins.
The fruits or flowers of 21 plants compose 96.1% of the plant component of the diet, along with tree exudates. Small animal prey, including insects, and seedpod gums are consumed during the dry season. A stealthy approach is used to hunt and capture large insects on leaves and branches. While they feed at all canopy heights, from the ground to over 20 meters, they prefer heights of 10 to 12 meters. (Kinzey, 1997; Rowe, 1996)
Predators of Brazilian bare-faced tamarins are predominately humans, through the expanding city of Manaus. (Rowe, 1996)
Little is known about the ecosystem roles of the bicolored tamarins. They may help to pollinate and disperse seeds by eating fruits, nectars, and seedpod gums from various plants and trees.
Brazilian bare-faced tamarins are utilized for food in the region of Manaus. (Rowe, 1996)
There are no known adverse affects of S. bicolor on humans.
Brazilian bare-faced tamarins are listed as threatened species under the US Endangered Species Act, and are on CITES Appendix II.
Nancy Shefferly (editor), Animal Diversity Web.
Rachel Kutschera (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
Referring to an animal that lives in trees; tree-climbing.
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.
uses smells or other chemicals to communicate
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
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.
union of egg and spermatozoan
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
an animal that mainly eats fruit
An animal that eats mainly plants or parts of plants.
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).
Having one mate at a time.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
chemicals released into air or water that are detected by and responded to by other animals of the same species
Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).
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.
specialized for leaping or bounding locomotion; jumps or hops.
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
uses touch to communicate
Living on the ground.
The term is used in the 1994 IUCN Red List of Threatened Animals to refer collectively to species categorized as Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), or Insufficiently Known (K) and in the 1996 IUCN Red List of Threatened Animals to refer collectively to species categorized as Critically Endangered (CR), Endangered (EN), or Vulnerable (VU).
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
breeding takes place throughout the year
Philadelphia Zoo. 2002. "At the Zoo. Facts & Furs--Animal Profiles" (On-line). Philadelphia Zoo. Accessed October 22, 2002 at http://www.phillyzoo.org/at/profiles.asp.
Goldizen, A. 1987. Tamarins and marmosets: Communal care of offspring. Pp. 34-43 in B Smuts, D Cheyney, R Seyfarth, R Wrangham, T Struhsaker, eds. Primate Societies. Chicago an London: The University of Chicago Press.
Kinzey, W. G. 1997. New World Primates: Ecology, Evolution, and Behavior. New York: Warren G. Kinzey, Aldine de Gruyter.
Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore and London: The Johns Hopkins University Press.
Price, E., C. Feistner, T. Anna. 2001. Food-sharing in pied bare-faced tamarins (Saguinus bicolor bicolor): development and individual differences. International Journal of Primatology, 22(2): 231-241.
Rowe, N. 1996. The Pictoral Guide to Living Primates. New York: Pogonia Press.
Rowell, T. 1972. The Social Behavior of Monkeys. Middlesex, England: Penguin Books, Ltd.
Smuts, B., D. Cheney, R. Seyfarth. 1987. Primate Societies. Chicago: University of Chicago Press.
Snowdon, C., Soini. 1988. The tamarins, genus Saguinus . Ecology and Behavior of Neotropical Primates, 2: 223-298.