Geographic Range
Native to the Brazilian rainforest,
Saguinus bicolor
is found in a small region north of the Amazon River.
- Biogeographic Regions
- neotropical
Habitat
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.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- forest
- rainforest
- Wetlands
- swamp
Physical Description
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.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
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.
- Mating System
- monogamous
- polyandrous
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.
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.
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.
- Key Reproductive Features
- iteroparous
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- viviparous
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.
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.
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.
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.
- Parental Investment
- altricial
-
pre-fertilization
-
protecting
- female
-
protecting
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- male
- female
-
protecting
- male
- female
-
provisioning
-
pre-independence
-
provisioning
- male
- female
-
protecting
- male
- female
-
provisioning
- post-independence association with parents
- extended period of juvenile learning
Lifespan/Longevity
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.
Behavior
Locomotion is quadrupedal with leaping and clinging between branches. Social behavior
includes multimale/multifemale family groups of two to eight, including a dominant
female.
- Key Behaviors
- arboreal
- saltatorial
- diurnal
- motile
- social
- dominance hierarchies
Home Range
Saguinus bicolor
occupies the smallest homerange of any Amazon primate, about 12 ha.
Communication and Perception
Like other primates, communication in this species involves many different channels.
Vocal communication consists of whistles and chirps.
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.
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.
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.
- Other Communication Modes
- pheromones
- scent marks
Food Habits
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.
- Animal Foods
- insects
- terrestrial non-insect arthropods
- Plant Foods
- leaves
- seeds, grains, and nuts
- fruit
- flowers
- sap or other plant fluids
Predation
Predators of Brazilian bare-faced tamarins are predominately humans, through the expanding
city of Manaus.
Ecosystem Roles
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.
- Ecosystem Impact
- disperses seeds
- pollinates
Economic Importance for Humans: Positive
Brazilian bare-faced tamarins are utilized for food in the region of Manaus.
- Positive Impacts
- food
Economic Importance for Humans: Negative
There are no known adverse affects of S. bicolor on humans.
Conservation Status
Brazilian bare-faced tamarins are listed as threatened species under the US Endangered Species Act, and are on CITES Appendix II.
Additional Links
Contributors
Nancy Shefferly (editor), Animal Diversity Web.
Rachel Kutschera (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- 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.
- swamp
-
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
- 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.
- monogamous
-
Having one mate at a time.
- polyandrous
-
Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).
- 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).
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- altricial
-
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.
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- saltatorial
-
specialized for leaping or bounding locomotion; jumps or hops.
- 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.
- dominance hierarchies
-
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- pheromones
-
chemicals released into air or water that are detected by and responded to by other animals of the same species
- scent marks
-
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- food
-
A substance that provides both nutrients and energy to a living thing.
- threatened
-
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).
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
References
Goldizen, A. 1987. Tamarins and marmosets: Communal care of offspring. Pp. 34-43 in 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.
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 .