By Valerie Ackley
Geographic Range
Black-pencilled marmosets are found in the Neo-tropical gallery forests of the Brazilian Central Plateau. They live along the Brazillian coast ranging from Bahia to Sao Paulo, and as far inland as Goias, between 14 and 17 degrees S. (Boudet, 2004; Elliot, 1913; Miranda and Faria, 2001)
Biogeographic Regions:
neotropical
(native
).
Habitat
Black-pencilled marmosets live in rainforests, usually residing high in the trees, under the canopy. Marmosets have rarely been observed at or near ground level. (Barros, Alencar, and Tomaz, 2004; Miranda and Faria, 2001)
These animals are found in the following types of habitat:
tropical
; terrestrial
.
Terrestrial Biomes:
rainforest
.
Physical Description
(15.98 oz)
(9 to 11 in; avg. 10 in)
Black-pencilled marmosets typically have some sparse white hairs on their faces, with a dark brown or black head. Their upper body and limbs are gray and their rump is usually black. The marmosets' undersides are black with a gray abdomen. Their tail is ringed with black and white and is not prehensile, but is used for balance. They are characterized by the black tufts around their ears. Black-pencilled marmosets do not have an opposable thumb and their nails tend to have a claw-like appearance. (Boudet, 2004; Elliot, 1913; Rosenberg, 2004)
Some key physical features:
endothermic
; heterothermic
; homoiothermic; bilateral symmetry
.
Sexual dimorphism:
male larger.
Reproduction
Black-pencilled marmosets usually breed twice a year
Black-pencilled marmosets are monogamous and typically live in family groups which include the reproducing couple and their offspring. (Miranda and Faria, 2001)
Mating systems:
monogamous
.
Black-pencilled marmosets breed twice a year and produce between 1 and 4 offspring, however they generally have twins. The gestation period is 150 days and offspring wean at about 8 weeks. The marmosets reach sexual maturity at approximately 18 months old. However, they typically mate very late. (Guerra, Takase, and Santos, 1998; Rosenberg, 2004)
Key reproductive features:
seasonal breeding
; gonochoric/gonochoristic/dioecious (sexes separate); sexual
; fertilization
; viviparous
.
There is considerable parental investment by both parents; infants are extremely dependent on their parents. The offspring are raised with the aid of other juvenile siblings. Offspring are weaned at 8 weeks and then taught to search for food. (Guerra, Takase, and Santos, 1998; Miranda and Faria, 2001; Rosenberg, 2004)
Parental investment:
pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: male, female, protecting: male, female); pre-independence (provisioning: male, female, protecting: male, female); post-independence association with parents; extended period of juvenile learning; inherits maternal/paternal territory.
Lifespan/Longevity
The life-span of a wild black-pencilled marmoset is unknown, however the average lifespan in captivity is 15 years. (Rosenberg, 2004)
Behavior
Black-pencilled marmosets are diurnal and live in groups of 2-14, which typically consist of a reproductive couple and their offspring. Offspring are cared for by both the mother and father, as well as older siblings in the family. As twins are very common among marmosets, additional support for the mother is often required. Though they live in small family groups, they often share sap trees with many other families in their species. They do engage in scent marking, but it is believed this is to deter other species from entering the area, and not other groups of their own species. Black-pencilled marmosets also appear to be migratory, moving throughout the forests as seasons become dry or wet, however it is unknown how far their migration extends. (Barros, Alencar, and Tomaz, 2004; Lacher et al., 1981)
Communication and Perception
The communication of black-pencilled marmosets has not been fully studied, however, it is believed that they communicate mostly through vocalizations. They appear to have predator-specific cries when they are threatened and have many vocalizations in addition to predator warnings. Black-pencilled marmosets also use scent marking, though it is unclear whether this is a form of communication, as many different family groups simply ignore the markings that another family group has left. (Barros, Alencar, and Tomaz, 2004; Lacher et al., 1981)
Other communication keywords:
scent marks
.
Food Habits
Black-pencilled marmosets commonly feed on tree sap. During food shortages or droughts their diet also includes fruit and insects, and they have even been known to eat various arthropods, molluscs, and small vertebrates. (Miranda and Faria, 2001)
Primary Diet:
herbivore
(eats sap or other plant foods).
Animal Foods:
insects; terrestrial non-insect arthropods; mollusks.
Plant Foods:
fruit; sap or other plant fluids.
Predation
- diurnal birds of prey (Falconiformes)
- snakes (Serpentes)
- cats (Felidae)
Black-pencilled marmosets are vulnerable to a wide range of both terrestrial and aerial predators. Aerial predators, large raptors, are considered the marmosets greatest threat, but they are also preyed upon by a variety of snakes and wild cats. Black-pencilled marmosets use a series of predator-specific vocalizations as well as visual scanning in their antipredation strategies. (Barros, Alencar, and Tomaz, 2004)
Ecosystem Roles
Black-pencilled marmosets are mutualists with many tree species, dispersing seeds of the fruit that they consume. They also act as parasites of other species of trees because they create sores in the trees in order to extract sap, while not positively affecting the tree in any way. They also serve as a source of prey for many larger animal species that reside in the forests, including large birds of prey, snakes, and wild cats. (Barros, Alencar, and Tomaz, 2004; de Figueiredo and Longatti, 1997; Lacher et al., 1981)
Key ways these animals impact their ecosystem:
disperses seeds.
- trees
- Fruit trees
Economic Importance for Humans: Negative
There are no known adverse affects of black-pencilled marmosets on humans.
Economic Importance for Humans: Positive
Black-pencilled marmosets are considered highly valuable and exotic pets. They are also used often in zoo exhibits as well as many different types of scientific studies. (Mittermeier, 1986)
Ways that people benefit from these animals:
pet trade
; research and education.
Conservation Status
IUCN Red List: [link]:
Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
Appendix II.
Black-pencilled marmosets have no special status with the IUCN Red List or the Unites States Endangered Species Act List. They are listed in Appendix II of CITES and are not currently considered an endangered or threatened species.
Contributors
Matthew Wund (editor), University of Michigan.
Valerie Ackley (author), University of Michigan. Phil Myers (editor, instructor), Museum of Zoology, University of Michigan.

