Callicebus personatusmasked titi

Geographic Range

Masked titis are restricted to Atlantic coastal forests of Brazil (Nowak 1999). They live only in the southeastern Brazilian states of Bahia, Espirito Santo, Minas Gerais, Rio de Janeiro and Sao Paulo (Kinzey 1983). There are five subspecies which occupy distinct portions of this area (Wisconsin Regional Primate Research Center, 2001). Callicebus personatus is allopatric with the C. moloch and C. torquatus (Kinzey and Becker 1983).


Masked titis occur in low densities in widely scattered forests (Nowak 1999). They inhabit primary and secondary Atlantic coastal forests from sea level to 1000m (3281ft); and are also found in banana groves (Rowe 1996). They may prefer secondary forests with thick understory growth (Wisconsin Regional Primate Research Center, 2001)

  • Range elevation
    sea level to 1,000 m
    to ft

Physical Description

Masked titis are represented by 5 distinct subspecies, each with their own color patterns (Wisconsin Regional Primate Research Center, 2001). In general they have black foreheads and sideburns. Their bodies are covered with thick soft grayish to yellowish orange fur. They have a small rounded head and somewhat flattened, high face (Nowak, 1999). The nonprehensile tail is well furred and is the same color as the body, but mixed with black. Hands and feet are black (Rowe, 1996).

Body length: Female 310 – 400mm, Male 350 – 420mm; Tail Length: Female 418 – 560 mm, Male 470 – 550; Weight: Female 970 – 1600g, Male 1050 – 1650g (Rowe, 1996). Dental formula is 2/2 1/1 3/3 3/3 = 36 (Wisconsin Regional Primate Research Center, 2001). The first upper incisor has a bluntly pointed cutting edge. The second upper incisor is staggered behind the first. The molars are heavy and brachyodont with high, sharp cusps (Nowak, 1999).

  • Range mass
    970 to 1650 g
    34.19 to 58.15 oz
  • Range length
    310 to 420 mm
    12.20 to 16.54 in


Titis are monogamous and mate for life (Rowe 1996, Heiduck 1997).

Little information on reproduction in C. personatus is available. Masked titis give birth to a single offspring in August to October (Rowe, 1996; Wisconsin Regional Primate Research Center, 2001). A closely related species, C. moloch had a gestation period of 5 to 6 months. Young were weaned at 12 to 16 weeks.

  • Breeding season
    Births occur from August to October.
  • Range number of offspring
    1 to 1

Young are born helpless, they are nursed by their mothers and primarily carried by their fathers (Rowe, 1996). Males become the primary caregivers after the first week of the infants life (Wisconsin Regional Primate Research Center, 2001).

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • male
  • pre-independence
    • protecting
      • male


Longevity of C. personatus is unknown in the wild. However, a captive individual of a closely related species (C. moloch) lived to at least 25 years of age.


Masked titi monkeys are diurnal and arboreal forest dwellers (Nowak, 1999). They spend at least half of the active day resting, 2 to 3 hours feeding, and less than 20% of the day traveling (Kinzey and Becker, 1983). Their average active day, from first movement to time first individual reaches its sleeping position for the night, is 11.5 hours (Kinzey and Becker, 1983).

Titis live in family groups comprised of a male and female pair and their offspring, usually 2 to 7 individuals (Nowak, 1999). They sleep huddled, with tails entwined, in branches 25 to 40 meters high in large trees above the canopy (Kinzey and Becker, 1983; Rowe, 1996). In their usual sleeping position the body is extended and the side of their head rests in their folded hands (Nowak, 1999). Titis leave their sleeping tree at dawn and return in late afternoon (Muller et al., 1997). Adult males are usually always the last to leave the sleeping tree (Kinzey and Becker, 1983).

Normally masked titis do not descend to the forest floor. They have only been observed moving below a height of 5m during less than 1% of their daily activity period (Muller, 1997). Titis are quadrapedal. When walking on all four limbs the body hunches, rotating the hind limbs outward. The characteristic resting position is the hunched body with all four limbs brought together on the branch as the tail hangs down vertically. From the resting position, a titi monkey can jump by rapidly expanding the hind limbs while it stretches its arms outward to enable the hands to grasp another branch (Nowak, 1999).

Masked titi groups inhabit home ranges that overlap with those of other groups. They are territorial and will aggressively chase, vocalize, and display towards other groups that they encounter.

A captive masked titi used pieces of straw to pry cockroaches out of crevices. This monkey also intentionally moved his sleeping box, presumably to obtain cockroaches that had accumulated underneath it (Hill, 1960; Nowak, 1999).

Communication and Perception

Food Habits

The diet of masked titis consists mostly of fruits but also includes vegetation, small invertebrates, bird eggs, and small vertebrates (Nowak, 1999). Titis will feed on fruit from 27 different plant species but the bulk of their diet comes from only a small number of species including Manilkara paraensis (Sapotaceae) (Kinzey and Becker, 1983).

Geophagy, consumption of soil, has been observed by Masked titis. There are record accounts of Masked titis eating soil from ant mounds and less commonly from the forest floor and decomposed tree trunks (Muller et al., 1997).

Masked titis occasionally feed with Geoffroy’s Tufted-eared Marmosets (Callithrix geoffroyi) (Rowe, 1996).

  • Animal Foods
  • eggs
  • insects
  • Plant Foods
  • leaves
  • fruit


Masked titis are preyed on by large snakes, such as pit vipers and tree boas. They are also preyed on by cat species and by raptors (Muller 1997).

Ecosystem Roles

Masked titis are important in the ecosystems in which they live as prey for large predators. They may also disperse the seeds of the fruits they eat.

Economic Importance for Humans: Positive

Masked titis are an important and charismatic component of a critically endangered habitat, making them potentially valuable to ecotourism.

Economic Importance for Humans: Negative

There are no negative effects of masked titis.

Conservation Status

Masked titis are listed as vulnerable by the IUCN and are on the CITES Appendix II list (Walker, 1999). At least 95% of their habitat has been cut down for lumber and charcoal production and to make way for agriculture and pasture. Their population continues to decline as human settlement and activity encroaches into the seriously imperiled Atlantic rainforests (Nowak, 1999).


Ellen Heilhecker (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.



living in the southern part of the New World. In other words, Central and South America.

World Map


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.

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.


uses smells or other chemicals to communicate

  1. active during the day, 2. lasting for one day.

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.


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.


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.

native range

the area in which the animal is naturally found, the region in which it is endemic.


"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

seasonal breeding

breeding is confined to a particular season


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


uses touch to communicate


Living on the ground.


defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


Heiduck, S. 1997. Food choice in masked titi monkeys (*Callicebus personatus melanochir*): selectivity or opportunism?. International Journal of Primatology, 18(4): 487-502.

Kinzey, W., M. Becker. 1983. Activity pattern of the masked titi monkey, *Callicebus personatus*. Primates, 24(3): 337-343.

Muller, K., C. Alh, G. Hartmann. 1997. Geophagy in masked titi monkeys. Primates, 38(1): 69-77.

Nowak, R. 1999. Walker's primates of the world. Baltimore, MD: Johns Hopkins University Press.

Rowe, N. 1996. The pictorial guide to the living primates. New York: Pogonias Press.

Wisconsin Regional Primate Research Center, September 28, 2001. "Primate Info Net: Masked titi (*Callicebus personatus*)" (On-line). Accessed November 29, 2001 at