Masked Titi (Callicebus personatus)

The average body mass for the adult male is 1.27 kilograms and for the adult female it is 1.38 kilograms (Hershkovitz, 1990). The canines are sexually monomorphic for this species (Kinzey, 1972). The dental formula is 2:1:3:3 on both the upper and lower jaws (Ankel-Simons, 2000).

This species has five subspecies, each having their own pelage coloration:

The masked titi is found in the country of Brazil. This species lives on the East coast in the Atlantic coastal rainforests. This species lives in secondary forests, but not primary forests (Stallings and Robinson, 1991). This species has been observed in banana tree groves (Kinzey, 1981).

This species has five subspecies each having their own range:

The masked titi is primarily a frugivorous species, but also eats leaves and insects. In the state of Bahia, Brazil, it was found that the main food source of the subspecies Callicebus personatus melanochir was Vochysia rudeliana (Heiduck et al., 1996). It was found in Sooretama Biological Reserve, Espirito Santo, Brazil that this species spent 81% of the time feeding on fruit of 27 different species with the species Manilkara paraensis comprising the most common fruit species consumed (41%) (Kinzey and Becker, 1983). The rest of the feeding time was devoted to leaves (18%) and three species of flowers (Kinzey and Becker, 1983). Secondary forests may be more favorable for this species because they contain a higher production of fruit and palatable leaves (Stallings and Robinson, 1991). Heiduck (1997) describes this species as an opportunistic feeder. Leaves from lianas are consumed with most of the leaves immature (98%) rather than mature (2%) (Muller, 1996). At the Lemos Maia Experimental Station, Bahia, Brazil the subspecies Callicebus personatus melanochir was found to feed on fruit 85.2% of the time, leaves 14.1% of the time, and flowers and insects 0.7% of the time (Heiduck, 1997). Most of the leaves consumed were young leaves (90%) as opposed to mature (10%) ones (Heiduck, 1997). Of the fruits eaten 51.6% of the fruit part consumed were the fleshy fruit parts and 26.4% were the seeds (Heiduck, 1997). During the dry season the subspecies Callicebus personatus melanochir will consume more seeds in the diet (Heiduck, 1997). Also during the dry season groups will utilize fewer food source patches than in the wet season, and groups will also travel less during the dry season (Heiduck, 1998). During the warmer months, the masked titi will consume more fruits than colder months (Muller, 1996). At the Lemos Maia Experimental Station, Muller (1996) found that the two most important species consumed were Manilkara longifolia and Sprucella crassipedicellata.

This species is diurnal and arboreal and rarely comes to the forest floor (Kinzey, 1997). The masked titi occurs in the lower levels of the forest canopy in thickets and vine tangles (Stallings and Robinson, 1991). Average group size for this species was found to be 3.9 individuals (Pinto et al., 1993). Daily activity begins for this species with the individuals moving from their sleeping position on a tree bough where they were huddled and had their tails entwined with other group members (Kinzey and Becker, 1983). The last individual to leave the sleeping position is usually the adult male (Kinzey and Becker, 1983). Before moving from the sleeping tree, group members will urinate and defecate (Kinzey and Becker, 1983). Before leaving the sleeping tree, adult males and females may engage in a duet and give a dawn call, and other groups may be heard to respond to this call (Kinzey and Becker, 1983). After leaving the sleeping tree that group will move to a fruit tree to feed and throughout the day the group will alternate feeding and resting (Kinzey and Becker, 1983). During an active period of an average of 11.5 hours during the day, this species spent 6.4 hours resting, 2.1 hours feeding, and 1.5 hours traveling (Kinzey and Becker, 1983). The masked titi was found to show two different activity patterns during the day (Kinzey and Becker, 1983). The first pattern consisted of two feeding peaks with a long rest period in between and rapid travel between feeding sites (Kinzey and Becker, 1983). The second pattern consists of three feeding peaks with rest periods in between, but there is relatively little travel (Kinzey and Becker, 1983). The home range for this species tends to be smaller during the dry months of the year (Muller, 1995). During the warm season the masked titi will rest longer during the day (Muller, 1996). This species will sleep in a large bough of a tree, with the bough being of an average height of 32 meters (Kinzey and Becker, 1983).

The masked titi moves through the understory of the forest quadrupedally as well as by leaping (Fleagle, 1988). This species often uses vertical clinging when feeding (Fleagle, 1988).

The masked titi has a monogamous mating system and mates for life. A dominance hierarchy does not seem to exist (Kinzey, 1997). The basic group is composed of the breeding pair and their offspring. Grooming is an important activity that serves to strengthen social bonds amongst members of the group. The males participate in caring for the infants, becoming the main caregiver after the first week of life of the infant. This species, like members of its genus, are highly territorial (Kinzey, 1997). Pairs of masked titis have been known to engage in duets with other pairs at dawn (Fleagle, 1988).

loud call: This call is composed of a series of short sequences of noises that sound like "chirrup-pump". This call can be given in either a single burst or a series of short bursts each last a few seconds to two minutes (Flesher, 1999). This call is given by males as a territorial call and can be heard for up to one kilometer.



tail-entwining: This is used to reinforce bonds amongst pairs. This is where two individuals are sitting and have their tails wrapped around each others.

The masked titi gives birth to a single offspring. The birth season is from August to October (Kinzey, 1981).

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Last Updated: October 5, 2003.
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