Today I’ll be talking about the first field study of one member of Pitheciidae, the titi monkey.
The first field study of titi monkeys appears to have been conducted in 1966 by William M. Mason, now a professor emeritus at the University of California. At the time, few field studies had been conducted on any South American primate; the study lasted eleven months, and took place in eastern Colombia. He focused on Callicebus moloch, the dusky titi monkey. This decision was made, in part, because Dr. Mason was interested in primate species that lived in small family groups. He completed a population census across three groves of forest, and also described the social behavior of the subjects (of which there were 28) in great detail (Mason 1966).
References
Mason W. 1966. Social organization of the South American monkey, Callicebus moloch: a preliminary report. Tulane Studies in Zoology. 13(1):24-28.
Today, I’ll focus on a particular member of the Pitheciidae family: the uakari.
There are four recognized subspecies, which can be found in Brazil, Peru, Colombia, and Venezuela (Gron 2008). Like other members of Pitheciidae, they are tropical rainforest dwellers and have a dental formula of 2:1:3:3/2:1:3:3. Specifically, they appear to prefer flooded areas that are in proximity to large water sources (Gron 2008). Primarily frugivores, they may also feed on leaves, seeds, and insects (Felton-Church 2001). It has been suggested that their distinctive red faces are the result of sexual selection (Mayor et al. 2015).
Interesting fact: the uakari monkey also has an unusually short tail. This can be seen in the above picture.
Felton-Church, A. Cacajao calvus red uakari [Internet]. U-M Ecology and Evolutionary Biology: University of Michigan; [cited 2018 Jan 16]. Available from: http://animaldiversity.org/accounts/cacajao_calvus/
Gron, KJ. Uakari Cacajao [Internet]. Primate Info Net: University of Wisconsin-Madison; [cited 2018 Jan 16]. Available from: http://pin.primate.wisc.edu/factsheets/entry/uakari
Mayor P, Mamani J, Montes D, González-Crespo C, Sebastián M, Bowler M. 2015. Proximate causes of the red face of the bald uakari monkey (Cacajao calvus). R Soc Open Sci. 2(7):150145.