Bucknell houses four species of primates that are available for instructional purposes in several undergraduate and graduate courses as well as for research on social behavior and cognitive abilities. Students have the opportunity to observe the naturalistic behavior of the primates and, in some cases, aid in noninvasive behavioral experiments. These courses include General Psychology, Animal Behavior, Research Methods in Animal Behavior, Primate Behavior and Ecology, Animal Behavior Research, Senior Thesis, Graduate Research, Graduate Thesis, and other courses.

Lion-Tailed Macaque (Macaca silenus)

Lion-Tailed Macaque Lion-Tailed Macaque 

The Bucknell macaque colony consists of three adult males that are housed in an indoor/outdoor enclosure at the animal behavior lab. This group was established in 2002 and is on loan from the San Diego Zoo in California. 

General Research Topics:

The macaques are involved mostly in studies of nonhuman primate cognitive ability. Using touchscreen computers, the macaques have recently been involved in studies of numerical ability, picture recognition and reversal learning. An ID sketch used for distinguishing similar individuals by Katie Larkin.

Representative Publication:

Judge, P.G., Kurdziel, L.B., Wright, R.M., & Bohrman, J.A. (2012). Picture recognition of food by macaques (Macaca silenus). Animal Cognition, 15(3), 313-325..

Hamadryas Baboons (Papio Hamadryas)


The Bucknell hamadryas baboon colony consists of one adult male, several adult females and their offspring. Ages range from less than a year to over 20 years old. All adult females in the colony and their offspring are descendants from original group members purchased from Primate Imports in Port Washington, N.Y., in 1968. The adult male was acquired from the Mannheimer Foundation in Homestead, Fla., in 1996. 

Principal Investigators: Peter Judge and Regina Paxton Gazes

General Research Topics:

Most studies of the baboons involve behavioral observations of their social interactions in order to learn the complexity of their behavior. Of particular interest are the interactions that occur immediately after aggressive conflicts. Animals tend to reconcile with one another following conflicts in order to preserve preferred relationships and/or prevent future conflicts. Recent work observing the behavior of bystanders following conflicts indicates that they, too, are affected by fights between their group mates and are involved in the conflict resolution process. 

Representative Publication:

Judge, P.G., & Bachman, K.A. (2013). Witnessing reconciliation reduces arousal of bystanders in a baboon group (Papio hamadryas hamadryas). Animal Behaviour, 85(5), 881-889.

Brown Capuchin (Cebus apella)


A social group of capuchin monkeys contains two adult males, several adult females and their infant offspring. The group was established in 2000 from six individuals acquired from the Yerkes National Primate Research Center in Atlanta.

General Research Topics: 

Capuchins are highly intelligent primates and, as such, are involved in several tests of the limits of their cognitive abilities. Researchers at Bucknell have used their ability to operate a touchscreen computer to test their numerical competence and their picture-recognition abilities. As capuchins are versatile tool users, researchers have conducted several studies of tool-use ability. Most recently, researchers determined that the capuchins are capable of selecting the appropriate tool for a particular tool-use task.

Recent work has investigated their cooperative behavior and shown that two capuchins will work together so that both receive a reward.  Several capuchins have learned to barter with an experimenter. Researchers also found that the capuchins will attribute value to inanimate objects such as tokens and barter to trade for more valued items. Such behavior indicates a degree of self-control and planning, which is a necessary component of advanced social cognition. 

Representative Publication:

Judge, P.G., & Bruno, S. . (2012). Transport of functionally appropriate tools by capuchin monkeys (Cebus apella). American Journal of Primatology, 74(3), 199-209.

Squirrel Monkey (Saimiri sciureus)

Squirrel Monkey -- Saimiri Sciureus

The squirrel monkey colony is a social group of two adult males and several females living in an indoor-outdoor enclosure at the animal behavior laboratory. The group was donated to Bucknell by Stanford University in 2008. 

General Research Topics:

Bucknell researchers study post-conflict reconciliation behavior in the squirrel monkeys as a cross-species comparison to baboons. Recent work has also included investigation of their tool-use ability. The squirrel monkeys are currently being trained on a touchscreen apparatus to test their cognitive abilities.

Representative Publication:

Zander, S.L., Weiss, D.J., & Judge, P.G. (2013). The interface between morphology and action planning: A comparison of two species of New World monkeys. Animal Behaviour, 86(6), 1251-1258.