Ryne A. Palombit's Homepage

Ryne A. Palombit

Simian Seminar PrimateGroupS07

To see interview about this research as it pertains to recent PBS Nature® documentary "Murder in the Troop" click: Interview

"Friendships" in chacma baboons of the Okavango Delta, Botswana (left) & olive baboons of Laikipia, central Kenya (right)

Department of Anthropology

131 George Street

Rutgers University

New Brunswick, New Jersey 08901-1414

Phone: (732) 932-5214

FAX: (732) 932-1564

Email: palombit@rci.rutgers.edu

Office: 001 Biological Sciences Building, Douglass Campus

Office Hours: Monday, 10:30-11:30am & 4:30-5:30 pm (Spring 2008)

Research Interests

I am interested in understanding how the extraordinary diversity of social and mating strategies in animals (both human and nonhuman) has evolved. My current interests focus on a feature of primate biology that largely differentiates these animals from most other mammals: cohesive social bonds between adult males and females persisting beyond estrus. I use the comparative approach and field experiments to understand the behavioral and ecological bases of variation in male-female social relationships. I have studied monogamous pair bonds in wild white-handed gibbons (Hylobates lar) and siamang (H.syndactylus) in northern Sumatra, Indonesia, and conducted short-term research on titi monkeys (Callicebus moloch) and red-bearded saki monkeys (Pithecia aequatorialis) in the upper Amazon of Ecuador. Currently, I direct "Project Papio, a study "friendships" in chacma baboons in Okavango Delta, Botswana and in olive baboons at my field site in Laikipia, Kenya (photos above).

PROJECT PAPIO: Comparative Study of Infanticide and Anti-Infanticide Strategies in Baboons

I am currently conducting a long-term comparative study of chacma baboons (Papio hamadryas ursinus) in Botswana and olive baboons (Papio hamadryas anubis) in central Kenya. The aim is to understand the evolution of male infanticide and female counter-strategies to infanticide. Of particular interest are the affiliative bonds between males and lactating females, known as "friendships." Our data suggest that this social relationship functions as a deterrent to sexually selected infanticide in chacma baboons, which accounts for at least 37% of infant mortality. In East African olive baboons, however, male infanticide occurs rarely, and yet heterosexual friendships develop just as reliably. This difference is just one of numerous social features distinguishing chacma baboons from their East African cousins (e.g., lack of male-male coalitions, apparently greater sexual monopolization of estrus females by high-ranking males, enhanced territoriality). I am studying variation within and between both populations of baboons, collecting genetic, experimental, and observational data that will clarify the causal and functional bases of sexually selected infanticide and heterosexual bonds in a multi-male social setting.

Collaborators in this project include Dr. Dorothy Cheney (Biology, University of Pennsylvania) and Dr. Robert Seyfarth (Psychology, University of Pennsylvania) for the Botswama component, and Dr. Clifford Jolly (Anthropology, New York University) and Dr. Tim Newman (National Institutes of Health) who are conducting genetic analyses. My research is supported by grants from the National Science Foundation, the L.S.B. Leakey Foundation, the Wenner-Gren Foundation, the Center for Human Evolutionary Studies, and Rutgers University. The research is sponsored by the National Museums of Kenya and the Institute of Primate Research.

Postdoctoral Research Associates:

• Akiko Matsumoto-Oda (PhD, Kyoto University) is studying the relationship between "friendships" and male-infant bonds among olive baboons in Kenya.

• Alban Lemasson (PhD, University of Rennes) is studying vocal communication in the context of heterosexual "friendships" also in olive baboons.

PhD Graduate Students:

• Marc Shur (M.A., California State University, Fullerton) is currently studying the hormonal bases of male-female "friendships" in olive baboons at my fieldsite in Kenya

• Luca Morino (M.Sc., University of Florence) has conducted long-term research of wild white-handed gibbons in Thailand, and is currently working on a study of monogamy in wild Indonesian siamang

• Nancy Moinde (M.Sc., University of Cape Town) has studied Kenyan primates and will study ecological & conservation aspects of baboon-human conflict in central Kenya

• Lisa Danish (B.S., University of Florida, Gainesville) has analyzed the nutritional value of foods of red colobus monkey, red-tail monkey and golden monkey of Virungas.

• Emily Aronoff (B.S. George Washington University) has studied vocal development in marmosets at the National Institutes of Health (poster presented at the meeting of the American Society of Primatologists, August 2006)

• Angela van Rooy (M.Sc., University College London) investigates the evolutionary significance of sexual swellings through observational, hormonal and experimental study of wild olive baboons at my fieldsite as well as captive olive baboons at the Institute of Primate Research (Kenya)

Teaching Interests (courses taught):

Undergraduate Courses:

Survey of the Living Primates (Anthro 212) (Course Description)

Primate Socioecology (Anthro 348) (Fall 2007 Syllabus)

Primatology & Human Evolution (Anthro 350)

Primate Cognition (Anthro 402) (Fall 2000 Syllabus)

Graduate Seminars:

Biology of Social Bonds (Anthro 563) (Fall 2006 Syllabus)

Primate Ecology & Social Behavior (Anthro 568) (Spring 2005 Syllabus)

Sex Differences & Sexual Selection in Primates (Anthro 569) (Spring 2008 Syllabus)
Methods in Field Primatology (Anthro 574) (Fall 2005 Syllabus)

Editorial Board

Primates (Editorial Advisory Board, 2003 - current)

African Primates: Journal of the Africa Section of the IUCN/SSC Primate Specialist Group (Editorial Committee)

American Journal of Primatology (Associate Editor, 1999-2004)

Selected Publications:

Mitani, J.C., Call, J.P., Kappeler, P.M., Palombit, R.A., & Silk, J.B. (editors). in prep. Evolution of Primate Societies.

Palombit, R.A. forthcoming. Sexual conflict as a universal in primate reproductive biology. In: Mind the Gap—Tracing the Origins of Human Universals (P.M. Kappeler & J.B. Silk, editors). Springer.

Palombit, R.A. in press. Friendships with males: A female counterstrategy to infanticide in the Okavango chacma baboons. In: Male Aggression Against Females in Primates, (M.N. Muller & R.W. Wrangham, eds.). Harvard University Press, Cambridge, Massachusetts.

Palombit. R.A. in press. The olive baboon (Papio anubis). In: Mammals of Africa. Vol. I. Primates. (J. Kingdon, D. Happold, & T. Butynski, eds).
Academic Press.

Palombit, R.A. in press. Olive baboon (Papio anubis). In: All the World's Primates (N. Rowe, ed). Charlestown, Rhode Island. Pogonias Press.

Lemasson, A., Palombit, R.A. & Jubin, R. 2008. Friendships between males and lactating females in wild olive baboons: Observations and call playback experiments. Behavioral Ecology & Sociobiology, 67:1027-1035. [pdf, 220KB]

Palombit, R.A. 2008. Primates. International Encylopedia of the Social Sciences, 2nd edition, (W.A. Darity, ed), vol. 6, pp. 459-462. Macmillan / Thomas Gale.

Lemasson, A., Palombit, R.A. & Jubin, R. 2007. Is friendship between adult males and lactating females a counter-strategy to infanticide? Observations and playback experiments in Kenyan olive baboons. Folia Primatologica, 78:202.

Cheney, D.L., Seyfarth, R.M., Fischer, J., Beehner, J., Bergman, T., Johnson, S.E., Kitchen, D.M., Palombit, R.A., Rendall, D. & Silk, J.B. 2006. Reproduction, mortality, and female reproductive success in chacma baboons of the Okavango Delta, Botswana. In: Reproduction and Fitness in Baboons: Behavioral, Ecological, and Life History Perspectives, (L. Swedell & S.R. Leight, eds.), pp. 147-176. Springer, New York.

Cheney, D.L., Seyfarth, R.M., Fischer, J., Beehner, J., Bergman, Johnson, S.E., Kitchen, D., Palombit, R.A., Rendall, D., and Silk, J.B. 2004. Factors affecting reproduction and mortality among baboons in the Okavango Delta, Botswana. International Journal of Primatology, 25:401-428. [pdf] [216 KB]

Palombit, R.A. 2003. Male infanticide in savanna baboons: Adaptive significance and intraspecific variation. In: Sexual Selection and Reproductive Competition in Primates: New Perspectives and Directions (C.B. Jones, ed.), pp. 367-412. American Society of Primatologists. [pdf, 884KB]

Palombit, R.A. 2003. ‘Friendship’ behavior as a reproductive strategy in savanna baboons: Intraspecific variation. American Journal of Physical Anthropology, Supplement 36:163-164.

Palombit, R.A. 2001. Why primates kill their young: Incidences of infanticide in monkey and ape species. In: The Encyclopedia of Mammals, 2nd edition (D.W. MacDonald, editor), pp. 392-393. Oxford University Press. London.

Palombit, R.A., Cheney, D.L., and Seyfarth, R.M. 2001. Female-female competition for male "friends" in wild chacma baboons (Papio cynocephalus ursinus). Animal Behaviour, 61:1159-1171. [pdf, 196 KB]

Palombit, R.A. 2000. Infanticide and the evolution of male-female bonds in animals. In: Infanticide by Males and Its Implications (C.P. van Schaik and C.R. Janson, eds.), pp. 239-268. Cambridge University Press, Cambridge. [pdf, 292 KB]

Palombit, R.A., Cheney, D.L., Fischer, J., Johnson, S., Rendall, D., Seyfarth, R.M, and Silk, J.B. 2000. Male infanticide and infant defense in chacma baboons. In: Infanticide by Males and Its Implications (C.P. van Schaik and C.R. Janson, eds.), pp. 123-152. Cambridge University Press, Cambridge. [pdf, 308 KB]

Cohen, M., Parr, L., & Palombit, R.A. 2000. Cracking the code: The contextual use of facial expressions by group-housed chimpanzees (Pan troglodytes) and human children (Homo sapiens). American Journal of Primatology, 51(S1):52.

Palombit, R.A. 1999. Infanticide and the evolution of pair bonds in nonhuman primates. Evolutionary Anthropology, 7:117-129. [pdf, 128 KB]

Palombit, R.A., Seyfarth, R.M., and Cheney, D.L. 1999. Male grunts as mediators of interaction with females in wild chacma baboons (Papio cynocephalus ursinus). Behaviour, 136:221-242. [pdf] [1.7 MB]

Wich, S.A., Steenbeek, R., Sterck, E.H.M., Palombit, R.A., and Usman, S. 1999. Tree mortality and recruitment in an Indonesian rain forest. Tropical Biodiversity, 6:189-195.

Palombit, R.A., Seyfarth, R.M., & D.L. Cheney. 1997. The adaptive value of "friendships" to female baboons: Experimental and observational evidence. Animal Behaviour, 54:599-614. [pdf] [195 KB]

Palombit, R.A. 1997. Inter- and intra-specific variation in the diets of sympatric siamang (Hylobates syndactylus) and white-handed gibbons (Hylobates lar). Folia Primatologica, 68:321-337. [pdf] [1.1 MB]

Palombit, R.A. 1997. Of neglect and negligence: Conservation, science, and the fate of the red ape. American Journal of Primatology, 42:61-65. [pdf] [40 KB]

Palombit, R.A. 1996. Pair bonds in monogamous apes: A comparison of the siamang (Hylobates syndactylus) and the white-handed gibbon (Hylobates lar). Behaviour, 133:321-356. [pdf] [2.3 MB]

Palombit, R.A. 1996. The Siamang and White-Handed Gibbon. In: Leuser: A Sumatran Sanctuary (C. P. van Schaik and J. Supriatna, eds.), pp. 269-280. Yayasan Bina Sains Hayati Indonesia, Depok, Indonesia.

Cheney, D.L., R.M. Seyfarth, & R.A. Palombit. 1996. The function and underlying mechanisms of baboon 'contact' barks. Animal Behaviour, 52:507-518. [pdf] [262 KB]

Palombit, R.A. 1995. Longitudinal patterns of reproduction in wild female siamang (Hylobates syndactylus) and white-handed gibbons (Hylobates lar). International Journal of Primatology, 16:739-760.

Palombit, R.A. 1994. Dynamic pair bonds in hylobatids: Implications regarding monogamous social systems. Behaviour, 128:65-101. [pdf] [2.4 MB]

Palombit, R.A. 1994. Extra-pair copulations in a monogamous ape. Animal Behaviour, 47:721-723. [pdf] [135 KB]

Palombit, R.A. 1993. Lethal territorial aggression in a monogamous primate. American Journal of Primatology, 31:311-318.

Grether, G.F., R.A. Palombit, and P.S. Rodman. 1992. Gibbon foraging decisions and the marginal value model. International Journal of Primatology, 13:1-18.

Palombit, R.A. 1992. A preliminary study of vocal communication in wild long-tailed macaques (Macaca fascicularis). I. Vocal repertoire and call emission. International Journal of Primatology, 13:143-182. [pdf] [3.6 MB]

Palombit, R.A. 1992. A preliminary study of vocal communication in wild long-tailed macaques (Macaca fascicularis). II. Potential of calls to regulate intragroup spacing. International Journal of Primatology, 13:183-207. [pdf] [2.2 MB]

"Pair Bond" in wild Mueller's Gibbons (Hylobates muelleri)

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