Ryne A. Palombit


Research Interests    Teaching & Courses
Publications Graduate Students

© Ryne A. Palombit     © Ryne A. Palombit  

"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: (848) 932-9275
FAX: (732) 932-1564

Director, Center for Human Evolutionary Studies (CHES)

Director, Primatology, Wildlife Ecology, and Conservation field school.

Email: rpalombit@anthropology.rutgers.edu

Office: 001 Biological Sciences Building, Douglass Campus

Office Hours Fall 2015 Semester: Monday 4:00 - 5:00 pm, Thursday 2:30 -3:30 pm

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. Anthony di Fiore (Anthropology, New York University) for genetic analyses, and Dr. Dorothy Cheney (Biology, University of Pennsylvania) and Dr. Robert Seyfarth (Psychology, University of Pennsylvania) for the Botswama component.  My research has been 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 (Nairobi, Kenya).

PhD Graduate Student Advisees:

• Marc Shur obtained his PhD in 2008: The Socioendocrinology of "Friendship" Between Adult Male and  Lactating Female Baboons, funded by the L.S.B. Leakey Foundation, the Wenner-Gren Foundation, and a Fulbright IIE Fellowship.  Dr. Shur is currently Chair of the Mathematics and Science Department at Berkeley College, New York City, New York.

• Luca Morino obtained his PhD in 2012:  Behavioral Endocrinology of Wild Male Siamangs (Symphalangus syndactylus).  This research was funded by the National Science Foundation and the Wenner-Gren Foundation.

• Nancy Moinde obtained her PhD in 2015: The Effects of Land Use Systems on the Socioecology of the Olive Baboon (Papio hamadryas anubis) and the Human-Baboon Interactions in Laikipia District, Kenya, based on research she completed at my field site in Kenya.  This research was funded by the National Science Foundation, Wenner-Gren Foundation, and the L.S.B. Leakey Foundation.   Dr. Moinde is currently Research Scientist at the Institute of Primate Research, Nairobi, Kenya.

• Emily Lynch obtained her PhD in 2016:  Paternal Kinship in a Matrilocal Society of Olive Baboons (Papio hamadryas anubis) in Laikipia District, Kenya. This research was funded by the National Science Foundation, the L.S.B. Leakey Foundation, and a Fulbright IIE Fellowship.

• Stan Kivai (M.Sc. in Biology, Addis Ababa University) has advanced to candidacy in the PhD program and is currently conducting his dissertation field research, The Influence of Mechincal and Nutritional Properties of Foods on Feeding in Wild Juvenile Tana River Mangabeys, Cercocebus galeritus, in Lower Tana River Forests, Kenya. This research is being funded by the L.S.B. Leakey Foundation, Conservation International, Primate Conservation Inc., the Palaeontological Trust, and the International Society of Primatoloigsts.

• Alex Pritchard (M.Sc. Primate Behavior, Central Washington University)
entered our PhD program in the Fall of 2013.  He is currently completing his dissertation research proposal to study personality and cognition in olive baboons, based upon pilot research he conducted at my Kenyan field site.

• Melanie Jackson (B.S. Evolutionary Anthropology, University of Michigan) entered the PhD program in the Fall of 2014.   Based upon last summer's pilot research at my fieldsite, she is currently developing a dissertation topic investigating the tradeoffs of coercive versus affinitive mating strategies in male in olive baboons.

Other Graduate Students Conducting Research at My Fieldsite:

• Caley Johnson (Hunter College, New York City), has collected behavioral data on feeding and nutritional data on baboon foods as part of her dissertation research Baboon Diet in the Forest and Savannah: An Intraspecific Comparison of Nutritional Goals.

• Lisa Danish 2013, PhD dissertation: “Following,” An Alternative Mating Strategy of Male Olive Baboons (Papio hamadryas anubis.

Postdoctoral Research Associates:

• Akiko Matsumoto-Oda (PhD, Kyoto University) studied the relationship between "friendships" and male-infant bonds among olive baboons in Kenya.  She is currently on the faculty of Ryukyus University.

• Alban Lemasson (PhD, University of Rennes) is studied vocal communication in the context of heterosexual "friendships" in olive baboons.  He is currently on the faculty of the University of Rennes.

Teaching Interests
(courses taught)

Undergraduate Courses:

Life of Primates (Anthro 212)

Primate Behavioral Ecology (Anthro 348)
Primatology & Human Evolution (Anthro 350)
Primate Cognition (Anthro 402)

Graduate Seminars:

Biology of Social Bonds (Anthro 563)
Primate Ecology & Social Behavior (Anthro 568)
Sex Differences & Sexual Selection in Primates (Anthro 569)
Methods in Field Primatology  (Anthro 574)

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)



Mitani, J.C., Call, J.P., Kappeler, P.M., Palombit, R.A., & Silk, J.B.  (editors).  2012.  Evolution of Primate Societies.  Chicago University Press, Chicago.

Selected Publications

Palombit, R.A.  in press.  Infanticide.  In: Encyclopedia of Human Sexuality (P. Whelehan & A. Bolin, eds.), Wiley-Blackwell, New York.

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

Matsumoto-Oda, A. & Palombit, R.A.  in press. Activity budgets and rainfall seasonality in a wild savanna baboon (Papio anubis) group.  Primate Research.

Palombit, R.A.   in press.  "Friendship" in primates.   In: International Encylopedia of Primatology (Fuentes, A., ed.)  Wiley-Blackwell.

Palombit, R.A.   in press.  Genus Papio.   In: International Encylopedia of Primatology (Fuentes, A., ed.)  Wiley-Blackwell.

with Wich, S.A & Sterck, E.M.   in press.  Ketambe research station.   In: International Encylopedia of Primatology (Fuentes, A., ed.)  Wiley-Blackwell.

Lynch, E.C, di Fiore, A.T., & Palombit, R.A.  2015.   Fathers mediate social bonds among young offspring in olive baboons (Papio hamadryas anubis).   American Journal of Primatology,

Palombit, R.A.  2014.  Sexual conflict in nonhuman primates.  Advances in the Study of Behavior, 46:191-280. [pdf]

Palombit, R.A.  2014.  The sexual conflict of infanticide.   In: Genetics and Biology of Sexual Conflict (W.R. Rice & S. Gavrilets, eds.), pp. 199-227.  Cold Spring Harbor Press, New York. [pdf]

Danish, L.M. & Palombit, R.A.  2014.  “Following,” an alternative mating strategy used by male olive baboons (Papio hamadryas anubis): Quantitative behavioral and functional description.  International Journal of Primatology,  35:394-410. [pdf]

Palombit. R.A.  2013.  Papio anubis — olive baboon.  In: Mammals of Africa. Vol. II. Primates. (T.M. Butynski, J. Kingdon, & J. Kalina, eds), pp. 233-239, Bloomsbury, London.

Danish, L.M., di Fiore, A.T., & Palombit, R.A.  2013.  “Following” in olive baboons (Papio hamadryas anubis) results in deviation from the Priority of Access Model: Consortship behavior and genetic paternity.   American Journal of Physical Anthropology, 150:107.

Palombit, R.A.  2012.   Infanticide: Male strategies and female counterstrategies.  In: Evolution of Primat Societies (J.C. Mitani, J.P. Call, P.M. Kappeler, R.A. Palombit, J.B. Silk, eds.), pp. 432-468.  Chicago University Press.  Chicago.

Danish, L.M, & Palombit, R.A.  2012.  “Following,” an alternative mating strategy used by male olive baboons (Papio hamadryas anubis): Description and outcomes.  American Journal of Physical Anthropology, 147:125.

Danish, L.M. & Palombit, R.A.  2011.  Factors influencing the expression of “following,” an alternative mating strategy in male olive baboons in Kenya.  American Journal of Primatology, 73:72.
Palombit, R.A.  2010.  Conflict (and bonding) between the sexes.  In: Mind the Gap—Tracing the Origins of Human Universals (P.M. Kappeler & J.B. Silk, editors), pp. 53-84.  Springer, Berlin. [pdf]

Palombit, R.A. 2009.  Friendships with males: A female counterstrategy to infanticide in the Okavango chacma baboons.  In: Sexual Coercion in Primates and Humans: An Evolutionary Perspective On Male Aggression Against Females, (M.N. Muller & R.W. Wrangham, eds.), pp. 377-409.  Harvard University Press, Cambridge, Massachusetts. [pdf, 532KB]

Danish, L.M. & Palombit, R.A.   2008.  What distinguishes “follower” males from non-follower males in olive baboons (Papio hamadryas baboons)?  American Journal of Primatology, 70S:60.

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, Detroit, Michigan.

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.

Shur, M.D., Palombit, R.A. & Whitten, P.L.  2008.  Protection from male versus female harassment: Association between glucocorticoid concentrations and friendship in wild lactating olive baboons (Papio hamadryas anubis) in Laikipia, Kenya.  American Journal of Primatology, 70 (S1):28.

Shur, M.D., Palombit, R.A. & Whitten, P.L.  2008.  Association between male testosterone and friendship formation with lactating females in wild olive baboons (Papio hamadryas anubis).  American Journal of Physical Anthropology, 135(S46):193.

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. Leigh, 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.  [pdf]

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]

© R.A. Palombit

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

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