Thad Bartlett, Ph.D.

Department Chair, Anthropology

Thad Bartlett


My primary research interest is in the behavioral ecology of living primates. Behavioral ecology focuses on how individuals adapt to constraints imposed by physical and social environments. To be successful in an evolutionary sense, animals have to cope, minimally, with three problems: finding food, avoiding predators, and finding reproductive partners. Solutions to these problems will differ under differing ecological conditions and one goal of primatology is to document patterns of response across species in order to better understand the principles that guide primate adaptation and evolution. Under the umbrella of primate behavioral ecology, I have focused in particular on the role of food availability in shaping primate behavior and social structure. My exploration of this topic has taken two very different tracks, first, through the study of foraging behavior and resource competition in wild primates and, second, through controlled studies of maternal undernutrition and progeny outcomes in captive baboons. More recently, I have begun to focus on the ecology and behavior of primates in anthropogenic habitats.

Research Interests

  • Hylobatidae
  • Socioecology 
  • Territoriality
  • Sexual Selection
  • Foraging Behavior and Resource Competition
  • Maternal Under-Nutrition and Progeny Outcomes


  •  Ph.D. in Anthropology, Washington University (1999) 
  • M.A. in Anthropology, Washington University (1992)
  • B.A. in Anthropology, Grinnell College (1988)


2022 - Bartlett TQ and Sussman RW. Gibbons: arboreal acrobats of southeast Asia. In: The Natural History of Primates: A Systematic Survey of Ecology and Behavior, RW Sussman, D Hart, and IC Colquhoun (eds.). Rowman & Littlefield Publishers, pp. 535-556.

2022 - Bartlett TQ and Sheldon AC. Gibbon evolved sexual psychology. In: The Cambridge Handbook of Evolutionary Perspectives on Sexual Psychology, TK Shackelford (ed.). Oxford University Press. Doi:10.1017/9781108943581.021

2022 - Pang YH, Lappan S, Bartlett TQ, Mohd Sah SAN, Nik Rosely NF and Ruppert N. Population densities of Hylobates agilis in forests with different disturbance histories in Ulu Muda Forest Reserve, Malaysia. American Journal of Primatology, e23388.

2021 - Light LEO, Savini T, Sparks C, and Bartlett TQ. White-handed gibbons (Hylobates lar) alter ranging patterns in response to habitat type. Primates 62:77-90.

2020 - Mohd Rameli NIA, Lappan S, Bartlett TQ, Ahmad SK, Ruppert N. Are social media reports useful for assessing small ape occurrence? A pilot study from Peninsular Malaysia. American Journal of Primatology. 2020;e23112.

2019 - Ma CY, Brockelman WY, Light LEO, Bartlett TQ, and Fan PF. Infant loss during and after male replacement in gibbons. American Journal of Primatology 81:e23036.

2016 - Bartlett TQ, Light LEO and Brockelman WY. Long-term home range use in white-handed gibbons (Hylobates lar) in Khao Yai National Park. American Journal of Primatology. 78(2):192-203.

2011 - Bartlett TQ. The Hylobatidae: small apes of Asia. In: Primates in Perspective 2nd Edition, CJ Campbell, A Fuentes, KC MacKinnon, RM Stumpf and SK Bearder (eds). Oxford University Press, pp. 300-312.

2009 - Bartlett, Thad Q. The Gibbons of Khao Yai: Seasonal Variation in Behavior and Ecology. Upper Saddle River, NJ: Pearson Prentice Hall.

2009 - Bartlett, Thad Q. Seasonal Home Range Use and Defendability in White-Handed Gibbons (Hylobates lar) in Khao Yai National Park, Thailand. In The Gibbons: New Perspectives on Small Ape Socioecology and Population Biology. Edited by Lappan, S. M., Whittaker, D. and Geissmann, T. Pp. 265-275. Berlin: Springer.

2003 - Bartlett, Thad Q. Intragroup and Intergroup Social Interactions in Hylobates lar. International Journal of Primatology 24(2): 239-259.