Department of Anthropology

Education:

Ph.D. 2005 New York University
M.A. 1999 New York University
B.A. 1989 Duke University

Areas of Research/Interest:

(PhD New York University 2005) Biological anthropology, primate behavior, ecology, conservation biology, small apes; Indonesia, Malaysia.

Background:

Dr. Lappan is a biological anthropologist and behavioral ecologist interested in the relationships among habitat characteristics, social organization, and male and female reproductive strategies. Her research primarily uses behavioral and ecological data from wild populations of nonhuman primates. Taxonomically, most of her research has been on the behavioral ecology of gibbons (family Hylobatidae), the small apes of Asia. Since 2000, she has been conducting research on wild siamangs (Symphalangus syndactylus) in the Way Canguk Research Area, Bukit Barisan Selatan National Park, Sumatra, Indonesia in collaboration with the Universitas Indonesia, the Universitas Lampung, and Wildlife Conservation Society-Indonesia Program. In 2007, she collaborated with researchers from Ewha Womans University in South Korea and the Institut Pertanian Bogor in Indonesia to initiate a research project focusing on Javan gibbons (Hylobates moloch) in the Gunung Halimun-Salak National Park, Java, Indonesia. One of the most important goals of her research is to contribute to the conservation of primates and primate habitats.

Representative Publications:

Kabir, M. T., Lappan, S., Mohd Sah, S. A., & Ruppert, N. (2025). Comprehensive surveys of endangered western hoolock gibbons (Hoolock hoolock) in Bangladesh more than double the country’s total population estimate. bioRxiv, 2025-03.

Kabir, M. T., Lappan, S., Sah, S. A. M., & Ruppert, N. (2024). Social Flexibility in Isolated Western Hoolock Gibbons (Hoolock hoolock): Temporary Partner Separation and Interspecies Association with Phayre’s Langurs (Trachypithecus phayrei). Primate Conservation, 38, 139-149.

Kabir, M. T., Lappan, S., Acharjee, R., Pomy, J. S., Sah, S. A. M., & Ruppert, N. (2024). Helminthic parasite infections of endangered western hoolock gibbons (Hoolock hoolock) in degraded habitats of Bangladesh. bioRxiv, 2024-10.

Lappan, S., Oktaviani, R., Choi, A., Ham, S., Jang, H., Kim, S., ... & Fan, P. F. (2023). Demography of a stable gibbon population in high-elevation forest on Java. Gibbon conservation in the anthropocene, 78-103.

Lappan, S., Sibarani, M., O’Brien, T. G., Nurcahyo, A., Andayani, N., Rustiati, E. L., ... & Morino, L. (2021). Long‐term effects of forest fire on habitat use by siamangs in Southern Sumatra. Animal Conservation, 24(3), 355-366.

Lappan, S., Malaivijitnond, S., Radhakrishna, S., Riley, E. P., & Ruppert, N. (2020). The human–primate interface in the New Normal: Challenges and opportunities for primatologists in the COVID‐19 era and beyond. American Journal of Primatology, 82(8), e23176.

Lappan, S., Andayani, N., Kinnaird, M. F., Morino, L., Nurcahyo, A., & O'Brien, T. G. (2017). Social polyandry among siamangs: the role of habitat quality. Animal Behaviour, 133, 145-152.

Lappan, S., Morino, L. (2014). Mating in the presence of a competitor: audience effects may promote male social tolerance in polyandrous siamang (Symphalangus syndactylus) groups. Behaviour. 151: 1067-89.

Kim, S., Lappan, S., Choe, J. C. (2012). Responses of Javan gibbon (Hylobates moloch) groups in submontane forest to monthly variation in food availability: evidence for variation on a fine spatial scale. American Journal of Primatology. 74: 1154-67.

Kim, S., Lappan, S., Choe, J. C. (2011). Diet and ranging behavior of the endangered Javan gibbon (Hylobates moloch) in a submontane tropical rainforest. American Journal of Primatology.73: 270-280

Lappan, S. (2009). Flowers are an important food for small apes in southern Sumatra. American Journal of Primatology. 71: 624-35.

Lappan, S. (2008). Male care of infants in a siamang (Symphalangus syndactylus) population including socially monogamous and polyandrous groups. Behavioral Ecology and Sociobiology. 62: 1307-17.

Lappan, S. (2007). Patterns of dispersal in Sumatran siamangs (Symphalangus syndactylus): preliminary mtDNA evidence suggests more frequent male than female dispersal to adjacent groups. American Journal of Primatology. 69: 692-98.

Lappan, S. and Whittaker, D., editors. (2009) The Gibbons: New Perspectives on Small Ape Socioecology and Population Biology. New York: Springer.