Hoolock gibbons (Hoolock sp.)

The hoolock gibbons are currently classified as two species: the endangered western hoolock gibbon and the vulnerable eastern hoolock gibbon. Most studies have described the western populations in Assam, India. Like all hylobatids, the hoolock gibbons are territorial.


The following dataset comprise data on the demography, life history, ontogeny, morphology, energetics, and nutrition of the western hoolock gibbon (Hoolock hoolock) and the eastern hoolock gibbon (Hoolock leuconedys). All data describe adults unless noted otherwise. The data are compiled from many different sources, thus compromising the value of both inter- and intraspecific data comparisons. All datasets include a sources sheet; the complete bibliography is also presented on the webpage. Many ape species have not been studied thoroughly and lack data in most areas of interest.

Whole dataset


Brockelman, W. & Geissmann, T. (2008). Hoolock leuconedys. The IUCN Red List of Threatened Species. Version 2015.2. Accessed July 2015. [link]

Brockelman, W., Molur, S. & Geissmann, T. (2008). Hoolock hoolock. The IUCN Red List of Threatened Species. Version 2015.2. [link]

Brockelman, W., Naing, H., Saw, C., Moe, A., Linn, Z., Moe, T., & Win, Z. (2009). Census of eastern hoolock gibbons (Hoolock leuconedys) in Mahamyaing Wildlife Sanctuary, Sagaing Division, Myanmar. In The Gibbons, eds. S. Lappan and D. Whittaker, pp. 435–451. Springer Science+Business Media. [link]

Das, J., Biswas, J., Bhattacherjee, P., & Mohnot, S. (2009). The distribution and abundance of hoolock gibbons in India. In The Gibbons, eds. S. Lappan and D. Whittaker, pp. 409–433. Springer Science+Business Media. [link]

Elder, A. (2009) Hylobatid diets revisited: The importance of body mass, fruit availability, and interspecific competition. In The Gibbons, eds. S. Lappan and D. Whittaker, pp. 133-159. Springer Science+Business Media. [link]

Fan, P., Bartlett, T., Fei, H. & Ma, C. (2015). Understanding stable bi-female grouping in gibbons: feeding competition and reproductive success. Frontiers in Zoology 12, 1-14. [link]

Geissmann, T. (1991). Reassessment of age of sexual maturity in gibbons (Hylobates spp.). American Journal of Primatology 23, 11–22. [link] [pdf]

Geissmann, T. & Anzenberger, G. (2009). Hormonal correlates of the ovarian cycle in the yellow-cheeked crested gibbon (Nomascus gabriellae), and a review of ovarian cycles in gibbons (Hylobatidae). Gibbon Journal 5, 61–73. [link] [pdf]

Geissmann, T. & Orgeldinger, M. (1995). Neonatal weight in gibbons (Hylobates spp.). American Journal of Primatology 37, 179–189. [link] [pdf]

Hayssen, V. & Tienhoven, A. (1993). Asdell’s Patterns of Mammalian Reproduction. Cornell University Press. [link]

International Resources Group. (2006). Management Plans for Lawachara National Park. United States Agency for International Development. [pdf]

Islam, M., Choudhury, P. & Bhattacharjee, P. (2013). Survey and census of hoolock gibbon (Hoolock hoolock) in the inner-line reserve forest and the adjoining areas of Cachar District, Assam, India. Folia Primatologica 84, 170–179.[link]

Leigh, S. R. & Shea, B. T. (1995). Ontogeny and the evolution of adult body size dimorphism in apes. American Journal of Primatology 36, 37–60. [link]

Malone, N. & Fuentes, A. (2009). The ecology and evolution of hylobatid communities: causal and contextual factors underlying inter- and intraspecific variation. In The Gibbons, eds. S. Lappan and D. Whittaker, pp. 241-264. Springer Science+Business Media. [link]

Rowe, N. (1996). The Pictorial Guide to the Living Primates. Pogonias Press. [link]