Behavioral Ecology and Sociobiology

, Volume 42, Issue 5, pp 329–339 | Cite as

Dispersal, pair formation and social structure in gibbons (Hylobates lar)

  • Warren Y. Brockelman
  • Ulrich Reichard
  • Uthai Treesucon
  • Jeremy J. Raemaekers


We report observations on reproduction, natal dispersal, pair formation, and group structure based on longitudinal observations of several white-handed gibbon (Hylobates lar) groups spanning 18 years. Our observations are at odds with the traditional view that gibbons live in nuclear family groups consisting of a pair of adults and their offspring, and that parents exclude young from the family territory when they reach adult size. In the relatively dense Khao Yai study population, dispersing young usually obtain mates by replacing adults in existing territories, which creates non-nuclear families. Six subadults, five males and one female, matured and dispersed at an average age of 10 years, or about 2 years after reaching adult size. Average natal dispersal distance was 710 m, or between one and two territories away. At least two dispersing males replaced adults in neighboring groups. In one case, forcible displacement of the resident male resulted in a group which included a young juvenile presumably fathered by the previous male, two younger juveniles (probably brothers) from the new male's original group, and (later) offspring of the new pair. Social relations within this heterogeneous group remained harmonious: the adults groomed all the young and play occurred between all preadult members. In only two out of a total of seven cases of dispersal seen did two subadults pair and disperse into new territorial space. Nonreproducing subadults which delay dispersal may be tolerated by the adults provided that they contribute benefits to the adults or their offspring. Possible benefits include behaviors such as grooming, social play with juveniles, and support of the adult male in defending the territory. Delayed dispersal is probably advantageous in a saturated environment where there is no room for floaters, but subadults may also gain indirect fitness benefits by aiding siblings and other relatives.

Key words Gibbon Pair formation Hylobates lar Social structure Natal dispersal 

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Warren Y. Brockelman
    • 1
  • Ulrich Reichard
    • 3
  • Uthai Treesucon
    • 2
  • Jeremy J. Raemaekers
    • 4
  1. 1.Biology, Faculty of Science, Mahidol University, Salaya, Buddhamonthon, Nahkon Pathom 73170, Thailand e-mail:, Fax: 662-441-1013TH
  2. 2.Center for Conservation Biology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, ThailandTH
  3. 3.Institut für Anthropologie der Georg-August-Universität, D-37073 Göttingen, GermanyDE
  4. 4.School of Planning and Housing, Edinburgh School of Art, Lauriston Place, Edinburgh EH3 9DF, UKGB

Personalised recommendations