Varying ecological quality influences the probability of polyandry in white-handed gibbons (Hylobates lar) in Thailand
Journal article
Authors/Editors
Strategic Research Themes
No matching items found.
Publication Details
Author list: Savini T., Boesch C., Reichard U.H.
Publisher: Wiley
Publication year: 2009
Journal: Biotropica (0006-3606)
Volume number: 41
Issue number: 4
Start page: 503
End page: 513
Number of pages: 11
ISSN: 0006-3606
eISSN: 1744-7429
Languages: English-Great Britain (EN-GB)
View in Web of Science | View on publisher site | View citing articles in Web of Science
Abstract
Although members of the family Hylobatidae are known to be monogamous, adult white-handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand, also show multimale groups and polyandry. A need for more than one male to successfully raise offspring cannot explain the occurrence of polyandry in these territorial primates, because direct paternal care is absent in this species. We hypothesize that polyandry is primarily related to costs/benefits for males of cooperatively defending a female and/or resources; our prediction was that polyandry would become more frequent with increasing costs of female/resource defense. We measured the ecological quality of seven gibbon home ranges over a 3-yr period (2001-2003) to investigate how resource availability affected the probability of polyandry, and found a significant negative relationship between home range quality and home range size. Larger home ranges were of lower quality. As predicted, groups living on larger, poorer home ranges also experienced longer periods of polyandry. In forest areas of comparatively low quality, acquiring and maintaining a large home range that includes enough resources for a female to reproduce steadily may surpass a single male's capacity. Our model of cooperative male polyandry was supported by preliminary data of shared territorial defense and access to the female. However, interaction proportions were strongly skewed, and female's primary male partners monopolized grooming and mating. Nevertheless, a primary male on a large territory may benefit from the presence of a secondary male with aid in territorial/female defense, whereas a secondary male may gain by avoiding high dispersal costs. ฉ 2009 by The Association for Tropical Biology and Conservation.
Keywords
Home range quality, Monogamy, Multimale groups