Why do orangutans leave the trees? Terrestrial behavior among wild Bornean orangutans (Pongo pygmaeus wurmbii) at Tuanan, Central Kalimantan.

Autor: Ashbury AM; Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland., Posa MR; Department of Biological Sciences, National University of Singapore, Singapore., Dunkel LP; Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland., Spillmann B; Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland., Atmoko SS; Fakultas Biologi, Universitas Nasional, Jakarta, Indonesia., van Schaik CP; Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland., van Noordwijk MA; Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland.
Jazyk: angličtina
Zdroj: American journal of primatology [Am J Primatol] 2015 Nov; Vol. 77 (11), pp. 1216-29. Date of Electronic Publication: 2015 Aug 28.
DOI: 10.1002/ajp.22460
Abstrakt: Orangutans (genus Pongo) are the largest arboreal mammals, but Bornean orangutans (P. pygmaeus spp.) also spend time on the ground. Here, we investigate ground use among orangutans using 32,000 hr of direct focal animal observations from a well-habituated wild population of Bornean orangutans (P. p. wurmbii) living in a closed-canopy swamp forest at Tuanan, Central Kalimantan, Indonesia. Ground use did not change with increasing observation time of well-habituated individuals, suggesting it was not an artifact of observer presence. Flanged males spent the most time on the ground (ca. 5% of active time), weaned immatures the least (around 1%). Females and immatures descended mainly to feed, especially on termites, whereas flanged males traveled more while on the ground. Flanged males may travel more inconspicuously, and perhaps also faster, when moving on the ground. In addition, orangutans engaged in ground-specific behavior, including drinking from and bathing in swamp pools. Supplementary records from 20 ground-level camera traps, totaling 3986 trap days, confirmed the observed age-sex biases in ground use at Tuanan. We conclude that ground use is a natural part of the Bornean orangutan behavioral repertoire, however it remains unclear to what extent food scarcity and canopy structure explain population differences in ground use.
(© 2015 Wiley Periodicals, Inc.)
Databáze: MEDLINE
Externí odkaz: