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Sleeping Tree Selection of C ao V it Gibbon ( N omascus nasutus ) Living in Degraded Karst Forest in B angliang, J ingxi, C hina
Author(s) -
FEI HANLAN,
SCOTT MATTHEW B.,
ZHANG WEN,
MA CHANGYONG,
XIANG ZUOFU,
FAN PENGFEI
Publication year - 2012
Publication title -
american journal of primatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.988
H-Index - 81
eISSN - 1098-2345
pISSN - 0275-2565
DOI - 10.1002/ajp.22049
Subject(s) - predation , liana , nocturnal , ecology , predator , sleep (system call) , home range , biology , range (aeronautics) , china , zoology , geography , habitat , materials science , composite material , computer science , operating system , archaeology
We studied the sleep‐related behavior of two C ao V it gibbon ( N omascus nasutus ) groups in B angliang N ature R eserve in J ingxi C ounty, C hina between J anuary 2008 and D ecember 2009 to test four hypotheses related to sleeping tree selection (predation avoidance, thermoregulation, food access, and range defense). Gibbons entered sleeping trees 88 ± SD 37 min before sunset before their main potential nocturnal predator become active. They usually moved rapidly and straight to sleeping trees and kept silent once settled. Over the course of the study, gibbon groups used many (87 and 57 per group) sleeping trees and reused them irregularly. They also tended to sleep in relatively tall trees without lianas, choosing small branches close to the treetop. These behaviors would make it difficult for potential terrestrial predators to detect and approach the gibbons. Therefore, these results strongly support the predation avoidance hypothesis. Gibbons tended to sleep closer to ridges than to valley bottoms and they did not sleep at lower elevations in colder months. They thus appeared not to select sleeping trees to minimize thermoregulatory stress. Gibbons very rarely slept in feeding trees, instead generally sleeping more than 100 m away from the last feeding trees of the day or the first feeding tree of the next morning. These patterns led us to reject the food access hypothesis. Lastly, we did not find evidence to support the range defense hypothesis because gibbons did not sleep in overlap areas with neighbors more often than expected based on the proportion of overlap and exclusively used areas. Am. J. Primatol. 74:998‐1005, 2012. © 2012 Wiley Periodicals, Inc.