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Hanya G, Kiyono M & Hayaishi S (2007) Behavioral thermoregulation of wild Japanese macaques: comparisons between two subpopulations. American Journal of Primatology 69: 802-815.
Abstract
We studied the behavioral thermoregulation
of Japanese macaques in two troops that live
in the coniferous (1000-1200 m in elevation)
and coastal forests (0-200 m in elevation)
of Yakushima. Frequency of sunbathing, huddling,
and microhabitat selection during inactivity
was compared. The difference in mean annual
air temperature between the forests was more
than 7 C. In both forests, when the weather
was clear, macaques spent more time being
inactive in the sunshine in winter than in
autumn. In winter, they huddled more often
when it was clear than when cloudy. Microhabitat
selection to stay in the sunshine during
winter differed between the two forests.
In winter, macaques spent more time inactive
in open habitats in the coniferous forest
and in the trees in the coastal forest than
in autumn, respectively. This difference
is related to the lower crown height in the
coastal forest and the large open habitats
(logged area) available only in the coniferous
forest. In winter, skin temperature measured
by temperature-sensitive transmitters was
1.32-1.71 C higher when sunbathing, and 0.83-4.75
C higher when huddling than staying in the
sunshade without huddling. In winter, the
proportion with which they stayed in the
sunshine or huddled in winter did not differ
between the two forests, in spite of the
difference in air temperature. This suggests
that Japanese macaques respond to seasonal
changes in air temperature, not the absolute
temperature, and that they acclimatize themselves
to thermal conditions that require behavioral
thermoregulation only during the season when
thermoregulation is most costly.
Keywords acclimatization; huddling; Macaca fuscata;
sunbathing; Yakushima
<Written by: Goro Hanya (hanya.goro.5z<atmark>kyoto-u.ac.jp)>
<Contact: Goro Hanya (hanya.goro.5z<atmark>kyoto-u.ac.jp)>
<Last update: June 27, 2007>