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International Journal of Zoology
Volume 2010, Article ID 921371, 9 pages
http://dx.doi.org/10.1155/2010/921371
Research Article

Size-Related Differences in the Thermoregulatory Habits of Free-Ranging Komodo Dragons

1Department of Zoology & Physiology, University of Wyoming, Laramie, WY 82071, USA
2Komodo Survival Program Indonesia, Jalan Pulau Moyo Komplek Karantina, Blok 4 No. 2 Denpasar, Bali 80222, Indonesia
3Department of Zoology, University of Melbourne, Parkville 3010, Australia
4Conservation and Research for Endangered Species, Zoological Society of San Diego, Escondido, CA 92027, USA

Received 11 January 2010; Accepted 14 June 2010

Academic Editor: Tobias Wang

Copyright © 2010 Henry J. Harlow et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Thermoregulatory processes were compared among three-size groups of free-ranging Komodo dragons (Varanus komodoensis) comprising small (5–20 kg), medium (20–40 gm) and large (40–70 kg) lizards. While all size groups maintained a similar preferred body temperature of 35 , they achieved this end point differently. Small dragons appeared to engage in sun shuttling behavior more vigorously than large dragons as represented by their greater frequency of daily ambient temperature and light intensity changes as well as a greater activity and overall exposure to the sun. Large dragons were more sedentary and sun shuttled less. Further, they appear to rely to a greater extent on microhabitat selection and employed mouth gaping evaporative cooling to maintain their preferred operational temperature and prevent overheating. A potential ecological consequence of size-specific thermoregulatory habits for dragons is separation of foraging areas. In part, differences in thermoregulation could contribute to inducing shifts in predatory strategies from active foraging in small dragons to more sedentary sit-and-wait ambush predators in adults.