Thermal energetics of the New-Guinean moss-forest rat (Rattus niobe) in comparison with other tropical murid rodents |
| |
| Institution: | 1. Dipartimento di Scienze della Terra e del Mare, Università di Palermo, viale delle Scienze, Ed. 16, 90128 Palermo, Italy;2. Dipartimento di Scienze Biologiche ed Ambientali, Università di Messina, salita Sperone, 31, 98166 Messina, Italy;3. IAMC-CNR, via G. da Verrazzano, 17, 91014 Castellammare del Golfo, TP, Italy;1. Zoology Department, Oklahoma State University, United States;2. Department of Fisheries, Wildlife, and Conservation Biology, Bell Museum of Natural History, University of Minnesota, United States;3. Minnesota Pollution Control Agency, United States;4. Institute for Applied Ecology and Collaborative Research Network for Murray-Darling Basin Futures, University of Canberra, Australia;5. Oklahoma Cooperative Fish and Wildlife Research Unit, Oklahoma State University, United States;6. Department of Zoology, Weber State University, United States;1. School of Animal Biology, The University of Western Australia, Crawley 6009, Australia;2. Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Canberra 0200, Australia;3. Kings Park and Botanic Gardens, The Botanic Gardens and Parks Authority, Fraser Avenue, West Perth 6005, Australia |
| |
| Abstract: | The thermal energetics of rodents from cool, wet tropical highlands are poorly known. Metabolic rate, body temperature and thermal conductance were measured in the moss-forest rat, Rattus niobe (Rodentia), a small murid endemic to the highlands of New Guinea. These data were evaluated in the context of the variation observed in the genus Rattus and among tropical murids. In 7 adult R. niobe, basal metabolic rate (BMR) averaged 53.6±6.6 mL O2 h−1, or 103% of the value predicted for a body mass of 42.3±5.8 g. Compared to other species of Rattus, R. niobe combines a low body temperature (35.5±0.6 °C) and a moderately low minimal wet thermal conductance cmin (5.88±0.7 mL O2 h−1 °C−1, 95% of predicted) with a small size, all of which lead to reduced energy expenditure in a constantly cool environment. The correlations of mean annual rainfall and temperature, altitude and body mass with BMR, body temperature and cmin were analyzed comparatively among tropical Muridae. Neither BMR, nor cmin or body temperature correlated with ambient temperature or altitude. Some of the factors which promote high BMR in higher latitude habitats, such as seasonal exposure to very low temperature and short reproductive season, are lacking in wet montane tropical forests. BMR increased with rainfall, confirming a pattern observed among other assemblages of mammals. This correlation was due to the low BMR of several desert adapted murids, while R. niobe and other species from wet habitats had a moderate BMR. |
| |
| Keywords: | Altitude Basal metabolic rate Climate Muridae Rainfall Temperature Thermal conductance |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
