## Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

## If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

# Hibernation and Daily Torpor in Two Pygmy Possums (Cercartetus Spp., Marsupialia)

Fritz Geiser
Physiological Zoology
Vol. 60, No. 1 (Jan. - Feb., 1987), pp. 93-102
Stable URL: http://www.jstor.org/stable/30158631
Page Count: 10
Preview not available

## Abstract

The physiology of torpor was investigated in the pygmy possums Cercartetus concinnus (18 g) and C. lepidus (12 g). Body temperatures ($T_{b}$) during torpor remained within 1 C of air temperature ($T_{a}$) and showed a minimum of about 5 C in both species. Oxygen consumption ($\dot{V}O_{2}$) during torpor was reduced to about 0.05 liters O₂/kg h, which amounts to only 1% of the rate of normothermic animals. Below $T_{a}$ of 5 C, the metabolism during torpor increased with a further decrease in $T_{a}$, while $T_{b}$ was regulated at about 5 C. Rates of arousal were faster than predicted for endothermic vertebrates of comparable size. Duration of torpor bouts ranged from less than a day to a week, with the longest bouts occurring at $T_{a}$ < 10 C. The physiological characteristics of torpor in these two marsupial species are qualitatively and quantitatively similar to those of placental hibernators.

• 93
• 94
• 95
• 96
• 97
• 98
• 99
• 100
• 101
• 102