. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 960 M A M M AI; IA N III H I'.li N A TI (>\ 79 As the temperature of a hibernating mammal falls, so docs its metabolism, and this reduction may be calculated if a tempera- ture coefficient is assumed. Values near are characteristic of many biological systems and have been described for isolated tissues in hibernating and other mammals (South, 1958; Meyer and Morrison, I960). Figure 3 shows the effect of lowering the temperature in such a system. With a 30° drop, a small bat would last the 200 days, but with no
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 960 M A M M AI; IA N III H I'.li N A TI (>\ 79 As the temperature of a hibernating mammal falls, so docs its metabolism, and this reduction may be calculated if a tempera- ture coefficient is assumed. Values near are characteristic of many biological systems and have been described for isolated tissues in hibernating and other mammals (South, 1958; Meyer and Morrison, I960). Figure 3 shows the effect of lowering the temperature in such a system. With a 30° drop, a small bat would last the 200 days, but with no margin for a lower average fat level or a higher average metabolism (ef. above). For f/m = 1/4, a kg or more of body weight would be required. A further depression of the LOG FAST in DAYS. LOG Fig. 3. Influence of body temperature on fasting time in mammals of different size (Qio = and f/m = l). metabolism is required in smaller mammals and such is indeed seen (Kayser, 1940), but this necessitates a higher Q10. The influence of variation of <^10 on the fast duration at a representa- tive hibernating temperature of 10°C (T = -25°) is shown in Figure 4 for various (^]u values. At /' m -~- 1/4, a Qjq of is necessary for survival of a small bat. Interestingly, a Qio close to this, , may be calculated from the data of Hock (1951) on Myotis, between 2 and 40 ('. Another quantity relating to hibernation that may depend on body weight is the difference between the ambient and body temperatures. Figure 5 shows this in an experiment on a thirteen- lined ground squirrel, in which the TA passively followed the Tb. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Harvard University. Museum of Comparative Zoology. Cambridge, Mass. : The Museum
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