THERMOREGULATION IN MAMMALS 

 FROM THE TROPICS AND FROM HIGH ALTITUDES* 



Peter Morrison 



The title presents something of a problem since there may 

 well be no real entity "thermoregulation in tropical mammals" 

 such as we see in other environments as the desert or the arctic 

 which make special demands and have elicited special physiological 

 capabilities. The tropics are distinguished in a negative rather 

 than in a positive sense, by the lack of demands, at least of thermo- 

 regulatory demands, which are placed on the inhabitants. As has 

 been pointed out, this region has a much better claim to the title 

 of "temperate" than do our own middle latitude regions where 

 extremes of temperature and rainfall are characteristic. But there 

 are certain groups of animals which may be considered character- 

 istic of these regions so that we can at least discuss thermoregula- 

 tion in "some tropical mammals." However, these may well be 

 characterized by a deficiency in regulatory ability rather than any 

 special attributes for life there. The monotremes, and the edentates, 

 might be considered in this catagory, but these groups have already 

 been reviewed as primitive forms by Dr. Johansen. So I propose to 

 survey first, the marsupials, then a primitive eutherian group, the 

 Ghiroptera, and finally the more advanced group of the Primates; 

 all of which we can think of as characteristically tropical, although 

 some representatives extend beyond this zone. 



'• *Much of the data discussed in this paper is as yet unpublished. Studies on 

 Brazilian monkeys were carried out with J. Simoes, Jr.; on the pigmy marmosette 

 with E. Middleton; on new world tropical bats with B. K. McNab, who also parti- 

 cipated together with K. Kerst and W. H. Holthaus in the studies on high-altitude 

 mammals. Support for these studies has been variously received from the Guggen- 

 heim Foundation, the U. S. Educational Foundation in Australia, NSF, NIH-PHS, 

 WARF, ONR, and the Rockefeller Foundation. 



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