HETEROTHERMY IN HOMEOTHEPMS 



availability of food to the animal. It is extraordinary when an animal 

 has more food than he can eat everyday. This is certainly not what 

 you would expect arctic mammals to be confronted with in his natural 

 environment. 



HANNON: That is true, but if we had attempted to control caloric 

 intake we would have biased our results by the mere fact that you are 

 controlling the amount of food available. 



IRVING: He is thinking that the dog chooses to eat more when 

 excess food is available. Why he chooses to eat is a different thing. 



MORRISON: I might add that our appetite in cold weather 

 exceeds the thermoregulatory needs of the body. 



HANNON: After the first two or three weeks of over-eatinr: 

 they reduced their intake and it remained fairly constant from day 

 to day. However, when you consider these daily intakes over a 

 period of months the differences between the seasons are signifi- 

 cant, and there is a significant correlation between temperature 

 and food consumption. 



HART: Have you done this over the whole winter and summer? 



HANNON: On the huskies, we have it starting with November 

 of one year and continuing through November of the following year. 



MORRISON: How about the beagles? 



HANNON: The reason we used beagles is interesting in itself. 

 We started these feeding experiments on huskies on the first of 

 October and commenced our measurements of food intake on 

 the first of November. As I mentioned earlier, there was a decline 

 in food intake between November and the later portions of the 

 winter. This did not seem quite right; so in midwinter we decided 

 we had better look at dogs that were not so we 11- insulated as the 

 huskies. Beagles seemed to offer a good choice. They were pur- 

 chased in California and brought to Alaska, where they were housed 

 indoors for four weeks. During this period they were allowed two 

 weeks to adapt to the same diet as the huskies and two weeks 



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