WEST 



ADAMS: I would suggest that there must be a constant differ- 

 ence in the relationship between the shivering index as you have it 

 and the oxygen consumption, since you do have a straight line 

 relationship. And if this is true, then perhaps we have a frequency 

 recording artifact all the way along the scale, not just at one peak. 



WEST: The frequency of shivering is very low at the higher 

 temperatures and we do record that faithfully, because it only goes 

 up to around 200 cycles per second or so, but our recent analysis 

 shows that intense shivering goes as high as 700 c.p.s. 



PROSSER; Of course you have to sacrifice the bird, but just 

 as a check it might be useful to do phosphocreatine breakdown. I 

 would like to ask one question about the fact that you find no differ- 

 ence in the slope or in the shivering response with the seasons, 

 but do find that the winter birds can maintain their metabolism 

 longer under cold stress. Now, this suggests that acclimatization 

 may be an endocrine phenomenon. Have you any information about 

 the state of the adrenal cortex? 



WEST: Not about the adrenal cortex, but a little on the thyroid. 

 But Wilson and Earner, and Oaksen and Lillie have found that the 

 thyroids of permanent resident birds that were held in one spot 

 increased in the winter time because the temperature fluctuated 

 greatly, which corresponds to the permanent resident metabolic 

 acclimatization. But birds studied on their wintering ground in 

 California and on their summer ground in Alaska, showed no differ- 

 ence in thyroid, 'Taecause" they experienced a temperature fluctua- 

 tion both summer and winter of 5 G, whereas those maintained 



o 

 in Washington had a temperature fluctuation of 20 C. This may be 



a tie-up there, although this is very tenuous, and there are results 

 in thyroid activity going in the other direction for some species. 

 I do not know anything about the adrenal. 



IRVING: I look at migratory birds from the wrong end. I mean 

 from the unconventional end of being on the arctic ground where 

 the birds arrive after migration, instead of in the temperate places 

 from which they are preparing to start. It has always been 



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