A STUDY OF THE BODY TEMPERATURE OF BIRDS 

 By ALEXANDER WETMORE, 



BIOLOGICAL SURVEY, U. S. DEPARTMENT OF AGRICULTURE 



CONTENTS 



Introduction i 



Method of securing avian temperatures 3 



Diurnal rhythm in temperature • 5 



Table i. Time of maximum and minimum temperatures in birds 5 



Variation in temperature in relation to sex g 



External temperature in relation to bodily heat 12 



Diverse miscellaneous factors in their relation to body temperature 16 



Temperature of young 18 



Table 2. Temperatures of young or nestling birds 19 



Method of temperature control in birds 21 



Significance of temperature control 28 



Discussion of differences in average temperatures 30 



Explanation of tables 32 



Table 3. Summary of temperature records 36 



Table 4. Average temperature of families of birds, summarized from 



Table 3 47 



Table 5. Temperatures of species of birds not included in Table 3, 



taken from available literature 48 



Bibliography 51 



INTRODUCTION 

 The subject of the body temperatures of the many and varied 

 species that compose the great vertebrate class of birds is one that 

 in the past has been rather shghtly treated by those interested in 

 avian physiology. Statements to the effect that the bodily tempera- 

 tures of birds are higher than in others in the group of classes com- 

 posing the Vertebrata, are current in many zoologies and text books, 

 but on the whole, literature gives few definite statements of fact on 

 the subject, and observations have been restricted to a comparatively 

 small number of species. In the course of other work many hundreds 

 of birds have been handled in the flesh by the present writer, and 

 after some thought methods were devised for the taking and record- 

 ing of body temperatures in as accurate a manner as possible. This 

 was a little known field of endeavor and at first no guides as to method 



Smithsonian Miscellaneous Collections, Vol. 72, No. 12 



