PHYSIOLOGICAL STUDIES OF THE RUFFED GROUSE 



773 



body tissue which had been destroyed as a result of fasting. The importance of the water 

 relationship in maintenance of body weight has been presented in a preceding experiment. 



An interesting observation is that even among birds showing a steady net gain some weight 

 was lost each night when no food was eaten. 



In table 118 are listed the calculated amounts (in calories) of the foods used which should 

 have satisfied the physiological needs of the birds studied under the environmental conditions 

 specified. The caloric intake determined at 6.5°F. and at 85°F. should maintain body weight 

 within the limits of normal 24-hour fluctuations; and at 65°F. should maintain (1) an 

 average body temperature of 107.3°F. plus or minus the limits marked by diurnal range; (2) 

 an average respiration rate of about 63 per minute; and (3) an average heart rate between 

 300 and 38.5 beats per minute or an average rate of 342.6 beats per minute. 



T\HL1': 118. CALCULATED DAILY CALORIC INTAKE OF FOOD NEEDED BY ADULT 



GROUSE TO MAINTAIN WEIGHT AND VIGOR* 



♦Applies fully to the birds iiserl in these studies and the eoiiditioiis under which exiieriment-s were eondiict«'d. 



According to the data, approximately 3.6 calories (biological value) are required to pro- 

 duce one gram of body substance containing 0.40 calories at 6.5°F. Although the data are 

 slightly inadequate for predicting the caloric value per gram substance relationship at higher 

 air temperatures, it may be estimated with a fair degree of accuracy that about 2.0 calories 

 are required lo produce one gram of body substance cdntaining 0.50 calories at 8.5'F. 



