754 P/nf^lOLOGIC IL STl DIES OF THE Rl FEED GROUSE 



fdrccri t(p run and mkim' ;ili(nil fni ten niituilt'>. aftiT which temperature and respiration were 

 again recorded. Ihe results of this test are sliown in figure S5. Thev indicate a significant 

 increase in both respiration rate and body temperature foUowing ten minutes of activity. 



Ekfkct of Rainfai.i, on Maintenance of Body Temperatire 



Experiment I itnolved a stud\ of the effect of rainfall under various conditions of air 

 temperature and air movement on the bird's al)ilil\ tu maintain its body temperature. Two 

 groups (A and C) of five grouse each, and one 1 15 I of six. were used. All were in a condi- 

 tion of active digestion during the tests. Rainfall was simulated in the experimental cabinet 

 by spraying water on the birds. Air movement was slow. Specific conditions for each group 

 were as follows: 



Group A — Exposed to Air Temperature 40° F.; Humidity, GO'^'i ; Water Temperature 44°F. 

 Group B — Exposed to Air Temperature 65°F.; Humidity, SO'i; Water Temperature 44°F. 

 Group C — Exposed to Air Temperature 80°F.; Humidity, 35%; Water Temperature 62°F. 



The results are shown in figure of). It is to be noted that in each case a sharp drop in 

 body temperature occurred during the half hour inunediatel) after the birds were wet. This 



20 40 60 80 100 120 140 160 180 200 220 2*0 280 280 300 



DURATION OF TEST IN MINUTES 



FIGIRE 86. TRENDS IN RECTAI, TEMPERATIRE FOLLOW IM. \\ K TTING AMONC, THREE (;R01PS OF 

 ADULT GROUSE EXPOSED TO DIFFERENT CONDITIONS OF AIR TEMPERATURE AND HUMIDITY 



was most severe and recoverv was slowest among Group A. which were exposed to a water 

 temperature of 14 F. at an air temperature of 4fl°F. Even at an air temperature of 80°F. 

 welting caused a marked and rapid fall in \un]\ temperature (Group C). The data clearly 

 show that wetting the binK willi u.ilir is a factor of considerable ])hysiological importance 

 in itself. The cdndiinatinn mI I.iu air temperature an<l wetting with water was >lill more ef- 

 fective sinie the rate nf (liii|i in IhkK tempcralnre w'as faster and rate of recovery slower. 

 I'nder conditions such as those to which Groups A and H were subjected, continued exposure 

 without good bodiK protection would cause death. 



