75U I'lnSlOLOGlCAL STL DIES OF THE RIFFEI) GliULSE 



The ideal situation for measuring iihysiolopicai responses of animals in relation to specific 

 environmental londitions would be to conduct an investigation outdoors under natural con- 

 ditions. Such a procedure would be most diflit ult. if not impossible. Wild animals are. there- 

 fore, taken into the laboratory where they can be better controlled and where the various 

 phases of their physiology can be investigated in orderly sequence under both constant and 

 changing conditions. In this way it is possible to determine the degree of adjustment required 

 to compensate for various changes in the cn\ ironnient. 



The present slud\ of the ruffed grouse was conducted in a calorimeter cabinet designed by 

 the author and constructed at the laboratorx. The gross dimensions of the caljinct are 15 feet 

 long. 10 feet wide, and Kl feel high with a wall thickness of 10 inches. It contains three 

 separate compartments in each of which physical factors may be held constant automatically 

 or varied indepcndcntl). Means are ])rovided for accurate control of air temperature, light, 

 humidity and air movement. The temperature can be varied over a range from — 40°F. to 

 over 1S0°F. with an insignificant differential. Facilities have also been installed for simulating 

 rainfall through spraying the birds with either warm or cold water at different air tempera- 

 tures. One of the compartments was used for preliminary physiological adaptation of birds 

 to specific enviromnental conditions. The others accommodated an entire respiration appar- 

 atus for measuring heat production as well as other equipment and instruments, if desirable, 

 however, each of the latter compartments can be used as a calorimeter chamber for measuring 

 the gaseous metabolism of either large or small animals. 



Weights were taken, in the main, on a balance with accuracy to within one gram. In cer- 

 tain studies, however, weighings were made on an anahtical balance accurate to one milli- 

 gram. Weighings were secured at definite times during the morning from o:(M) to 10:00, 

 during the afternoon from 4:00 to 6:00, and frequently at midnight or other hours. 



Muscular movements of the body (cage activity) with respect to amount and intensity at 

 different environmental conditions and nutritional levels were recorded graphically by means 

 of tambours, ink-writing pens, and an electrically rotated kymograph drum. Cage activity 

 was reproduced by means of the recording pens writing antomalicali\ on standard cross- 

 section paper 26 x 100 inches long scaled in millimeters. 



Records of iiocK tcmi)crature were secured b\ means of calibrated nuTcur) or electric 

 thermoc(iU|de thermometers. A |)rcIimiMar\ cxpcMiment re\ealed that a body temperature com- 

 paralilc to that of the gizzard could be secured by inserting a thermometer at least 2 inches 

 into tile rectum of a grouse. 



The breathing rale was clctci niiricd b\ counting respiratory movements as visually observed 

 on various |)orlions of the external b<>d\ surface or by ])lacing the bird in a cage and obtain- 

 ing a graphic rec-ording of the res|)irator\ niovcTncnt 1)\ means of the k\ mograpli. 



Records of iuail beat were secured li\ using a sensitive stethoscope and s\ nc hronizing 

 the sound with "hand-tapping" a ])encil point cm mci\ing pa|)cM- or the |irc-ssing of an auto- 

 matic electric counter. 



Various special ici hnicpics were devised ij\ ihc aiiliioi to iiuct specific needs as the work 

 proceeded. 



In |)lanning the studies to be condncted emphasis was placed on securing information per- 

 taining to the general plnsiological characteristics of the species which might ha\e a bearing 

 on management practices as well as to securing basic data* prerequisite to conducting more 



♦ UnforciinaCely urmrc ilurn not [icnnil llie incluitiiin of niuiiy artuils. liolli i\tlli rrtp.-.t lo .lata ami In liniiiucit rni|ili)>r.l, wliicli 

 have been invoUeil in thii project. 



