'j;i THE SI'KCIES ITS TAXONOMY, RANGE, BIOLOGY, ct ECONOMIC IMI'OKTANCE 



carefully based on the meager facts available. 



Perhaps the clearest idea of the weipht-health relationship may be gained by studying fig- 

 ure 11. By comparing the weight of the birds collected or picked up dead at any period of 

 the year, with the average here presented, a fair diagnosis of their relative state of health 

 may be made. 



Of course, one may also utilize his own judgment of the condition of the bird, but unless 

 one is thoroughly skilled in such matters, rule-of-thumb methods, such as the mere hefting of 

 a bird shot in the field or estimating its condition by the relative sharpness of the breastbone, 

 are notoriously unreliable. Many times grouse have been shot and sent to the Laboratory, as 

 seriously diseased, simply because a few of the long roundworms ( Ascaridia) , found upon 

 cleaning, have predisposed a hunter to judge that the bird was poor in flesh. Actual weight 

 comparisons with those given in the table, while of course in no way absolute, will provide, 

 in most cases, the best method of appraising in New York, and probably throughout the 

 Northeast, the general health of grouse. 



MEASUREMENTS 



In general, adult grouse do not vary greatly in size, especially with respect to their skeletal 

 structure, although males tend to be slightly larger than females. Unfortunately, time has not 

 permitted detailed measurement of the majority of the specimens which the Investigation has 

 taken. 



With respect to the eastern races of the species, the following as recorded by Forbush'", 

 is representative. 



"Length 15.50 to 19.00 in.; spread 22.00 to 25.00; folded wing 6.90 to 7.50; tail 5.50 

 to 7.00; bill from nostril .50 to .53; tarsus 1.50 to 1.60." 



An interesting note by Poole™ gives 527 sq. cm. as the wing area of a grouse which 

 weighed 516.5 grams, or a relationship of 1.02 sq. cm. per gram. 



In a series of adult birds collected in New York State between January and April, however, 

 a record was kept of the length of the middle tail feathers, the results of which follow. 



TABLE 12. LENGTH OF CENTRAL TAIL FEATHKHS OF ADULT GROUSE FROM 



NEW YORK STATE 



It should be notc<l that, while not found in this series, overlapping in length between the 

 two sexes does occur*. Smyth'"' also measured a scries of specimens in which the tails of 

 the males averaged 1.17 inches longer although there was only seven nnn. dilTcrciice between 

 those of the shortest male and the longest female. 



VOICE'' 



Allliough their vocal organs are of a primitive tyi)e. grouse can produce a wide variety 

 of sounds. To many whose experience has been limited to the wild, this may seem an over- 



* Sec dianiidiiun Hnw tii RcroKni/e Sex, p. 39. 

 A By Waller f. Criuey. 



