360 REPRODUCTIVE CAPACITY OF THE SPECIES 



and again three years later she was likewise caught at her nest. In 1937 her clutch was 13 

 eggs and in 1940 it was 12. The larger size of her second and, if she nested each intervening 

 year, fifth clutches as compared to the first one observed adds weight to the evidence that 

 the grouse usually lays a smaller clutch on her first attempt than in subsequent years. 



At the Research Center there is some indication to show that grouse lay fewer eggs after 

 their fourth vear. They seem to build up to a peak of production when three vears old and 

 to fall off slightly thereafter. One 6-year-old bird, which had previously laid larger clutches, 

 dropped to ten eggs in 1940. However, the wild bird noted in the preceding paragraph still 

 laid a normal sized clutch when at least five years old. 



The Investigtalion does not have evidence to show whether or not the birds continue to lay 

 beyond their sixth year. However, such an advanced breeding age is unimportant as a factor 

 affecting the reproductive capacity of grouse population. In New York, at least, only a very 

 small proportion live to the ripe old age of six years. 



Longevity and Senility 



In 1901, Edgar A. Mearns'" wrote: "Mr. Samuel Eldred of Wakefield. R. I., purchased in 

 December, 1900, a ruffed grouse from Mr. Joshua T. Bradley who stated that the bird was one 

 of several young grouse caught by him in 1883 and marked by clipping off their hind and 

 inner claws. This bird bore evidence of extreme age." And well it might, for if this record 

 were accurate, the bird must have lived to be 17 years old. 



More recent literature and the present records of the Investigation indicate that the average 

 adult grouse in the wild meets death before it is three years old. This is almost invariably a 

 violent death and. therefore, does not indicate the potential longevity of the species. As has 

 been mentioned, one banded wild grouse attamed an age of at least five years. At the Research 

 Center, 4-year-old birds are fairly numerous, while 5-year-olds are not unusual. Six-year-olds, 

 however, are rare and no bird has yet exceeded this age. 



At five or even six years of age. most grouse in captivity still ajjpear vigorous and healthy. 

 Occasionally they exhibit the effect of long confinement by acquiring feather injuries or 

 scalped heads, but the males mate successfully and females lay good clutches nonetheless. Wild 

 birds seldom attain such an age. and hence, one concludes that there is but slight chance that 

 the infirmities characteristic of senility could appreciably affect grouse populations. 



NUMBER OF EGGS LAID 



In considering reproduction, the number of eggs that a female bird lavs is important. If 

 it were to change appreciably at any time, the possibilities for the hunting season might well 

 be similarly changed. 



The evidence gathered by the Investigation in New York during the past 1 1 years, how- 

 ever, does not bring out auv appreciable changes in egg laving proclivities. On the basis of 

 1,473 grouse nests examined between 1931 and 1941. the mnuber of eggs found therein has 

 remained relatively constant. The minor fluctuations that have occurred were not such as to 

 have materially affected the population changes that followed. 



Table .50 summarizes these records. It has been divided into |)arts representing the three 

 areas of the state, as in other portions of the book, with the exception that the Connecticut 

 Hill data have been se|)araled from that of the ''Rest of State". This seemed advisable because 

 of the larpe number of nests observed on this studv area. 



