NUMBER OF EGGS LAID 



363 



between this figure and the general average is of little importance. 



The one comparison that seems to hold real significance is that of the Adirondacks with the 

 Rest of the State. The .7 egg difference, 11.0 to 11.7, between the Adirondack nests and all 

 others in the State, is considerable since it represents 6 per cent of the number of eggs laid. 

 This difference is significant by statistical analysis since the mathematical probability of its 

 being true is more than the 19 to 1 required. 



A possible explanation of the lower egg-laying average of Adirondack grouse may lie in a 

 repressive influence of the environment on the birds' reproductive ability. For grouse the car- 

 rying capacity of the extensive forests in northern New York is far below that of the discon- 

 nected coverts through the rest of the state*. It is at least a possibility that the level of egg 

 laying might thus be affected. 



It is improbable that the physical ability of the female to lay eggs is reduced in the Adiron- 

 dack environment, even though winter weather conditions are more severe and habitat 

 generally less suitable than farther south. It is more likely that the rapid change of seasons 

 during the breeding period may result in a shortening of the time when grouse have the urge 

 to lay. The late spring causes a delay in nesting of about a week behind the rest of the State 

 but by the middle of May the seasons have become equalized. Thus, there may be a seasonal 

 time factor operating to give these northern birds a smaller average clutch size. 



A TYPICAL CLUTCH OF GROUSE EGGS 



The average number of eggs laid by Catskill grouse lies between that of the Adirondacks 

 and the area of disconnected coverts. Likewise, the character of the Catskill range is inter- 

 mediate in that the coverts are in rather large blocks, more so than is the case with the discon- 

 nected coverts area but not nearly as continuous as the Adirondack forest. There may be 

 significance in these parallels. Summarized, it might be that the carrying capacity of different 

 types of range is an indicator of the average number of eggs the birds will lay. Regional 



* See Clmpter XU, p. 525. 



