92 The Ruffed Grouse 



found a general limit of three hundred feet, beyond wliich the birds 

 did not penetrate the solid coniferous stands. In this case, few grouse 

 ventured more than two hundred feet from the outside edges. In 

 ordinary range we find this three-hundred-foot distance to be a good 

 rule of thumb for all woodland types, although most types are used 

 regularly in the two-hundred-to-three-hundred-foot zone. Even the 

 brushy cover types are relatively little used at a distance of more 

 than three hundred feet from the edges when present in large uni- 

 form blocks. 



We conclude that cover types should be so interspersed that no 

 point is over three hundred feet from an edge (between open or 

 brushy type and woodland type) if the range is to be fully and 

 regularly used. The optimum zone of woods types is from the edge 

 to a depth of two hundred feet. 



VARIATION IN COVER TYPE PREFERENCE AT 

 DIFFERENT TIMES OF DAY 



There are numerous factors that combine to determine the type of 

 cover selected by a grouse at any given time. We have just observed 

 the marked variation in the different seasons. Less marked, but still 

 highly significant, are the differences in cover needed at various 

 hours of the day within the seasons. Seasonal requirements must be 

 met within the limits of the bird's yearly range— a reasonably flex- 

 ible limitation— but the hourly changes required must be available 

 within the daily cruising radius. 



During the fall and winter the most significant trends are: a high 

 early-morning-use intensity of coniferous woods, hardwoods, slash- 

 ings, and overgrown land, all generally declining in use intensity 

 through the day; a low intensity in the early morning for mixed 

 woods, which rises through the day. All these trends are logical, 

 except that it would seem that the trend for use of coniferous woods 

 should parallel that for mixed woods instead of the hardwood 

 group. The fall and winter season use of the several deciduous 

 types at early morning feeding time, most notable in the fall, are 

 linked with the birds' feeding habits. 



In spring the hourly cover-type-use trends shift somewhat from 

 those of winter. The use of mixed woods rises from early morning 

 until midafternoon as before, but then significantly drops again 



