80 The Ruffed Grouse 



THE EFFECT OF SLOPE ON SELECTION OF COVER TYPE 



Many factors enter into the choice of cover made by grouse broods. 

 Under most conditions the steepness and aspect of the slope is prob- 

 ably less important than some other factors. However, slope is of some 

 importance, directly or indirectly, in its relation to cover, plant 

 species, and weather (see page 93). The effect of slope on brood- 

 cover selection is essentially the same as for adults at the same season. 

 Steep slopes are generally avoided, even more so than with adults. 



COVER SELECTION IN RELATION TO OPENINGS 



The great importance of open cover types and openings (open 

 land, overgrown land, slashings, and roadways are classed as open 

 types or openings) to grouse is most strongly shown by the young 

 birds. While grouse are usually thought of as birds of the wood- 

 land, their need for openings and brushy cover is clearly indicated. 

 Three quarters of all grouse broods are found in or within a few 

 feet of an opening or open cover type, and almost all stay within 

 fifty feet of openings. 



Thus the young biids utilize a relatively small proportion of the 

 cover in most areas, especially forest areas. The need for intersper- 

 sion of the open types with woodland types is apparent if the range 

 is to have a high grouse production capacity. 



COVER TYPES CHOSEN AS AFFECTED BY W^EATHER 

 CONDITIONS 



Cover-type selection by broods is somewhat more stable under 

 varying weather conditions than is the case with the grown birds. 

 The most important type used, overgrown land, does not vary sig- 

 nificantly in use under any conditions of temperature, sky, or wind. 

 It is thus an all-weather type for birds in summer, which is prob- 

 ably one of the factors bearing on its importance. 



Changes in temperatures affect cover type selection the least of 

 the three weather attributes. As usual the most significant changes 

 occur in the use of confferous woods. These are used much more 

 than average on hot days, and correspondingly less on cold days. 

 Although this relative preference for conifers as a place of escape 



