120 



COVER CHARACTERISTICS AND SHELTER REQUIREMENTS 



conifers that replace them. 



WTiere the crown cover is sufliciently dense to maintain fairly open conditions beneath, such 

 woods are often chosen as spring nesting grounds; where they are more open and the herbs 

 and ferns thicker, they furnish considerable summer feed. With the addition of clumps of 

 shade-loving conifers, such as hemlock, spruce or of the more light-demanding pines and 

 balsams (the latter usually started while the land was not yet heavily wooded), the require- 

 ments of the grouse for shelter, especially in winter, may also be met. 



As the forest matures and closes in. barring action by Nature or man to create openings, 

 most summer and fall feed gradually disappears. The birds are then forced to seek a more 

 congenial habitat along the edges. Let a wind storm create openings by uprooting the less se- 

 curely anchored trees, or a lumbering operation open up the cover, and the succession is set 

 back accordingly. In the openings thus created herbs, briers and berries quickly spring up 

 thus again providing abundant feed for old and young alike. 



Then the birds move in again. 



Thus goes on the ]iageant of succession. By it, the grouse are pushed hither and yon, ever 

 seeking the places where winter shelter, spring breeding grounds and summer and fall feed 

 lie close together. On these they must depend to a greater extent than is generally realized, 

 for the essentials of their existence. In these they find varying degrees of protection from their 

 several enemies whose success depends largely on finding the birds in the poorer cover. 



COVER TYPES RECOGNIZED 



Botanists and foresters divide the various stages of succession through which a woodland 

 may pass into cover types. The hunter, perhaps unconsciously, long ago applied the same 

 technique as an aid in finding his birds in the fall. The basis of recognition, in one case, 

 is largely what prows there; in the other, the use the birds make of the plants. Thus a scat- 

 tering of thornapples. cherries and dogwoods along a wood's edge becomes known as likely 

 fall feeding grounds for the grouse. The emphasis is here clearly and rightly placed on use. 



But the intricacies of cover are such that no clear picture of use can be olitaiiied from 

 chance observations alone. Neither is it practical to classifv cover into innumerable small 

 subdivisions, for the number of records needed to determine to what extent each fulfills grouse 

 cover requircrncnls is too great in the face of the varied habits of the bird. Based on experi- 

 ence, the Investigation gradually came to recognize the following twelve major cover types, 

 representing four major stages of succession. (Table 13). 



TABLE 1.3. EXPLANATION OK THE C0\ EM TYPES AND SYMBOI>S USED L\ 

 THE RUFFED GROUSE INVESTIGATION. 



