THE ROLE OE COVER COMPOSITION AND INTERSPERSION 169 



cover to be found under a more varied crown canop> . This is one of the reasons why large 

 blocks of coniferous reforestation are apt to be productive of grouse largely along their 

 edges*. 



The age of the trees or shrubs that make up a type also exerts an influence on the cover. 

 Uneven-aged stands create breaks in the crown canopy. These let more sunlight filter 

 through thus encouraging a more abundant variety of shrubs and herbs beneath. The effect 

 of removing a few trees here and there in a woodland, known as selective cutting, has been 

 noted consistently in terms of increased use of the remaining cover (type G in the foregoing 

 tables) by botii broods and adults. 



The physical condition of the soil also has its effect. Fewer species are likel\ to thrive 

 on lands from which the fertility has been exhausted. Conversely, the presence of a diver- 

 sity of soils running from acid to alkaline, from wet to dry. and from gravel to loam, pro- 

 vides encouragement for a greater variety of plants, many of which are adapted only to par- 

 ticular situations. Such conditions, though seemingly small, should be taken into considera- 

 tion by an individual or state interested in purchasing or developing areas for grouse. 



On previous pages, the impression may have been created that, as long as grouse rover 

 contains an abundance of the various types which grouse frequent, it will produce a high 

 population of birds. Such is certainly not ahva\s the case. Patches of almost pure conifers, 

 dense hardwood sprouts, hawthorn thickets and second-growth maples, lying close by one 

 another, still would not provide acce])table winter shelter, spring breeding grounds and 

 summer and fall feeding areas to sui)|)ort many grouse. To be really productive there must 

 be present not nnlv a good arrangement i)f((i\er t\pes but also a variety of vegetation 

 within each. 



Of the two ideas, the former is. in principle, the belter understood. One thinks of a 

 badly laid out farm as a poor producing unit. In like manner grouse cover tliat meets the 

 food and shelter requirements of the birds for only a part of the year cannot produce a good 

 crop of partridges. The individual cover types, like the separate farm fields, may partially 

 fulfill the need of bird or farmer as the case may be. yet the whole be so organized as to spell 

 failure of the year's crop. 



The analogy has been used purposeK. though maii\ sportsmen as yet do not realize that 

 iheir shooting in the fall is largely dependent upon the co\er being so i)Ut together as to sat- 

 isfy the birds. Fortunately, in New York Stale, the axe and the economic conditions creating 

 much little used or abandoned farmlands have accidenlalh produced man\ fine coverts with 

 a high carrying caiiacily for grouse. The\ are the ones In which the hunter returns year 

 after year, always to find some birds. Hut there are others, and lhe\ mc in the majority, 

 which are less frequenlh hunted simply because ihe size of ibe bird crop is less predictable. 

 The most likely cause of this is poor arrangement of types. \o winter wood has been cut 

 there for some years; no cows have tramped down and ihtis kept the brushy pastures semi- 

 open. Almost imperceptibly the trees are closing in and growing taller. The light-demanding 

 vegetation is being gradually choked out. Here year by year individual grouse territories are 

 becoming larger and birds fewer as second-growth and mature cover types extend their 

 boundaries and the edges retreat farther and farther from their centers. 



Realizing this, wildlife managers responsible for developing better grouse coverts are 

 plamiing their plantings of trees and shrubs in abandoned fields to produce the maximum of 

 edges compatible with fulfilling other uses. Large blocks of conifers are giving way to strip 



» Scr tahlc IB. [<. 171. 



