DIET 217 



Regional Variations in Foods Eaten 



A grouse, could it traverse all the wild lands of New York State, would find a great var- 

 iety of habitats. The partly sandy, partly granitic Adirondack Mountain region contains 

 coverts in many essentials representative of much ruffed grouse range in the Northeast. 

 The high-dunied, sedimentary-rocked Catskill Mountains in the warmer southeastern part 

 present an equally distinct set of conditions, in many respects comparable to those of por- 

 tions of the Appalachians. The surrounding regions, together with the Allegheny Plateau, 

 stretching westward across the southern and southwestern part of the State, represent a 

 third type of habitat distinct from the others in important respects*. 



The variations (table 28) between the plant foods that the grouse take in these three 

 regions, even at the same season of the year, are rather surprising. Differences in weather 

 and in plant dislriluilion, of course, play their part, but it is not always easy to ascribe 

 all the shifts in jireference to these factors alone. 



However, the grouse show a distinct tendency to concentrate their feeding on certain 

 favorites at each season. These are largely the same throughout the State, except in the 

 Catskills. This difference is puzzling, for the most-used groups, the poplars, birches, thorn- 

 apples and hop-hornbeams, are well distributed throughout all three regions. A partial 

 explanation for a dietarv difference in the Adirondacks may lie in the fact that deep 

 snow covers most of the low-growing foods throughout the winter and well into the spring. 

 The birds are accordingly forced to concentrate on the buds of a comparatively few spec- 

 ies. The same situation holds to a lesser extent throughout the State, though this influence is 

 offset in most regions by an earlier spring. 



In the Adirondacks <!9.7 ])er rent of the food in winter, and 86.7 per cent in spring, is 

 provided by the ten most-used groups of plants whereas in the Catskills but 60.7 per ccnl 

 of the winter food and 78.6 per cent of that of spring comes from these same sources. 



The prevalence of a food species in a habitat is not always an indication of its use 1)\ 

 grouse. For instance, in the Catskills in winter, the hop-hornbeam is the most sought after 

 species, with the aspens rating a |)oor eighth. Hut in the spring that follows, the situa- 

 tion is essentialh reversed, with the |)opIars first in importance and the hop-hornl)eams 

 fifth. Contrast lhi< uilii ihe record from the rest of the State, where in both winter and 

 spring poplar buds seem to be chosen in preference to hop-hornbeam buds and catkins. 

 Bolh species are connnon. Each rates among the first four chosen al some period of the 

 year in each region. Manv such inconsistencies of choice are found between the regions, 

 but by no means are all of these explainable on the basis of food availability- Perhaps a 

 larger number of birds needs to be examined. 



In general, llic products of poplars, birches and thornapples are universally preferred. 

 Cherries, though equally well distributed, are apparently budded mostly in the spring in 

 the Adirondacks. Here snow mav remain until very late. Likewise its disappearance in 

 the Catskills and o\er the rest of the State, early in the season may account for the com- 

 parative imporlanie of strawberrv leaves there. 



Sumachs are not so widely distributed in the Adirondacks. but in the Catskills and through- 

 out the rest of the State there seems to exist an interesting relation between them and the 

 beeches, for when beeches bulk high as a source of food, sumachs do not and vice versa. 

 Even so the choice is not always predictable. In the Catskills sumach is one of the important 



* A iTHire niiiiplt-h- (ii--rii['ti<in (if tlifsc rrgi.ms is (imnil in Cliaplcr UI. 



