80   JOURNAL OF WILDLIFE MANAGEMENT, VOL. 6, No. 1, JANUARY 1942 
 
when the average volume of grit is less 
than 3.0 cc. Below that point, the bulk 
of seeds exceeds that of grit. There is a 
tendency to reduce the volume of both 
hard seeds and gravel in grit groups 
 
of this species hard seeds substitute for 
grit except under unusual conditions, 
as few such seeds are available in 
Ptarmigan habitat. These birds are 
found among massive rocks above 
 
8                                          w 
_           a                           a 
 
FIGURE 6w ww 
-0 
Ir 
 
0   - (0    'W 4)     7   0 
*0 I  I 
 
Fig. 6. Grit: hard-seed relationship as based on one cc. groups of grit.

 
3-4, 2-3, and 1-2. The quantity of hard 
seeds instead of increasing with the de- 
creasing volume of grit, decreases 
slightly as compared with the next 
lower bulk of hard seeds. 
For these crows, according to Wing 
(1940), "Corn, Dogwood, Dwarf Su- 
mac, and Poison Oak were the principal 
food species." All of these plants except 
corn furnish grit-supplanting seeds. It 
is possible that more complete extensive 
collections would show a greater tend- 
ency toward grit replacement. 
WHITE-TAILED PTARMIGAN 
(Lagopus leucurus) 
Only four specimens of the White- 
tailed Ptarmigan were available for 
study. It is doubtful whether in the diet 
 
timberline where the ground cover is 
generally scanty, consisting mostly of 
Carex and of a few small perennial 
herbs. Unless the Ptarmigans were 
driven from the mountain top into the 
timber by severe weather, there would 
be little chance of their finding hard 
seeds that could substitute for grit. 
HUNGARIAN PARTRIDGE 
(Perdix perdix) 
The Hungarian Partridge specimens 
used in this study were taken in south- 
eastern Washington during the hunting 
season. An examination of thirty-three 
gizzards failed to reveal any substitu- 
tion of hard seeds for grit. The food of 
the Partridge in this area seems to con- 
sist mainly of cultivated plants, as