426 BRITISH BIRDS. 
The food of the Ptarmigan is almost exclusively composed of vegetable 
substances, such as the seeds, buds, and tender shoots of mountain-plants, 
especially the heath and ling. This fare is varied in autumn with berries 
of various kinds and ground-fruit. Macgillivray says that the Ptarmigan 
picks up a quantity of quartz to aid in the digestion of its food, and that 
it breaks off the twigs or picks the buds and shoots until it has accumu- 
lated a large quantity, just like a grazing animal, and then goes off to a 
suitable spot to rest and slowly digest the food it has gathered. 
Ptarmigan pair very early in the spring, and each couple retire to seek 
a nesting-place. The nest is very slight, and consists of a little hollow, 
either scratched out by the bird, or a ready-formed depression in the soil, 
which is lined with a few twigs, a little withered grass, and sometimes a 
few feathers that probably drop from the parent’s plumage. In this 
scanty nest the female deposits from eight to ten or even twelve eggs, 
which are usually laid early in May, but sometimes not until the end of that 
month if the season be backward. They vary in ground-colour from dirty 
white to rich brownish buff, and are spotted, speckled, and blotched with 
rich chocolate-brown. All the markings are on the surface, no grey under- 
lying ones being traceable; the spots and blotches only vary in intensity of 
colour, the largest being generally the darkest. They vary in length from 
1:8 to 1:65 inch, and in breadth from 1:26 to 1:15 inch. The eggs of the 
Ptarmigan may generally be distingwshed from those of the Red Grouse 
by their much buffer ground-colour, which is all the more conspicuous from 
the eggs being less profusely spotted. The female Ptarmigan does not sit 
very closely, as if well aware that her eggs will receive protection from 
their colour in her absence. The young birds are able to run about and 
follow their parents as soon as they leave the shell, and even at such an 
early period of their lives are well able to escape from enemies. When 
menaced by danger the old birds will often flutter along the ground in an 
excited way, and the brood scatters, each little chick making off to some 
~ convenient place, where it remains, motionless as the stones amongst which 
it is crouched, until the cause of alarm has gone. 
Ptarmigan gather into flocks much earlier than Red Grouse, often as 
soon as the end of July. During the greater part of the year these 
flocks reside on the highest parts of the mountains; but in winter, espe- 
cially in very stormy weather, they come lower down the hill-sides, 
Although these flocks are very wary, they often allow the sportsman or the 
shepherd to come close to them ere they take wing. When alarmed 
they often fly from the particular haunt from which they were disturbed, 
and cross the intervening valley to another mountain-top, perhaps more 
than a mile away. They fly in a scattered manner, and do not rise en 
masse, but one or two at a time, to the no small astonishment of the 
observer, who cannot detect a single bird until they rise almost at his feet, 
