THE GUN AT HOME AND ABROAD 
and even hard frost, unless it is very severe, does not seem able to destroy 
their vitality. Before incubation commences the hen often adopts the pro- 
tective measure of covering up her eggs with grass or heather, which no 
doubt saves them from the effects of frost. Like other game-birds, the 
hen grouse, when sitting on the nest, is able to suppress all scent, and 
thus remains undetected. This fact, coupled with the marvellously pro- 
tective colour of the summer -plumage, must save many a bird from 
destruction by dogs and vermin. 
Incubation lasts for twenty -three or twenty -four days, and the young 
are able to leave the nest soon after they are hatched — ^being carefully 
tended by both parents. The hen, when menaced by danger, attempts 
to lead away the intruder by feigning a broken wing, and fluttering along 
the ground, while the young squat among the heather, their beautifully 
patterned down of buff and chestnut assimilating so closely with their 
surroundings that they are most difficult to find. 
Besides the many enemies which levy their toll on young grouse, such 
as foxes, stoats, and weasels, and their numerous feathered enemies in 
the shape of gulls, crows, etc., the chicks have to reckon with the ravages 
of a fatal disease now known as Coccidiosis, caused by an intestinal 
parasite {Eimeria avium). (See p. 58.) This disease attacks the chicks 
when they are quite young, and sometimes accounts for the disappearance 
of almost the whole of the stock. 
For the first few weeks the chicks subsist largely on insect food, though 
tender shoots of heather and blaeberry also form a part of their diet ; as 
they grow older they feed principally on heather. 
Though grouse feed more or less throughout the day, their principal 
feeding time is in the early morning and evening, when the crop is com- 
pletely filled. In the morning they are usually to be found on the lower 
grounds about the burns, but as the day advances they move to the higher 
broken ground and rocks, where they love to sun and dust themselves 
on the dry peaty banks. By creeping quietly up the cracks in the early 
morning, it is easy to get among the birds unobserved and watch the 
antics of the cocks as they spring a yard or two perpendicularly into the 
air and then drop to the ground, uttering their well-known crow, a-a-uck^ 
cucky Click, cuck, cuck, cuck, Click, err-ra. This is usually uttered on the 
ground, the bird standing nearly erect, especially towards the finish, 
when the tip of the tail touches the ground, the back of the neck and crop 
being considerably distended. The cock has numerous other calls, uttered 
54 
