144 HILL BIRDS OF SCOTLAND 



mother Grouse does not brood on them, contenting herself 

 with watching them closely till the dipping of the sun 

 on the horizon. In cold weather she broods them almost 

 as closely as she did her eggs, for the chicks are very sus- 

 ceptible to a keen wind, and commence to shiver violently 

 and to seek out any shelter there is handy witliin a few 

 minutes of their mother leaving them. Grouse with 

 young vary greatly in their behaviour when disturbed. 

 The cock is usually near the hen, and both birds may fly 

 off so unconcernedly that they might well have no children 

 in danger. More often, however, the cock Grouse flies 

 right away, while his mate flops and flounders over the 

 heather in her attempt to decoy the intruder from the 

 whereabouts of her family. Sometimes I have found it 

 possible to call her up almost to my feet by imitating the 

 alarm cry of a young Grouse in distress, but this ruse is 

 not usually so successful as it is with the Ptarmigan. 



The rate of growth of a young Grouse is rapid, es- 

 pecially if the weather be favourable. On the third day 

 the primaries and secondaries commence to appear, and 

 by the ninth are well developed. During the first weeks 

 of their lives the young birds feed on insects — flies, beetles, 

 caterpillars — later they eat heather shoots and the tender 

 stems and leaves of the blaeberry {Vaccinium myrtillus). 

 I have seen young birds strong on the wing on June 6th, 

 at a date when some of the Grouse on the higher beats 

 had scarcely commenced to brood. During their youth 

 Grouse at times suffer severely from the attacks of a 

 minute unicellular organism, by name Eimeria avium. 

 This parasite is unintentionally picked up by the bird with 

 its food or water, and destroys the intestines of its host. 

 As this illness, or coccidiosis, as it is termed, is highly 

 infectious, it is important that the dead chicks be burnt 

 whenever possible. Coccidiosis, it must be borne in mind, 

 is a malady totally distinct from the so-called Grouse 



