THE WEIGHT OF GROUSE 133 



are abundant. Heather seed - heads are eaten in preference to the shoots 

 until, in January, the seeds are shed, and then the birds again fall back 

 on the winter heather shoots. It might be expected that the weight of 

 Grouse would suffer from the shortage of nourishment contained in the winter 

 food : but, as a matter of fact, the average weight of both sexes gradually 

 increases during the winter months until March, the worst and most trying 

 month of the whole year for Grouse. February, March, and April must be 

 considered months of greater or less starvation every year, since the winter 

 food has been picked over, not only by the Grouse themselves, but by cattle, 

 sheep, deer, and hares, and often, too, the whole moor has long been buried 

 deep in snow, or the heather has suffered badly from frost or from the dry 

 parching effect of north-east winds. Sometimes the roots have been frozen in 

 the surface soil, and the soil has been too cold to allow even a drain of sap 

 to rise, so that the Grouse are hard set to find food enough to maintain their 

 weight. Although the hen appears able to remain in good condition, the 

 cock always loses weight to some extent at this time often far too much 

 and in consequence suffers from a diminished power of resistance to Entozoa. 

 When thus half-starved, and long before he has any chance of recuperation, 

 the exhausting necessities of courtship force themselves upon him. 



The cock bird in February is still in full winter plumage, and by March, 

 though he possesses well-developed supraorbital combs, these alone of all his 

 attractions can be considered a special addition to his winter dress for courtship. 

 These crests or combs over the eyes are erectile organs of a brilliant crimson 

 colour, and inconspicuous or even invisible as they are when the bird is at 

 rest, they become in excitement so erect and tense as almost to meet above 

 the top of the head. They are then visible from afar, and are indica- 

 tions of the nervous tension of the breeding season. The bird is at this 

 time bold, noisy, aggressive, jealous, excitable, pugnacious, and magnificent 

 to see. He struts, becks, flies constantly about from one hillock to another, 

 defies all comers, fights viciously, eats little, and constantly attends his mate. 



Throughout February and March he leads this exhilarated but exhausting 

 and unsettled life, constantly at war, and daily becoming more and more 

 reduced in weight. In addition to all this, he is probably loaded up with 

 parasites, and, though he may live to recover, the strain is often too great, 

 with the result that it is in April and May that the majority of cock birds 

 die of disease. 



