76 MIGRATORY BIRDS. 



credit. And that the head of the bird, as Nilsson states, 

 should at sucli times be above the surface of the snow, 

 also seems to me very strange. Scores of times, when 

 crossing' glades and other openings in the forest, -where 

 the surface of the snow, to the casual observer at least, 

 appeared to be smooth as glass, one or more Black-Cocks 

 liave suddenly emerged from beneath the snow almost at 

 my feet ; and when, expecting every moment others to 

 follow, I have carefully looked about me, I never could 

 discover anything beyond the slightest indentation in the 

 snow where the bird had burrowed, the hole itself being 

 filled up by the sides collapsing ; and yet, perhaps within 

 the next minute, half a score more Black-Cocks would 

 fly up all around me. That their heads were above the 

 surface previously to their leaving the snoM' I hold to be 

 utterly impossible, nor can I conceive that even their 

 beaks protruded, as others will have it. If air be needful 

 to birds when thus embedded in the snow, their breath, 

 no doubt, forms an almost imperceptible orifice, through 

 which they are enabled to respire. 



The fact of birds thus burrowing into the snow has 

 been known from time immemorial. Nor did it escape 

 the notice of the learned Bishop Pontoppidan, who, 

 though he at times deals somewhat in the marvellous, is 

 generally pretty correct in the main. 



•' In the winter time," so he writes in his usual quaint 

 wav, " the Black-Grouse take care of themselves in this 

 manner : they first fill their craw with as much food as 

 it will hold, so that it hangs like a bag under their necks, 

 whereby they are provided with something to live on for 

 some time ; then they'll drop themselves down into the 

 soft snow, and don't stay in their first hole, but undermine 

 and burrow in the snow some fathoms from it ; and there 

 they make a small opening for their bills, and thus lie 

 warm and comfortable." 



