192 THE ZOOLOGIST. 



1892 the immediate neighbourhood of two pairs of Ravens was found com- 

 patible with eighteen pairs of twin lambs safely delivered and all surviving. 

 The circumstance that an incoming tenant and a stock valuation made 

 every living lamb at that particular time worth a possible 15s. should stand 

 as a fairly practical test of my faith in the innocence of Ravens. Three 

 facts in this connection are not, I think, sufficiently considered. (1) The 

 rough-and-ready pathology of hill-sheep recognises no half-way house of 

 sickness, with possible convalescence, between health and death ; it must 

 be one thing or the other. A sick sheep on the hill is to all intents and 

 purposes a dead sheep, worth nothing but the fleece, at most the " braxy," 

 and a careful shepherd should always anticipate the scavengers to this 

 extent. The loss of an eye may add to the pangs of a dying animal, but it 

 takes nothing from the owner of the flock. (2) Hill-ewes lamb easily, 

 rapidly, and without assistance. Still-born lambs are rare, and ewes that 

 die in labour quite exceptional. The lamb is on its legs at once, and the 

 ewe's awakened instinct of maternity constitutes a safeguard which must be 

 seen to be believed. The stoop of the Golden Eagle at an unsuspected 

 moment I should conceive to be irresistible, though I have never seen it ; 

 but mother ewes are much too quick for the more deliberate Crows, which, 

 on all occasions when I have observed them, approach their quarry with 

 considerable circumspection. (3) The natural death-rate of a hill-flock 

 provides carrion enough and to spare for many scavengers. Taking the 

 distribution of sheep-ground in the Highlands at from three to eight acres 

 per sheep, and the normal death-rate of adult sheep — not counting hoggs 

 that die at winterings — at from 5 to 15 per cent, per annum, we get an 

 average carrion output of a dozen carcases per square mile per annum 

 thirty square miles giving a carcase for every day in the year, and this 

 without reckoning the death-rate of lambs from birth (April) to weaning 

 (August), which is understated at 10 per cent, for those four months alone. 

 The numbers actually exceed this calculation on many west-coast farms, 

 where a heavy death-rate follows in the wake of a heavy stock ; but in any 

 case Ravens need not kill their own meat, for nature keeps them constantly 

 supplied. Sometimes a rotting carcase prompts one to believe that the 

 supply is in excess of the demand. — Allan Gordon Cameron (Barcaldiue 

 Castle, Ledaig, N.B.) 



Larus ridibundus: Assumption of the Hood in Winter.— On Jan. 

 23rd last, a wild and boisterous day, with strong north-west wind and 

 driving showers of sleet and hail, large flights of Gulls were blown inland, 

 and were following the ploughs at work in the fields. Driving in the 

 neighbourhood of Wells, Norfolk, T noticed, amongst a flock largely composed 

 of Black-headed Gulls, one with an entirely black hood, which showed very 

 plainly against the falling snow. I am aware that this early assumption 

 of the breeding plumage has been observed at quite as early a date, but it 

 is by no means of common occurrence. — H. W. Feilden. 



