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offspring, and will fly down close to an intruder, endeavouring to drive him off, besides using 

 every endeavour to decoy him away from the vicinity of its nest. Mr. Dunn {op. cit. p. 114) 

 says, " a dog I had with me on my first visit had been so repeatedly and severely struck by this 

 bird, that had he heard one cry, the sound of which from experience he was perfectly familiar 

 with, he would instantly come behind me for protection, and all my efforts to make him hunt 

 again were ineffectual until we had got some distance from the place ; another dog I had with 

 me on my second visit, possessing more courage than the former, after feeling the effects of their 

 bills and wings once or twice, and appearing much astonished at such a foe, would watch the 

 bird pouncing at him and spring from the ground to meet the attack ; and by this means he 

 escaped many severe blows." The nest of this Skua resembles that of the Black-headed Gull, 

 and is placed on the ground, or on a tuft of heather in open peat bogs ; and two eggs are 

 deposited. Like most of the Gulls, this Skua usually nests in larger or smaller colonies. 

 Dr. Saxby says (B. of Shetl. p. 360) that the breeding-grounds are " as often as possible in 

 elevated situations, the grassy tops of high cliffs projecting into the sea being preferred. The 

 nests are upon the ground, and in most cases are rather carelessly constructed, the materials 

 used being moss, short grass, and bits of heather. The eggs are laid during the latter part of 

 May, and, as was said in the case of the Great Skua, are apt to be very much darker in the early 

 part of the season. The most usual kind is a dark olive-green, slightly blotched and spotted 

 with dark brown, measuring two inches four lines by one inch eight lines. I have known an egg 

 three lines longer but of the same breadth — the shorter diameter of an egg being at all times, 

 and for all species, as far as my observations have gone, less liable to variation than the longer. 

 From a number of eggs brought me of this species on the 6th June, I selected the following 

 varieties, viz. : — very pale olive-green, without any marks ; olive-brown, so dark that the usual 

 brown marks could with difficulty be seeu ; greenish stone-colour, marked with brown and grey ; 

 clear dark olive-green, marked with olive-brown of several shades ; greenish grey, marked with 

 brown and brownish grey. Thus the diversity in the colouring must not be regarded as wholly 

 due to the degree of advancement of the season, all these being quite fresh when brought to me. 

 It may be remarked, by the way, that Shooies' eggs very soon spoil if not blown. I have 

 repeatedly noticed this." Mr. A. W. Johnson, who has visited the breeding-places of this bird 

 in Shetland, writes to me as follows : — " On the 31st May we took on Noss two clutches of two 

 eggs each and one single egg. The birds were extremely abundant here. On the 4th of June 

 we visited Mousa and found eight nests, most of them containing two eggs, nearly all incubated. 

 We also found a few more on the 5th on Noss. The two varieties appear to pair indiscriminately ; 

 but the dark birds are more abundant, I should think in the proportion of three to two. Their 

 cry resembles most nearly the mewing of a cat very much prolonged. When alarmed for the 

 safety of their nest they also utter a peculiar indescribable sound, between a hiss and a croak, 

 at the same time fluttering about, sometimes within a few yards of the intruder, endeavouring to 

 lead him to a safe distance from their nest, and then take to flight with what seems to be an 

 exultant scream. Their power of flight is remarkable, and is best observed when a strange bird 

 is pursued by the owners of a nest he has incautiously approached. It is then very beautiful to 

 see the evolutions they perform, now swooping down close to the ground, then rising almost 

 perpendicularly to a considerable height, and then sweeping along with such speed that as they 



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