SABINE'S GULL. 299 



with the Arctic Tern, and describes the eggs as two in number, but states 

 that they were placed on the bare ground ; he also describes the great 

 anxiety of the parent birds at the nest. MacFarlane obtained eggs of this 

 bird from an island in a lake on a promontory stretching out into the 

 Arctic Ocean, east of the Mackenzie river, in June, and states that the eggs 

 were occasionally three in number. Richardson found it breeding on an 

 island in the Arctic Ocean a few miles to the west of MacFarlane's locality, 

 and states that the eggs were deposited in hollows in the short and mossy 

 turf. 



The eggs of Sabine's Gull vary in ground-colour from pale brown to 

 dark brown, occasionally approaching olive-brown. The spots are small, 

 varying from the size of a pea downwards, and are generally somewhat 

 indistinct and sparingly but evenly distributed. The surface-spots are 

 darkish brown, and the underlying spots are greyish brown but very 

 indistinct. Occasionally one or two almost black spots or streaks are 

 found, principally at the large end of the egg. They vary in length from 

 1'8 to 1*7 inch, and in breadth from 1/3 to 1*2 inch. In colour the eggs 

 of this bird most nearly resemble Skua's eggs, but are much too small to 

 be confused with any of them. 



Adams, who met with Sabine's Gull in Alaska, states that it feeds upon 

 worms and insects ; Middendorff found the stomachs both of the old and 

 young filled with the larvee of a dipterous insect ; but Sabine asserts that 

 it obtains its food on the beach near the water's edge, picking up the 

 marine insects that are cast on the shore. 



The Black-headed Gulls form a small group, which resemble the Terns 

 in having a black head during the breeding-season; and Sabine's Gull 

 presents another point of affinity with that genus in having a forked tail, 

 the outside feathers being an inch longer than the central ones. It is one 

 of the smallest species of the genus. The adult in breeding-plumage has 

 a dark slate-grey head and nape, emphasized by a narrow black collar round 

 the neck, which is pure white below it. The rest of the plumage is typical 

 Gull- colour i. e. mantle, scapulars, and most of the wing-coverts French 

 grey ; upper tail-coverts, tail, and underparts white ; quills black, marked 

 with white on the tips and on the outer half of the inner webs. Bill 

 black, vermilion at the tip * ; legs and feet bluish black ; orbits carmine ; 

 irides hazel. After the autumn moult the dark hood disappears, but the 

 back of the neck has become a dark slate-grey ; it is possible, however, 

 that the latter character may be the remains of immature plumage. 



* Gould, Dresser, Saunders, and Baird, Brewer and Ridgway describe the bill of Sabine'a 

 Gull as black, with a yellow tip. This is probably the colour in the dried skin. Midden- 

 dorft' expressly states that Gould's figure is wrong, that in the living bird the colours are 

 very brilliant, the tip of the upper mandible being vermilion and that of the lower man- 

 dible paler vermilion, approaching lemon-colour. 



