LIFE HISTORIES OP NORTH AMERICAN GULLS AND TERNS. 3 



short and rounded, the quills having very different proportional length from 

 those of adults; second longest, third but little shorter, first about equal to 

 fourth. The inner or longest secondaries reach, when the wing is folded, to 

 within an inch or so of tip of longest primary. Central rectrices a little shorter 

 than the next. Colors generally as in adult, but duller and more blended, 

 having few or no white spots ; reddish spots dull, numerous, and large, espe- 

 cially along edge of forearm and on least and lesser coverts. On underparts 

 the colors lighter, duller, and more blended than above; prevailing tint light 

 dull rufous, most marked on abdomen, but there and elsewhere more or less 

 obscured with ashy or plumbeous. Remiges and rectrices dull brownish-black ; 

 their shafts yellowish-white, darker terminally. At bases of primaries there 

 exists the ordinary large white space, but it is more restricted than in adults, 

 and so much hidden by the bastard quills that it is hardly apparent on outside 

 of wing, though conspicuous underneath. 



Young birds may become indistinguishable from adults at the first 

 postnuptial molt, when a little over a year old, but perhaps not for 

 a year or two later. 



Adults seem to have but one complete molt — the postnuptial-^in 

 August. Adults can be distinguished by their larger size and by the 

 elongated feathers of the neck with the whitish central streaks. 



Food. — Yarrell (1871) writes of the food of the skua: 



Their food is fish, but they devour also the smaller water birds and their 

 eggs, the flesh of whales, as well as other carrion, and are observed to tear their 

 prey to pieces while holding it under their crooked talons. They rarely take 

 the trouble to fish for themselves, but, watching the smaller gulls and terns 

 while thus employed, they no sooner observe one to have been successful than 

 they immediately give chase, pursuing it with fury; and having obliged it 

 from fright to disgorge the recently swallowed fish, they descend to catch it, 

 being frequently so rapid and certain in their movements and aim as to seize 

 their prize before it reaches the water. The stomachs of a pair which were 

 shot were full of the flesh of the kittiwake, and the castings consisted of. the 

 bones and feathers of that small gull. Heysham has noticed an adult female 

 on the coast of Cumberland, which allowed herself to be seized while she was 

 in the act of killing a herring gull. It also feeds on fish offal, and the editor 

 found by the side of a nestling some disgorged but otherwise uninjured 

 herrings of large size. 



Behavior. — In appearance as well as in habits the skua seems to 

 share the attributes of the Raptores and the Laridae; its strong, 

 hooked bill and its sharp, curved claws enable it to stand upon and 

 rend asunder the victims of its rapacious habits. Its flight is also 

 somewhat hawk like. Yet it stands horizontally, and runs about 

 nimbly like a gull. Morris (1903) says that.it "soars at times at a 

 great height, and flies both strongly and rapidly, in an impetuous, 

 dashing manner." Mr. Walter H. Rich has sent me the following 

 notes on the flight of this species : 



When on the wing, -which is the greater part of the time, the skua shows 

 in the air hawk like, rather than like the gulls, with whom we rather expect 



