perceiving a distant flock of Gulls, he rises on wing and speeds towards
them. Renewing his attacks, he now obtains an abundant supply, and at
length, when quite gorged, searches for a place on which to alight, unseen
by any other of his tribe more powerful than himself. When on wing, its
beautiful long tail-feathers seem at times to afford this bird great assistance
in executing short sudden turns, which have often brought to my mind the
motions of a greyhound while pursuing a hare. By sudden lashings of its
tail, it can instantly turn, or arrest its flight. When it is on the water, it
keeps that part upright, but when on a rock or a floating piece of timber, it
allows it to fall in a graceful manner.
Although usually seen single, or at most in pairs, during the winter, I observed this species in April, on my voyage to the Florida Keys, in flocks of from ten to fifteen, congregated as if for the purpose of returning to the northern regions, where it is said to breed in groups. Mr. Selby, in treating of this bird, says "It breeds upon several of the Orkney and Shetland Isles, and is gregarious during that period; and the situations selected for nidification are the unfrequented heaths at some distance from the shores. The nest is composed of dry grass and mosses, and its two eggs are of a dark oil-green, with irregular blotches of liver-brown. At this season the bird is very courageous, and, like the Common Skua, attacks every intruder upon the limits of its territory, by pouncing and striking at the head with its bill and wings. It also occasionally endeavours to divert attention by feigning accidental lameness." Having received eggs of this bird from individuals who had collected them, I may add that they are broadly rounded at the larger end, rather pointed at the smaller, have a smooth shell, and average two inches four-twelfths in length, by one inch and four and a half eighths in breadth.-
M. Temmixck, in his Manuel d'Ornithologie, describes the young when about to leave the nest as follows: "Top of the head of a deep grey; sides and upper part of the neck of a light grey, sprinkled with longitudinal brown spots; a black spot before the eyes; lower part of the neck, back, scapulars, small and large wing-coverts, umber-brown, each feather bordered with yellowish-brown, and often with reddish; lower parts irregularly variegated with deep brown and yellowish-brown on a whitish ground; tail-coverts and abdomen transversely barred; quills of the wings and tail blackish, white at their base and on the inner barbs, all terminated with white; the two outer shafts white; tail only rounded; base of the bill yellowish-green, black towards the point; tarsi bluish-grey; base of the toes and membranes white, the rest black, hind claw often white."
In middle age, he says, "all the upper parts are greyish-brown without spots; lower parts of a somewhat lighter tint, and also unspotted; inner base Vol. VII. 28
