The long-tailed Jæger is, according to length, the largest of the Jægers, being 21 in. long; this is, however, due to the long sharp pointed central pair of tail feathers, which extend about eight inches beyond the others, and from the most noticeable distinguishing point from the former species. The plumages that have been described are the light phases; all the Jægers have a dark phase in which the plumage is a nearly uniform sooty brown, lightest below. The Long-tailed Jægers are the most numerous in Alaska and are even more graceful in flight than are the Gulls and Terns, floating, skimming, sailing, plunging, and darting about with incredible swiftness and ease. Like the others of this family, they pilfer their food from the Gulls, and are also very destructive to young birds and eggs. Their eggs are either laid on the bare ground or in a slight depression, scantily lined with grasses. The eggs are indistinguishable from those of the preceding species except that they average a trifle smaller. Size 2.10 × 1.50. [Illustration 039: Brownish.] [Illustration: Parastic Jæger. Long-tailed Jæger.] [Illustration: Olive brown.] [Illustration: right hand margin.] Page 38 GULLS and TERNS. Family LARIDÆ Gulls are webbed footed birds having a slight hook to the end of the upper mandible. Their plumage is generally a silvery gray above and white below. They nest in large colonies, some on the islands of fresh water inland, but mostly on the sea coast. They procure their food from the surface of the water, it consisting mostly of dead fish and refuse matter, and crustacea which they gather from the waters edge. When tired they rest upon the surface of the water, where they ride the largest waves in perfect safety. Terns are birds of similar plumage to the Gulls, but their forms are less robust and the bills are generally longer and sharply pointed. Their food consists chiefly of small fish which they secure by hovering above the water, and then plunging upon them. They are less often seen on the surface of the water than are the Gulls. [Illustration 040: Walter Raine. CHARACTERISTIC NEST OF A LOON.] [Illustration: Left hand margin.] Page 39 39. IVORY GULL. _Pagophila alba._ Range.--Arctic regions; south in winter to the northern border of the United States. The little Snow Gull, as it is often called, is eighteen inches in length. In the breeding season the plumage is entirely white; the bill is tipped with yellow and there is a red ring around the eye. These Gulls nest in large colonies in the Arctic Regions, placing their nests on the high rocky cliffs. The nest is made of grass, moss and rubbish, and the three eggs are laid during June. The eggs are olive color and the markings are dark brown. 40. KITTIWAKE. _Rissa tridactyla trydactyla._ Range.--North Atlantic and Arctic regions, breeding from the Gulf of the St. Lawrence northward and wintering south to the Great Lakes and Long Island.