Long-tailed Jaeger

Status Rare transient. The paucity of available records suggests that this jaeger occurs off our shores less frequently than the two preceding species. Chamberlain (1891) says it is common in the Bay of Fundy during spring and fall, but subsequent observations do not bear this out. Six immature specimens in the American Museum of Natural History were taken near Sable Island on 15 August 1896. Allen (1916) recorded an immature specimen from the vicinity of Yarmouth taken late in summer 1910. Recent records from Sable Island were of two harrying some terns on 9 June 1968, one on 12 June 1977 and two on 4 June 1979. There are only five other reports of individuals: 19 May 1978 in the Northumberland Strait; 10 September 1979 on Georges Bank; 30 April 1980 near Seal Island; 30 May 1979 on the Scotian Shelf about 170 km south of Halifax; and 10 November 1980 off Brier Island. In the last two cases, and perhaps in some of the others, the identification was by no means certain.

Description Length: 50-58 cm, including the long tail streamers. Only one (light) colour morph usually occurs in this species, though dark birds are known. In colouration, it is hardly distinguishable from the two preceding jaegers (see Pomarine Jaeger for description). Decidedly smaller than the Pomarine; slightly smaller and lighter in build than the Parasitic. The very long tail feathers of the adult are narrow and attenuated, instead of broad and twisted as in the Pomarine, and project well beyond the tail, instead of only a little way as in the Parasitic. Unfortunately, these feathers are often broken or missing in birds seen in autumn. The white wing-flashes are poorly developed in this species, and breeding light-morph birds never have a dark band across the breast. Legs bluish gray; toes webbed.

Range Circumpolar. In North America, breeds from Alaska to Greenland and south to the northern Ungava Peninsula. Winters off the coasts of the southern United States and South America.

Remarks The breeding of the Long-tailed Jaeger on arctic tundra is closely related to the abundance of lemmings and mice, its principal summer food. These rodents undergo regular cycles of abundance and scarcity, and in years of scarcity the jaegers often do not breed at all.