Two subspecies currently recognized:
S. l. longicaudus
S. l. pallescens

Also known as Long-tailed Skua
 

Identification

Figure 1 Very dark juvenile Long-tailed Jaeger. Composite figure of a single bird videotaped at sea NW of Bodega Head, California on 25 August 1999 during a Shearwater Journeys trip. Copyright of Angus Wilson© 1999
 

Where and When

Photographs on the web

A superb series of birds photographed by Tony Palliser in February off Wollongong, NSW, Australia:
Adult/subadult in basic plumage showing breast band and uppersurface of wings and tail.
Immature taking flight showing uppersurface of wing, lacking obvious wing flash
same immature taking flight showing detail stripes on underwing
Close-up of an immature(?), showing details of the mantle and striped uppertail coverts.

Sideview of adult in flight Photographed in October off the Santa Lucia Escarpment, California by Jerry R. Oldenettel.

A very nice series showing multiple individuals in basic plumage feeding on a floating log. Taken by Martin Reid off Chile in December.

Breeding adult Photo taken in Finland by Markku Savela

Adult in alternate plumage Portrait taken in Churchill, Manitoba, Canada by Simon Perkins.

Adult in alternate plumage flying Photograph by Monte Taylor, taken in Barrow Alaska.
 
 

Literature

Kitson, AR. (1979) Separation of adult pale-phase Arctic and Long-tailed Skuas. BRITISH BIRDS 72(3): p120-121.

van IJzendoorn, EJ and de Heer, P. (1981) On identification of immature Arctic and long-tailed skua. DUTCH BIRDING 3(1) 1981: 10-12.

Olsen, KM. and Christensen-S. (1984) Field identification of juvenile skuas. BRITISH BIRDS 77(9): p448-450.

Norman, DM. (1985) A white-headed juvenile Long-tailed Skua. BRITISH BIRDS 78(9) 1985: 453-454.

Stawarczyk, T. (1986) Identification of skuas in juvenile and post-nuptial plumages. NOTATKI ORNITOLOGICZNE 26(3-4): p177-191.

Olsen, KM. (1986) [Young skuas can be identified.] FUGLE 6(4) 1986: 13-15.

Johnson, DP. (1986) Jaeger identification. LOON 58(3) 1986: p141-142.

Malling Olsen, K. (1987) Identifying juveniles of the smaller skuas. in Grant, P.J., Sharrock, J.T.R., Taggar, S. & Shirihai, H. International bird identification. Proceedings of the 4th International Identification Meeting Eilat 1st - 8th November 1986. International Birdwatching Centre Eilat, P.O.B. 774 Eilat, Israel. 1987.

Melville, DS. (1985) Long-tailed Skuas Stercorarius longicaudus in New Zealand. NOTORNIS 32(1) 1985: 51-73.

van der Elst, D. (1987) A propos de l'identification du labbe a longue queue (Stercorarius longicaudus) juvenile. AVES 24(3): p112-119.

Turner, JE. (1987) Flight identification of skuas. HILBRE BIRD OBSERVATORY REPORT 1987 1987: 46-49.

de Fraine, R. and Leysen, K. (1988) Identification of a first year long-tailed skua. ORIOLUS 54(4): p162-165.

Malling Olson, K and Jonsson, L. (1989) Field identification of the smaller skuas. BRITISH BIRDS 82(4): p143-176.

Butler, A. and McLoughlin, J. (1989) Identification of a dark juvenile long-tailed skua. BIRDING WORLD 2(10) 1989: 362-364.

Ullman, M. (1990) Long-tailed skua identification. BIRDING WORLD 3(1): p28-29.

van den Berg, AB. (1991) Mystery photographs. DUTCH BIRDING 13(3): p106-108.

Hardwick, M. (1993) A long-tailed skua with extensive white wing flashes. BIRDING WORLD 6(10): p403-404.