Long-tailed jaeger
Stercorarius longicaudus
Identification Tips:
- Sexes similar
- Small jaeger with long tail extension behind narrow-based wings
- Small bill with subtle gonydeal angle near midpoint of bill
- Mainly pelagic but occasionally seen inland
- Sometimes chases other birds to steal their food
- Powerful, yet agile, flight
- Juveniles take several years to reach adult plumage
- Light and dark color morphs
Adult light morph:
- Central tail feathers very elongated and pointed; longer than tail
- Black cap covers eye and crosses chin
- Yellow area below cap
- White nape
- Gray upperparts
- White underparts and dark undertail coverts
- Blackish outer wing and secondaries and gray inner wing; not as much
white on primaries as other jaegers
- Small, black bill
Adult dark morph:
- Central tail feathers very elongated and pointed
- Small, black bill
- Entirely dark plumage except for base of primaries
Juvenile:
- Rounded central tail feathers project pretty far beyond rest of tail
- Head, body, and wing linings barred-belly may be pale
- As birds age, gray of adult plumage becomes more apparent and tail
feathers lengthen
- Upperparts often with pale edgings
- Primaries dark with white shaft streaks on outer 2 primaries
- Often dark intrusion into white primary patch from below
- Axillaries and uppertail coverts strongly barred black and white
Subadult:
- Variable; gradually acquires adult plumage
- Occurs in both dark and light color morphs
- Best identified by tail feather shape, size, and bill shape
Similar species:
Young Long-tailed Jaegers look superficially like first-year Herring Gulls
but have a more powerful, direct flight and white patches on the primaries
visible from above and below the wing. Skuas are similar as well but are
bulkier and thicker-necked, with much more prominent wing patches. Jaegers
look most similar to each other. Adult Long-tailed can be safely identified
when their very long, pointed central tail feathers are seen. The adult
light morph Long-tailed lacks the breast band that Parasitic and Pomarines
have, and has gray, not dark brown upperparts contrasting with dark
secondaries. Juvenile and subadult jaegers are very difficult to
tell apart. The Pomarine has a heavier bill and is larger than the other
species and juveniles have very short rounded tail feathers. Juvenile
Parasitics often have distinctive cinnamon tones to their plumage, pale primary
tips or wavy uppertail coverts. Juvenile and subadult Long-tailed Jaegers
often look grayer than the other species and can have longer tails. Juvenile
Long-tailed Jaegers typically have black and white wavy uppertail covert bars
and axillaries, long rounded central tail feathers, just two white primary
shafts, and a dark intrusion into the white primary patch from below.