Verification of Unusual
Rec. # 2007-34
|Scientific name:||Stercorarius longicaudus|
|Date:||10-18-07 (has remained through 10-21-07|
|Time:||11:30 without optics, and studied and took notes and photos later that afternoon 15:00 - 18:00 hrs|
|Length of time observed:||Observed: 2-3 hours over several days|
|Location:||Quail Creek State Park|
|Elevation:||~ 900 m|
|Distance to bird:||50 - 1000 m|
|Optical equipment:||Ziess 85 T Diascope|
|Light Conditions:||shade and full sun, front lit, backlit, overhead, etc.|
|Description: Size of bird:|
|(Description:) Basic Shape:|
|(Description:) Overall Pattern:|
|(Description:) Bill Type:|
Field Marks and
Overall coloration: black, dark brown, and grayish tones. Thin and delicately
shaped with long narrow wings, long tail, smallish rounded head and small bill.
Tail length clearly longer than width of wings.
In Flight: small graceful, very reminiscent of a Sabine's Gull, Bonaparte's Gull, or an Arctic Tern in flight, with a boyant, easy flight style, often soaring and circling, and dropping down to the water surface, where it would paddle briefly and/or peck at the surface. Relatively shallow wing beats, with only the wrist outwards appearing to bend below the plane of the body.
Upper wings in flight: Noticeable contrast on upper surface of wings with darker (blackish) primaries and secondaries and lighter (dark gray) upper wing coverts. In close view, the outer two primaries with distinct and bold white shafts, and from a distance, these outer white
primary shafts appeared as thin white band inside the leading edge of the wing.
Under side of wings and body in flight: Long narrow wings with very dark primary tips and distinct white patch at the base of primaries appearing as an obvious white crescent. The under wing coverts with bold black and white vermiculations extending to sides, flanks, and undertail
coverts. Upper parts were overall dark with distinct pale rump (uppertail coverts) with black and white banding noticeable at close range. Tail wedge-shaped with dark tip and two long, tapering, squared center rectrices extending well beyond the rest of tail. Belly, chest, throat, head, and nape pale tan/ grayish white, with top of head and upper chest appearing slightly darker at certain angles.
Perched: When perched on the water the jaeger set very high with head up and tail and wings pointed up at 30 to 45 degree angle. Head round and pale with whitish nape and slightly darker area at the top of head, throat, and across the upper chest, appearing as an indistinct darker
cap and breastband at some lighting angles. Wings long with distinct white barring across the upper coverts, secondaries, and tertials, very dark primaries without noticeable pale tips. Under side of tail with very prominent bold black and white banding (visible from a long distance).
Finer black and white barring extending along flanks and sides below the wing. Eye dark, and bill short and relatively thick, pale at base with a dark tip (nail).
|Song or call & method of delivery:||none|
In Flight: small graceful, very reminiscent of a Sabine's Gull, Bonaparte's
Gull, or an Arctic Tern in flight, with a boyant, easy flight style, often
soaring and circling, and dropping down to the
water surface, where it would paddle briefly and/or peck at the surface. Relatively shallow wing beats, with only the wrist outwards appearing to bend below the plane of the body.
were they eliminated:
Distinguished from larger jaegers by overall small and delicate size and
structure and light bouyant flight style.
Juvenile light Parasitic Jaegers can be similiar however typically larger with darker heads, chest, and upper breast, overall more brown or rufous tones (rather than black, gray, and white), longer more slender bill, distinct pale tips on primaries, outer primaries with 3-4 white shafts (rather than 2), more uniform upperwing coloration, less distinctly barred underwing coverts, lack bold black and white undertail covert barring, broader wings, shorter tail, and shorter central tail rectrices.
this & similar species:
|Limited experience with Long-tailed Jaegers, however I've viewed juvenile LT Jaegers a few times, most recently Sept 06 in Monterey Bay. More experienced with other jaeger species.|
|References consulted:||Sibley Guide to Birds|
|Description from:||Notes taken at time of sighting|
|Observer's address:||3505 West 290 North, Hurricane, UT, 84737|
|Observer's e-mail address:||email@example.com|
|Other observers who independently identified this bird:||Fortunately the jaeger stuck around and many additional observers viewed the bird.|
|Additional Comments:||Most photos taken through Ziess scope with Olympus Camedia 10x camera, others with Nikon D80 (300 mm Nikkor lens).|