Verification of Unusual
Sight Record
For Utah
Rec. # 2021-51
| Common name: |
Long-tailed Jaeger |
| Scientific name: | Stercorarius longicaudus |
| Date: | 8/30/2017 |
| Time: | 12:00pm |
| Length of time observed: | 8 minutes |
| Number: | 1 |
| Age: | juvenile |
| Sex: | ? |
| Location: | Antelope Island Causeway |
| County: | Davis |
| Latilong: | 41.087363, -112.195280 |
| Elevation: | 4200ft |
| Distance to bird: | 50m at closest |
| Optical equipment: | Nikon 10 X 42 Binoculars |
| Weather: | Sunny, hot and calm |
| Light Conditions: | Good |
| Description: Size of bird: | Flying, no frame of referrance |
| (Description:) Basic Shape: | Gull like |
| (Description:) Overall Pattern: | overall blackish |
| (Description:) Bill Type: | long and thin |
|
(Description:)
Field Marks and Identifying Characteristics: |
This Jaeger was a hard lesson in the trouble of juvenile Jaeger ID. Its so easy
to get false impressions of size from flying birds, and the dark color made it
seem larger than it was. Juvenile dark morph. Very blackish overall, but some
white feather edging on underwings and rump, black and white banding on
undertail coverts, white shafts restricted to P10 and P9. Long narrow pointed
wings and long tail with long R1 tail feathers. Overall tern like structure of a
Long-tailed Jaeger. Timing also favors Long-tailed. I submitted photos of this bird to both the Facebook Advanced Bird ID and later Skuas and Jaegers of the World groups and heard independently from multiple sources that Long-tailed Jaeger was the best match. (see photos) |
| Song or call & method of delivery: | None heard |
| Behavior: | Flying fast and low over dry lake bed then flew over and followed causeway, then turned NW and flew over marina and out over the lake, always at top speed. |
| Habitat: | Playa and saltwater of Great Salt Lake |
| Similar
species and
how were they eliminated: |
Pomarine Jaeger-Larger, deep pot bellied look,
broad based wings, white shafts on 5 to 7 upper wing primaries, underwing double
flash not seen on this bird. Short tail and R1 tail feather Parasitic Jaeger-White shafts on 5 upper wing primaries, usually rusty or all dark undertail coverts, shorter R1 tail feathers. |
| Previous
experience with this & similar species: |
I had seen 1 Long-tailed Jaeger, also a juvenile, on 9/27/2014 in the same location(AIC). Since then I have seen many Long-tailed Jaegers in Alaska last month(adult and juvenile) and one in Washington State(adult). I have also seen many of both Parasitic and Pomerine Jaeger |
| References consulted: | Sibley, Macaulay Library Photos, Facebook Advanced Bird ID and Skuas and Jaegers of the World groups |
| Description from: | From photo(s) taken at the time of the sighting |
| Observer: | Bryant Olsen |
| Observer's address: | 84102 |
| Observer's e-mail address: | ** |
| Other observers who independently identified this bird: | Charles Hurd and Lauri Taylor were with me |
| Date prepared: | 9/7/2021 |
| Additional material: | Photos |
| Additional comments: | eBird checklist: https://ebird.org/checklist/S38911523 |