Verification of Unusual Sight Record
For Utah

Rec. # 2020-02

Common name:

Parasitic Jaeger

Scientific name: Stercorarius parasiticus
Date: 09-21-2014
Time: 9:45amish
Length of time observed: 15 minutes
Number: 1
Age: Juvenile
Sex:  ?
Location: Antelope Island Causeway, 2nd bridge
County: Davis
Elevation: 4200ft
Distance to bird: 50-200m
Optical equipment: 10x50 Nikon Binos, Canon SX50 Digital Camera
Weather: Raining and overcast
Light Conditions: Overcast made flat light, if it had been sunny the bird likly would have been backlit
Description:        Size of bird: 16in
(Description:)       Basic Shape: Gull like
(Description:)  Overall Pattern: Overall uniformly rusty brown
(Description:)            Bill Type:  
Field Marks and
Identifying Characteristics:
"Medium sized Jaeger flew over the AIC very close, near the 2nd bridge. Landed out in the lake to the south a couple hundred yards out. We watched it in the scopes for over 10 minutes. Medium sized gull like bird, not small enough to be a Long-tailed, bill not massive enough to be a Pomarine. Observed in a long chase with a gull.White crescent in primary base (on upper side) noted, as was whitish base to tail. Apparent immature intermediate morph" From notes taken at time of sighting. After consulting references and looking at photos online, I think the bill size and shape shown in the photo best fit a Parasitic, specifically it has a small nail on a long bill.
(see photos)
Song or call & method of delivery: None heard
Behavior: Chasing gulls near the bridge
Habitat: Open water of Great Salt Lake, mostly observed over brackish water of Farmington Bay
Similar species and how
were they eliminated:
Long-tailed Jaeger-Smaller with a longer tail and more delicate build and showing white in only P8 and P9 primaries at base on upperside, shorter bill with larger nail in proportion. More buoyant and graceful flight style, not as fast aggressive and falcon like as this bird was. Dark and intermediate morphs rare

Pomarine Jaeger-Larger and more massive with a broader chest and short tail, nail on bill more massive and prominent than this birds
Previous experience with
this & similar species:
This was my 1st Jaeger, but have seen 4 since, 3 Parasitic and 1 Long-tailed
References consulted: Sibley, eBird.
Description from: Notes taken at the time of the sighting
From photo(s) taken at the time of the sighting
Observer: Bryant Olsen
Observer's address: 688 East 700 South #105
Observer's e-mail address: **
Other observers who independently identified this bird: Kendal Watkins, Norm and Gail Jensen and BIlly Fenimore were with me
Date prepared: 1-3-2020
Additional material: Photos
Additional comments: eBird checklist: Photo taken by Norm Jensen, used with permission.