Verification of Unusual Sight Record
For Utah

Rec. # 2020-01

Common name:

Parasitic Jaeger

Scientific name: Stercorarius parasiticus
Date: 10-5-2014
Time: 07:15am
Length of time observed: 15 minutes
Number: 2
Age: Juvenile and adult
Sex: ?
Location: Antelope Island Causeway, 2nd bridge
County: Davis
Elevation: 4200ft
Distance to bird: 50m at closest approach
Optical equipment: 10x50 Nikon Binos, Canon SX50 Digital Camera
Weather: Mostly sunny
Light Conditions: Good
Description:        Size of bird: 16in
(Description:)       Basic Shape: Gull like
(Description:)  Overall Pattern: overall dark but with paler belly
(Description:)            Bill Type:  
Field Marks and
Identifying Characteristics:
"Continuing adult and juvenile(both apparent light morphs) from yesterday. I saw the adult just before dawn, around 7am, flying north of the 2nd bridge a few hundred meters out. Very distinctive flight,fast and low just above the water. All blackish-brown upper-side,under-wings and cap, bright white belly. Long pointed R1 tail feathers. It flew around for about 5 minutes,coming in to about 200m out, then flew southeast until I lost it. About 1/2 hour later, another Jaerger was seen at the 2nd bridge, but this was more mottled brown so it was a juvy. It flew much closer,chasing and harassing gulls, very fast falcon like flight." From my notes taken at the time of the sighting. I did not find either of these Jaegers, I was just chasing reports that had come over the eBird rare bird alerts. That fall there were at least 4 different Jaegers that had been seen near the 2nd bridge of the AIC
(see photos)
Song or call & method of delivery: none heard
Behavior: Adult, seen flying over causeway heading north, landed briefly on the water but immediately got up and then circled back around heading SE toward Farmington bay

Juvenile-harassing gulls near the marina and 2nd bridge
Habitat: Open water of Great Salt Lake
Similar species and how
were they eliminated:
Long-tailed Jaegers are smaller and more delicate, adults have much longer R1 tail feathers, Juveniles have blunt R1 tail feathers, not pointed tail feathers like the juvenile I saw.

Pomarine are larger and more bulky, adults have twisted spoon shaped R1 tail feathers, juveniles are almost unheard of in fall in the western USA, virtually all are dark morphs, unlike the juvenile I saw, and have blunt R1 tail feathers
Previous experience with
this & similar species:
Yes, I had seen a Parasitic Jaeger 2 weeks earlier in the same location. However that bird was a juvenile intermediate morph, the juvenile I saw on this morning was a light morph so a different individual.
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: Many others had reported seeing these 2 Jaegers. Including Nick and Logan Smith and Steve and Cindy Sommerfeld, Mark Thal and a friend joined me as I was watching the juvenile
Date prepared: 1-3-2020
Additional material: Photos
Additional comments: Logan and Nick smith got excellent photos of the adult Parasitic Jaeger, which can be seen here:

My eBird checklist: