Sighting Record for Utah

Common name:	Parasitic Jaeger
Scientific name:	Stercorarius parasiticus
Date:	July 28, 2026
Time:	5:05pm
Length of time observed:	1 hour and 25 minutes
Number:	1
Age:	Adult
Sex:	Unknown
Location:	Antelope Island State Park Causeway
County:	Davis
Latilong:	41.0726835, -112.2283043
Elevation:	5,325
Distance to bird:	0.17 miles
Optical equipment:	Zeiss Conquest 8x42mm Binoculars, Vortex Viper HD 20-60x85 Angled
Weather:	Sunny, low cloud coverage
Light Conditions:	Bright and harsh, bird was backlit for the entirety of its perching, but was well-lit when it flew north over us on the causeway
Description: Size of bird:	Relatively small in terms of gull-like birds. Roughly about the size of a RBGU, about a third smaller than CAGU
(Description:) Basic Shape:	Gull-shaped
(Description:) Overall Pattern:	Sandwiched: dark head, wings, and tail, with light belly
(Description:) Bill Type:	Long, thin, slender bill
(Description:) Field Marks and Identifying Characteristics:	MDG and I had just finished scanning the flocks of shorbs and gulls to the north and were making our way to the south side of the causeway. MDG started looking through the scope when I noticed a gull-like bird flying towards us from the southwest. I noticed that it was flying a little weird and didn't give me the immediate vibe of a CAGU. I said "what's this weird gull thing flying toward us?" but was expecting it to turn out to be a CAGU once it got closer. I had only first noticed it when it wasn't too far from us, but still far enough for me not to immediately see fieldmarks due to lighting. Since it was getting closer, though, I figured I could ID it with naked eye rather than putting the bird in bins. When it went overhead, I saw the distinct face pattern with the dark cap and white chin (this bird was a nonbreeding plumage adult) and blurted out "is that a Jaeger??" to which MDG whipped around, saw the bird, and we both excitedly confirmed that we did indeed have a jaeger on our hands. I initially deferred to him for the ID since he had more experience with Parasitic and Pomarine Jaeger. He had thought that it was a Long-tailed at first due to the petite and slender feel of the bird, but we immediately started to take as much media as we could. The bird also flared its tail in flight, showing us the longer, central rectrices characteristic of jaegers. The next hour of viewing this bird was coupled with crash course jaeger ID with the help of Sibley and texting other birders. Thankfully it was perched out on a (gull?) carcass picking at it, but it was very backlit while doing so. We focused on bill and trying to get an underwing shot. It took off a couple times but thankfully returned back to the carcass until it left for good, giving us decent views of it perched and flying. Photos and videos will show that this bird is clearly a jaeger. - Long, thin bill - Prominent white flash at the base of the primaries in the underwing shot, seen while perched and in flight - Very slight secondary light flash at base of primary underwing coverts - Cap not cleanly defined - Apparent breastband that wraps around the front of the body - Short but pointed central rectrices (see photos videos)
Song or call & method of delivery:	NA
Behavior:	Floating, swinging flight style accompanied with occasional bursts of heavy flapping. Perched for the majority of viewing on a carcass, picking and eating at it. We did not observe the characteristic chasing behavior of this species.
Habitat:	Observed over and on playa and flats of the GSL.
Similar species and how were they eliminated:	Pomarine: MDG had ruled out Pomarine from the getgo because of the size and sleek shape, and I agree that Pomarine doesn't fit due to the small size of our bird (mostly lack of barrel-chestedness) and its pointed center rectrices. Pomarine also has a more prominent second white flash on the primary underwing coverts, whereas our bird has only a very slight flash there. Long-tailed: This was the hard one to rule out, especially because MDG was already thinking that this might be a LT due to the slenderness of the bird. I also thought that the time of year made more sense for LT rather than Parasitic (being more of a September record), although there aren't many records of these birds to go off of. We ended up going with Parasitic over LT because of this individual's prominent white flashes and long and thin bill. LT has a smaller white flash on the primaries, typically surrounding the two outermost primaries. LT would have a stubby looking bill because of its shorter length and larger bill nail in comparison. The breast band is another point for Parasitic, especially because this is an adult plumage bird.
Previous experience with this & similar species:	AC: Little experience with far looks at Parasitic Jaeger during seawatching in Cape May, NJ. Experience with the expected gull species in Utah and on the causeway. MDG: Experience observing differentiating Parasitic and Pomarine during seawatching and pelagic/whale watches in the gulf of Maine.
References consulted:	The Sibley Guide to Birds Second Edition, Alex Lamoreaux (advice from taken media), KC Childs (advice from taken media)
Description from:	From photo(s) taken at the time of the sighting
Observer:	Allison Cao
Observer's address:	11366 S Stoker Cove, South Jordan, UT 84095
Observer's e-mail address:	**
Other observers who independently identified this bird:	Matthew Gilbert
Date prepared:	August 6, 2026
Additional material:	Photos Videos (eBird checklist and Mathew's )
Additional comments: