Sighting Record for Utah

Common name:	Gyrfalcon
Scientific name:	Falco rusticolus
Date:	2022/04/07
Time:	10:00
Length of time observed:	Roughly 90 seconds
Number:	1
Age:	Juvenile
Sex:
Location:	Halfway up Middle Bowl, Snowbasin
County:	Weber
Latilong:	41.19492 -111.87379
Elevation:	8800 feet
Distance to bird:	50 yards
Optical equipment:	None
Weather:	Partly Cloudy and sunny
Light Conditions:	Bright morning light, plenty of light reflecting off of snow.
Description: Size of bird:	Large Falcon
(Description:) Basic Shape:	Broad rounded wings, thick stubby body.
(Description:) Overall Pattern:	Clean white underwing besides dark auxiliaries/greater coverts. Never got a great look at upper side but appeared mostly white/grey.
(Description:) Bill Type:
(Description:) Field Marks and Identifying Characteristics:	Noticed a large white bird flying in circles, presumably rising in a thermal. Its body was thick and stubby. I resonated with an analogy from a guide that it looked like a football. Wings were noticeably broad and round. Immediately striking were the black axillaries and greater coverts on the underwing, lit up well from snow reflected light, and contrasting strongly with everything else that was stark white. It occasionally flapped (I did not note exactly how often), and I immediately recognized it as a falcon's flight. Its wing beats were very weak (not powerful, or not graceful, Recalls SSHA) yet noticeably deep (I almost want to say powerful? That doesn't make any sense. I don't know how to describe it. It's a very ethereal thing to describe. Recalled PEFA). It rose for approximately 70 seconds, then began to glide across the ridge of cliffs north of Needles Lodge. As it began to turn across the ridge, I caught a short glimpse (3 seconds at best) of the upperside. I can only describe it as being darker than the underside (possibly lighting), but with a noticeable tint of brown (not sure where exactly on the bird, I just saw brown). (see drawings)
Song or call & method of delivery:
Behavior:	Rose in a thermal, then glided North across a ridge.
Habitat:	High alpine, cliffy
Similar species and how were they eliminated:	Clearly a Falcon/Accipiter from flight pattern. Much too large for an Accipiter. Only possible confusion would be with an unusually large NOGO, which plumage eliminates. An adult NOGO underwing can appear two-toned, but this comes from the primaries/secondaries appearing dark. This bird very clearly had dark GC/axillaries, recalling PRFA. As for other flacons, much too large to be AMKE or MERL, appeared larger than a typical PRFA or PEFA. PRFA is the most similar plumage-wise to what I saw, with the underwing pattern of dark, contrasting Greater coverts/axillaries. The body was very large and stubby for a PRFA, and the wings of a PRFA are more tapered and pointy. The wingbeats of the bird observed also appeared deeper. The habitat would also be incredibly unusual for a PRFA. I can only find a few records above 8000', and all of them were in the summer (July). According to Jerry Liguori in Hawks At A Distance, "Rarely, juvenile grey Gyrfalcons have dark mottling along the underwing linings similar to those of Prairie Falcons, but these marking are less bold than on Prairie Falcons, and the dark wing pits of Prairie Falcon are absent on Gyrfalcons." This is supported by several images on Macaulay Library. The description says that the "dark wing pits" are absent, but from what I'm seeing from photos on Macaulay Library, the black simply does not spread as much in the axillaries. That is how I'm interpreting the descript ion from Jerry Ligouri, which does not contradict the bird I observed. PEFA is the most similar GISS-wise, however, it should never show an underwing pattern as described.
Previous experience with this & similar species:	I have a moderate ammount of experience with all other breeding falcon species and COHA/SSHA, from casual Hawk-watching while birding. I have zero experience with GRFA
References consulted:	Hawks at a Distance - Jerry Liguori Birds of the World - Cornell Labs Macaulay Library - Cornell Labs
Description from:	Notes taken at the time of the sighting
Observer:	Connor Johnson
Observer's address:	1387 N 2050 E Layton, UT
Observer's e-mail address:	**
Other observers who independently identified this bird:
Date prepared:	2022/05/30
Additional material:	Drawings
Additional comments:	I was skiing, so I had zero optics. Just my luck to get extremely lucky. I put off writing this for months, and I apologize. I needed to focus on school. This record was constructed based on notes I made at the time of the sighting.