Sighting Record for Utah

Common name:	Least Storm-Petrel
Scientific name:	Hydrobates microsoma
Date:	10/12/2026
Time:	2:30pm
Length of time observed:	15 minutes off and on
Number:	1
Age:	?
Sex:	?
Location:	Utah Lake North Shore
County:	Utah
Latilong:	40.359743, -111.886170
Elevation:	4,500ft~
Distance to bird:	400m~
Optical equipment:	Kowa 20-60x 88mm spotting scope
Weather:	Calm, partly cloudy, 60F
Light Conditions:	Good, sun was mostly in the clouds
Description: Size of bird:	small Storm-Petrel
(Description:) Basic Shape:	Strom-Petrel shaped
(Description:) Overall Pattern:	all dark
(Description:) Bill Type:	too far to see details
(Description:) Field Marks and Identifying Characteristics:	We had chased the Strom-Petrels being reported at River Lane and Lincoln Point, then decided to hit North Shore on the way home since Dee and Matt had reported seeing some from the new Marina there. Upon our arrival David and Lauri were already there and on 2 Storm-Petrels, This Storm-Petrel we saw directly east and we all got on it in our scopes. 1st noted it had an all dark rump, unlike the Storm-Petrels we had seen earlier at other locations. It had a very fast and erratic bat like flight, often swerving and landing briefly. It appeared small but was at a distance with nothing to compare. It appeared all dark blackish, including the wings, tail and rump. But what set it apart as a Least was the tail shape. It did not have a square or notched or forked tail, but a short rounded spade shaped tail. We all observed this several times as it would flutter and land. No other Storm-Petrel has a spade shaped rounded tail other than Least.
Song or call & method of delivery:	None heard
Behavior:	flying over Utah lake to our east
Habitat:	Open fresh water of Utah Lake
Similar species and how were they eliminated:	Black Strom-Petrel-longer wings and a long forked tail Leach's/Townsend Strom-Petrel- Forked or notched tails, often have either some white or buff in the rump (we had another Strom-Petrel at this location that was one of these with a white and buff rump clearly visible.)
Previous experience with this & similar species:	None with Least, but some with Black, Ashy, Leach's and earlier that day presumed Wedge-rumped Storm-Petrel
References consulted:	Sibley and Merlin app in the field, Macaulay Library photos and video after
Description from:	Notes taken at the time of the sighting
Observer:	Bryant Olsen
Observer's address:	Address: 84105
Observer's e-mail address:	**
Other observers who independently identified this bird:	Max Malmquist, David Wheeler, Lauri Taylor and Marissa Noelle also viewed it at the same time, Quinn Diaz reported this species here the next day.
Date prepared:	10/16/26
Additional material:	Video by Max Malmquist
Additional comments:	eBird checklist: https://ebird.org/checklist/S401828489 Max has some video on eBird