Verification of Unusual
Sight Record
For Utah
Rec. # 2026-75
| Common name: |
Wedge-rumped Storm-Petrel |
| Scientific name: | Hydrobates tethys |
| Date: | 12Oct2026 |
| Time: | 11:20 AM |
| Length of time observed: | 1 hour 45 minutes |
| Number: | 4 (Very likely that there were at least 5) |
| Age: | Adult appearance |
| Sex: | Not determined |
| Location: | Sand Hollow Reservoir |
| County: | Washington |
| Latilong: | 37.110598, -113.388051 |
| Elevation: | 3,040 feet |
| Distance to bird: | Flyby- one bird at 60'; 4 were floating on the water- as close as 350' |
| Optical equipment: | Nikon Z8 camera with 600mm f4 lens, 10x bins, spotting scopes of adjacent birders |
| Weather: | Overcast with calm wind |
| Light Conditions: | Good |
| Description: Size of bird: | Small Storm-Petrel, estimate 6-7 inches in length |
| (Description:) Basic Shape: | Small compact seabird with notched tail. |
| (Description:) Overall Pattern: | Dark/ black with extensive white on the rump |
| (Description:) Bill Type: | Black, thick tube-nosed bill with a small hook at the tip |
|
(Description:)
Field Marks and Identifying Characteristics: |
Small Storm-Petrel, black or very dark brown, bill was black and fairly
thick and hooked at the tip, large white rump patch- the distal 1/2 to
1/3 was V-shaped at the rear and it extended on the sides of the rump,
notched tail. (see photos) |
| Song or call & method of delivery: | Did not hear any vocalizations |
| Behavior: | Resting on the water, and bounding, erratic flight |
| Habitat: | Large reservoir |
| Similar
species and
how were they eliminated: |
Wilson's- it was ruled out because the white rump patch was more
extensive and V-shaped at the rear, and extended closer to the end of
the tail. Leach's- it was ruled out because the notch in the tail was shallower, and the white rump patch was more extensive, and the wings were not as angled and pointed. Townsend's- it was ruled out because the white rump patch was more extensive and the notch in the tail was shallower. |
| Previous
experience with this & similar species: |
None with this species. Have seen Wilson's and Ashy on several pelagic trips. |
| References consulted: | eBird, Sibley |
| Description from: |
From memory From photo(s) taken at the time of the sighting |
| Observer: | Maurice DeMille |
| Observer's address: | La Verkin, UT 84745 |
| Observer's e-mail address: | ** |
| Other observers who independently identified this bird: |
Kevin Wheeler, Steve Sommerfeld, F Alvarez, Tony Jones, James Loveless |
| Date prepared: | 15Oct2026 |
| Additional material: | Photos |
| Additional comments: |