Verification of Unusual
Sight Record
For Utah
Rec. # 2013-49
| Common name: |
Least Tern |
| Scientific name: | Sternula antillarum |
| Date: | May 27, 2013 |
| Time: | 0930 |
| Length of time observed: | ~ 10-15 minutes |
| Number: | 1 |
| Age: | Adult |
| Sex: | unknown |
| Location: | Willard Spur |
| County: | Box Elder |
| Latilong: | 41°22'46.69"N 112°07'59.85"W |
| Elevation: | 4209 |
| Distance to bird: | 40 feet to 300 yards |
| Optical equipment: | 8 x 42 binos, 85 mm scope with 20-60x zoom eyepiece |
| Weather: | Clear, bright, temps in the 60's |
| Light Conditions: | Sunny |
| Description: Size of bird: | Half the size of a Forster's Tern or less |
| (Description:) Basic Shape: | Slim and swoopy |
| (Description:) Overall Pattern: | White, gray, black |
| (Description:) Bill Type: | Narrow, dagger-like |
|
(Description:)
Field Marks and Identifying Characteristics: |
General: Long-winged, slim, short-legged while standing on shore; mostly
horizontal aspect. Black cap, gray upperparts, white underparts. Head Small yellow bill; smaller in proportion to LETE than Forster's Tern bill is to FOTE. White triangle from bill to about halfway up the forehead. Black crown through nape. Face showed black line extending from base of bill through the black eye and to the black crown at nape. Black line formed the bottom border of the white forehead triangle and divided triangle from white cheek. Body Uniformly gray back and wings, slightly darker than Forster's Terns, also present and standing nearby. Forward leading edge of wing at primaries appeared black in flight. Did not see wingtips or tail while standing. White underparts from throat past legs. Legs yellow, possibly a shade of yellow-orange. (see photos) |
| Song or call & method of delivery: | None heard. |
| Behavior: | Standing on gravel peninsula with Forster's Terns, a Franklin's Gull, Snowy Egrets and Killdeer. More sedate than others; did not flush but remained when Forster's flushed twice. Once, LETE tucked bill into scaps and remained alone. Ranged out over water a couple times showing tiny size, uniform gray upperparts and black leading edge of wing at primaries. Landed with a large group of terns ~300 yards out, but did not mix with flock. |
| Habitat: | Expansive, shallow, brackish marsh. |
| Similar
species and
how were they eliminated: |
Yellow bill and diminutive size eliminate all other terns. |
| Previous
experience with this & similar species: |
None with Least; Forster's, Common, Caspian annually |
| References consulted: | Images of this bird and recent Powell Lake LETE; Sibley |
| Description from: | Notes taken at the time of the sighting |
| Observer: | Kristin Purdy |
| Observer's address: | Ogden, Utah |
| Observer's e-mail address: | ** |
| Other observers who independently identified this bird: | Paul Higgins, discoverer |
| Date prepared: | May 29, 2013 from 5/27/13 notes |
| Additional material: | photos |
| Additional_Comments: | Notes taken independently of images |