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: 4122'46.69"N 11207'59.85"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