Verification of Unusual Sight Record
For Utah

Rec. # 2007-13

Common name:

White-rumped Sandpiper

Scientific name: Calidris fuscicollis
Date: 3 June 2007
Time: approx. 4:00 P.M.
Length of time observed: about 20 minutes
Number:  3
Age: adult, alternate plumage
Sex: ?
Location: at the north end, east of the observation peninsula, of Blue Grass Pond on Deseret Ranch, about 4 miles SSE of Woodruff, Utah
County: Rich
Latilong: about 6,100'
Distance to bird: closest observation at about 25 meters
Optical equipment: Leica 10x42 binoculars, Leica 77mm spotting scope, 60x
Weather: mostly cloudy, cool, no significant wind, a few showers occured later
Light Conditions: mostly excellent, with sun (mostly behind clouds) behind the viewers, lighting was nearly perfect while the birds were on the shore, becoming more difficult when the birds were in the water
because of reflected clouds
Description:        Size of bird: appeared to be a largish "peep," but was smaller than all of the other shorebirds present, appeared slightly smaller than Spotted Sandpipers nearby
(Description:)       Basic Shape: Typical Calidris sandpiper-shaped, legs not especially long, but with a longer, more tapered look to the body because of long wings, with the wingtips obviously longer than the tail at rest
(Description:)  Overall Pattern: Generally white below, mottled black, grayish-brown and rusty above, rusty crown, black streaks on breast and flanks
(Description:)            Bill Type: thin and tapered, slight droop at the tip
Field Marks and
Identifying Characteristics:
Shape: Like a typical Calidris, though longer and more slender than most, with long wings extending beyond the tail giving its body a longer, more tapered look.

Bill: Black, slightly longer than the head, wide at the base and tapering rapidly to a blunt tip. Bill thinner at the tip than on Sanderling, but thicker than Baird's. The tip droops slightly.

Legs: Black, medium length for a sandpiper.

Plumage: Crown finely streaked with dark markings against a rusty background, giving an overall rusty apearance to the crown. A whitish supercilium separates the crown from a darkish line in front of the eye and rusty auriculars behind the eye. The upperparts are generally mottled with warm to grayish brown with lighter feather edges. The scapulars have large, blackish centers, and some rusty tones are present above the scapulars and shoulders. The upper tail coverts are completely white across the rump, a feature that was plainly visible as the birds preened and flew. The tail appeared dark above. The underparts are entirely white, with heavy black markings on the breast and upper flanks against the white background. The markings in places form streaks, especially on the center of the breast, and become more disorganized and coarser on the flanks. On at least one of the individuals, the rear-most spots on the flanks are chevron-shaped. The belly is clean white.

(see photos)
Song or call & method of delivery: none noted
Behavior: All three birds were mostly feeding or resting on the mudflat and in the adjacent shallow water. They associated loosely with one another. Occasionally they would bathe and/or preen, and made several short flights
Habitat: mudflat on the edge of a shallow lake with marshy shoreline amid sagebrush-grassland and wet meadows
Similar species and how
were they eliminated:
The general shape and behavior eliminates all birds other than small sandpipers.

The white upper tail coverts separates this species from all other small sandpipers.

The wingtips extending beyond the tail eliminates Western, Semipalmated and Least Sandpipers, as well as rarer sandpipers such as stints. The black legs eliminate Pectoral and Sharp-tailed Sandpipers.

The two most likely to be confused species would be Sanderling and Baird's Sandpipers. Sanderling can be safely eliminated by its rustier upperparts in breeding plumage, and paler grayish upperparts in non-breeding plumage. In no plumage does it show the streaking/speckling on the breast and flanks that these birds had. Also, the Sanderling bill is a bit shorter, straighter, and stouter than the bills on these birds.

Baird's Sandpiper in breeding plumage does not have the rusty color on the crown, auriculars or scapulars, nor does it have an obvious whitish eyebrow - all features these birds showed. The bill on Baird's tapers to a finer point than the the bill on these birds. Baird's Sandpiper has finer streaking on the breast with a buffier background color - not the rather heavy black markings against a white background of these birds.

Neither Sanderling nor Baird's Sandpiper have a white rump.

Records show this to be one of the most likely "peeps" in early June in Utah.
Previous experience with
this & similar species:
I have seen and photographed this and all similar species many times.
References consulted: National Geographic Field Guide, Shorebirds of the Pacific Northwest, Birds of North America Online, Utah Birds website
Description from: From memory
Observer: Mark Stackhouse
Observer's address: 1432 Downington Ave, Salt Lake City, UT 84105
Observer's e-mail address: Email:
Other observers who independently identified this bird: David Wheeler, although reluctant at first, finally saw the light (shining from the white rump)
Date prepared: 7 June 2007
Additional material: Photos
Additional comments: