Verification of Unusual Sight Record
For Utah

Rec. # 2016-28

Common name:

White-rumped Sandpiper

Scientific name: Calidris fuscicollis
Date: 09-07-2016
Time: 2:45pm
Length of time observed: 10 minutes
Number: 1
Age:  ?
Sex:  ?
Location: Antelope Island Causeway
County: Davis
Elevation: 4200ft
Distance to bird: 100m
Optical equipment: Bushnell 20-48X spotting scope
Weather: Clear, 80F
Light Conditions: Good
Description:        Size of bird: Medium sized Peep (7.5)
(Description:)       Basic Shape: Long bodied peep, wing extended just past the tail
(Description:)  Overall Pattern: Overall very pale cold gray with a streaked breast and black legs
(Description:)            Bill Type: Long,slightly decurved and black
Field Marks and
Identifying Characteristics:
There were 3 rocky islands south of the 2nd bridge because of the low water, on those islands were thousands of Peeps, mostly Westerns. Shortly after we arrived, a juvenile Peregrine came through and put all the peeps up in the air, and it made several passes causing murmurations of peeps as they tried to out maneuver the Peregrine, then they all flew off to the west as the Peregrine settled on one of the Islands. But the gulls and Curlew were unconcerned with the Peregrine and stayed. After the Peregrine left I put a scope on the Curlew to make sure none were Whimbrels, none were, then I noticed one lone peep that stayed behind in the rocks. It was overall very pale gray, with a prominent supercilium and wings extending past the tail, but what was most unique is the breast had prominent gray streaks. Unlike a Baird's, it was overall a very cold gray, almost as pale as a Western, and the breast wasn't as solid, more streaked with prominent pale gaps between the streaks. Later the Westerns returned and it was noticeably larger.
Song or call & method of delivery: None heard
Behavior: Loafing on a small rocky island near the causeway, at first alone, then joined by thousands of Western Sandpipers
Habitat: Great Salt Lake
Similar species and how
were they eliminated:
Least-Much smaller, wings not extending past tail, yellow legs

Western-Smaller (direct comparison) and without wings extending past tail, and with a very pale white breast

Bairds-Its hard to describe, but it had a different facial pattern than a Baird's, with a strong supercilium and dark eyeline, it didn't seem to have as prominent of an eyering. I've been looking at many Baird's lately on the AIC as well as Utah Lake SP, and it just had a totally different gestalt, most important being the very cold gray tones, not the warm chestnut brown tones of a Baird's. It also had a smooth gray back, lacking the dark spots of a Baird's. It never flew so I never saw the white rump

Semipalmated-Smaller, shorter billed and with prominent dark spots on the back. Wings not extending past tail

Pectoral-Larger, yellow legs, rich warm brown tones

Dunlin-Larger, much longer legs and bill, brown breast

Wilson's Phalrope-Sometime they get on mudflats and walk around like a Peep, and can be rather confusing, but in non-breeding plumage are very pale breasted, and have yellow legs
Previous experience with
this & similar species:
None with White-rumped, lots with Baird's, Least, Western, Semipalmated, Pectoral, Dunlin, Wilson's Phalarope
References consulted: Sibley, National Geographic, iBird Pro, eBird
Description from: From memory
Observer: Bryant Olsen
Observer's address: 688 East 700 South #105
Observer's e-mail address: **
Other observers who independently identified this bird: Vivian schneggenburger, and Lauri Taylor were with me and saw the bird, but were relying on me to ID the it.
Date prepared: 09-08-2016
Additional material:  
Additional comments: