Sighting Record for Utah

Common name:	White-rumped Sandpiper
Scientific name:	Calidris fuscicollis
Date:	09/02/2016
Time:	1:30 PM
Length of time observed:	~2 minutes
Number:	1
Age:	Unknown
Sex:	Unknown
Location:	Utah Lake State Park
County:	Utah
Latilong:
Elevation:	4,488'
Distance to bird:	100'
Optical equipment:	8x42 Binoculars, 20-60x82 spotting scope, and a 500mm lens
Weather:	Overcast and windy following a squall across the lake
Light Conditions:	Overcast, so darker than usual
Description: Size of bird:	Large sandpiper
(Description:) Basic Shape:	Sandpiper
(Description:) Overall Pattern:	brown, gray and white
(Description:) Bill Type:	typical probe bill
(Description:) Field Marks and Identifying Characteristics:	Saw sitting on mud flats with Baird's and Pectoral Sandpiper. Smaller than Pec, similar in size to Baird's, but mostly grayish with some brown in the mantle. Bill had a slight pale streak on the lower mandible at the base. In the lighting the color was impossible to ascertain, but it was obviously pale. Also, could make out a slight "eyeline" of paler feathers. This was not obvious in flight though. The birds took flight and I was able to snap a shot showing the white-rump nicely, with a Killdeer in the foreground for size. In the background is another piper that appears to be a BAird's Sandpiper but is showing a lot of white on the side of the rump. I never actually looked at that bird in the field so I can't really talk more about it. (see photo)
Song or call & method of delivery:	none heard or noticed
Behavior:	Standing on mudflats with large flock of peeps and other shorebirds avoiding the high winds and rain blowing across the lake. As the squall passed the bird took flight and all headed back to the lake side of the marina.
Habitat:	Mudflats in drying up marina lake bed on the shore of shallow lake with extensive mudflats.
Similar species and how were they eliminated:	Baird's Sandpiper is a pale brownish color and doesn't have a white rump, or pale base to the lower mandible.
Previous experience with this & similar species:	Have seen numerous times in the midwest, as well as several times in Utah now. See Baird's Sandpiper annually during fall migration.
References consulted:	None.
Description from:	Notes made later
Observer:	Tim Avery
Observer's address:	Sandy, Utah
Observer's e-mail address:	**
Other observers who independently identified this bird:
Date prepared:
Additional material:	Photo
Additional comments:	Photo Here: http://www.timaverybirding.com/photos/displayimage.php?album=lastup&cat=-557&pid=16040#top_display_media