Subject: Little Stint Date: Sep 9 17:44:16 1994 From: Greg Gillson - gregg at tdd.hbo.nec.com
Readers of Oregon Birders On-Line will recall that on Monday I had seen a "mystery sandpiper" that I was unable to identify. Well, with some research, and hints from some of you, I have reached a descision:
[Well, there goes my good reputation! (I did have a *good* reputation, didn't I?)]
Following is my report to the Oregon Bird Records Committee. If not accepted, at least it will give them something to debate for a while!
-- Greg Gillson <gregg at tdd.hbo.nec.com> Hillsboro, OR
Fernhill Wetlands, Forest Grove, Washington Co., Oregon Monday, 5 September, 1994
Greg Gillson 311 Park Street Banks, OR 97106
Description: Small shorebird in with flock of juvenile Western Sandpipers feeding on edge of water, seldom wading in. Slightly smaller than any other male Western Sandpiper present, and chased away by every other Western. Much rustier on wings and back than Western Sandpiper. The bill was shorter than the head, stout, coming to a blunt end. The legs were black. A bright white line of feathers separated the upper and lower scapulars. All feathers of the wing were clean and bright, with wide margins indicating juvenile plumage, which is expected at this time of year.
Upon closer inspection, two diagnostic marks, which eliminate Western Sandpiper, were noted: 1) the toes were definitely unwebbed, and 2) the pattern of the lower scapulars were solid black centers with reddish-brown fringes.
The toes connected directly to the leg without the appearance of the "foot" that Western Sandpiper shows. I had several views in which the spread toes merged together sharply with no palmation.
All feathers of the wing were rusty; the upper scapulars and tertials had solid black centers with bright rufous edges (the "chestnut" color of Western's scapulars); the lower scapulars as well had black centers and reddish-brown edges, the rest of the wing coverts were paler and fringed with pale rusty.
The crown was darker than most Western Sandpipers, made up of short black and brown streaks. This made the broad pale eyebrow more apparent as if flared out behind the eye. The ear coverts and hind-neck were buffy-brown. The upper breast was also buffy-brown breaking into indistinct streaks on the sides of the upper breast.
Details of observation: +15 minutes at about 3:15 p.m. Bird observed at distances between 60-80 feet with 22x scope. Sunny skies. The bird was in an east-southeast direction from the observer, while the sun was high overhead to the southwest. This was on the east side of the large (north) pond of the former Forest Grove sewage facility. The pond was nearly dry, and I was able to walk out on the pond bed quite a ways, but the birds concentrated near the dike on the south edge.
Other shorebirds present: Killdeer 15 Greater Yellowlegs 3 Spotted Sandpiper 2 Western Sandpiper 50 Least Sandpiper 10 Pectoral Sandpiper 3 Long-billed Dowitcher 3
Elimination of similar species: Western Sandpiper: The observed bird was very similar to a small juvenile male Western Sandpiper in bill and body shape. I am quite confident that the toes of this bird were unwebbed. In addition, the centers of the lower scapulars were solidly black, not brownish with black "anchor-shaped" marks. The dark- centered tertials with bright rufous edges are also not typical of Western. The crown and eyestripe showed more contrast than juvenile Westerns.
Least Sandpiper: The darker coloration of the upperparts of the observed bird, coupled with the wash on the upper breast, made Least Sandpiper a logical choice. Besides the jet-black legs, the observed bird had a shorter, blunter bill than the thinly tapering bill of Least Sandpiper.
"Rufescent" Semipalmated Sandpiper: Basically, the same argument against Western Sandpiper applies to this bird: the observed bird lacked webbing between the toes, and had dark, rather than pale centers to the lower scapulars and tertials. The crown and ear covert of the observed bird were not rufous.
Rufous-necked Stint: This bird does have the unwebbed toes of the observed bird, and the generally short bill. But this sandpiper has gray centers with dark shafts and subterminals, the "anchor" shape, to lower scapulars, wing coverts, and tertials, unlike the observed bird.
Discussion: I have no experience with Little Stint outside of this observation. Even though my observations all seem to point to Little Stint, and to eliminate all other candidates, I am not terribly confident of the identification. This must be a species that, like Empids, require experience to be confident in identifying.
I observed the bird on Monday, but didn't reach an identification until Friday. This was due to time restraints, but also aided by e-mail from Michael Price <Michael_Price at mindlink.bc.ca>, who read a description of my "mystery sandpiper." I spent considerable time (again) reading "Field identification of smaller sandpipers within the genus Calidris" by Veit and Johnson, in American Birds Vol. 38, N. 5 (Sept-Oct 1984).
Interesting comments from Michael Price: "Some juv Western Sandpipers (WESA from here on) have distinctly buffy fringes to coverts...but WESA scaps have rufous *centers* with black subterminal tips." Regarding separating 'rufescent' Semipalmated Sandpiper from Little Stint: "Nowadays, the SESA-- LIST I.D. problem is much more well-known in the US & Can. The concensus of Brit & European shorebird junkies is they can sometimes be so similar that *only* by seeing whether the toes are webbed or unwebbed can you separate them." He noted about my observation: "The other marks, incidentally, are also consistent with LIST, as is the fact it got pounded on by the rest: SESA is usually as truculent as WESA and normally won't hesitate to duke it out with anyone."
There are 2 previous records of this stint in Oregon accepted by the Rare Bird Records Committee.