Vermont Rare Bird Reports 2022

Fred Pratt -

Mostly sunny, calm, mid 70s F.

Vortex Diamond Back HD Spotting Scope, 20-65 x 85

Observed a "lifer" WESA at this location last year (9/25/21) on same section of mud that was confirmed by Scott Morrical and photographed by David Guertin. Fairly intensive shorebirding experience in Vermont over last 2.5 years with very experienced birders such as Allan Strong (including some jaunts to Maine and Massachusetts shores). Fred Pratt joined me for the second siting described below. He is of course well known in the Vermont birding community and has many decades of extensive experience, including with WESA. It was ultimately through discussing and observing the bird with Fred that I had the confidence to list as a WESA.

Extensive mudflats along eastern and western shores of Dead Creek on south side of Panton Rd. cross and pull-off. Other shorebirds observed included SESA (6), LESA (47), WRSA (3), KILL (8), SEPL (3), SPSA (1), LEYE (1), and GEYE (1).

Initially observed feeding with other peeps on mudflats directly in front of me from eastern shore trail. Peeps were moving around in the area, flying to alternate sides of Dead Creek along extensive exposed shoreline and muddy peninsula. My presence did not seem to disturb bird. No notable displays beyond typical peep feeding behavior.

No vocalizations particular to this individual identified. Only largely LESA (the majority peep) and some SESA flight calls noticed when birds were on the move. KILL were also vocal.

While scanning the mudflats for an initial assessment of shorebird counts and diversity, I noticed a bird that first fit my SESA mental model (peep size, black legs, black bill), however the bill was clearly longer with a droop and the bird a bit larger than nearby SESA. While the plumage was SESA-like, I immediately noticed distinct rusty-colored (rufous) upper scapulars with a different feather pattern than the grayish lower scapulars. Since I had seen a WESA on this exact mudflat last year, I immediately though "WESA?!?!". I studied the bird for perhaps 2 minutes through the scope, comparing bill, plumage, and overall size to nearby SESA and LESA, as well as observing shape and length of primary projection relative to tail to rule out WRSA (which were also near by). As the bird moved to a bigger group of peeps, I tried to take an iPhone pic through my scope without any luck. I lost the bird during a flight of the group and began to take eBird notes and tally other species present. Fred Pratt later arrived in the parking lot and after a harrowing trek out to my vantage point, we managed to find the bird again with a group of peeps on the opposite shore. We were able to share scope views and discuss the various characteristics of the bird that ultimately led to a confident WESA identification.

Just a tad bigger than nearby SESA, clearly bigger than LESA in the group, and smaller than nearby WRSP. Bird seemed to have a rounder, more puffed up appearance than SESA, or a bit "front heavy" (a characteristic I remembered Scott Morrical noted from last year's WESA siting at this location).

No rusty or rufous tones on head that would be expected with breeding plumage or a younger "fresh" juvenile WESA. Otherwise typical SESA/WESA pattern of pale face, with whitish throat blending into a grayish-brown neck/upper breast (what Fred described as a "a soft brown partial breast band" typical of a juvenile WESA). No spotting.

Black legs, feet and bill. The bill was the best clue, especially in comparison to SESA. Fred described well as "obviously longer, thinner, and clearly down-turned at the tip."

Another key diagnostic feature was the rusty/rufous colored upper scapulars, brightest on shoulder with a different feather pattern than lower scapulars. It was more difficult to make out colors with more distant views once I refound the bird with Fred, but he noted the "scapulars of the Western were more patterned and showed a richer wedge of pattern on the upper scapulars." Looking later at my Sibley's 2nd edition, there is a nice illustration of differing plumage of WESA by age on p. 181. The bird most resembled "worn juvenile", the 2nd of 7 plumage illustrations.

Lower back with grayish-brown tones of typical SESA or WESA plumage, but not as light or all gray like non-breeding plumage.

Most notably, the primary projections did not extend beyond tail like a WRSA or BASA.

Light grayish-brown wash (a whitish impression) on breast gave way to very white belly and undertail coverts. White underparts gave an impression of a very "bright" bird. No spotting or stripping.

Most notably, the wings did not extend beyond the tail as with a WRSP or BASA. Tail plumage of a "worn" juvenile or transitioning adult.

SESA ruled out largely because of length and down curve to bill. Direct comparisons were made with the shorter, blunter bills of nearby SESA during my early observation, as well as during the second observation with Fred Pratt when we thoroughly discussed the bill characteristics. The color and distinctiveness of the upper scapulars were also more like WESA.

LESA was ruled out based on size and leg color, with the WESA (and SESA) clearly the larger peep species with black (vs. greenish yellow) legs. The bird's "color palette" was also more like the grayish tones of a WESA or SESA than the more overall brownish (and darker) tones of a LESA.

WRSA was also ruled out as the primary projection did not extend beyond the tail and lacked a tapered body appearance. It also did not have a white rump, observed briefly while preening during second observation. The bird was also clearly smaller than nearby WRSA observed during first observation. BASA was also ruled out due to lacking primary projection beyond tail, different color palette of plumage, and a more buffy breastband.

Fred and I discussed whether this individual was an adult transitioning between breeding and non-breeding plumage, or a juvenile. Based on above (and Fred's extensive experience), juvenile seems most likely.