Photo Quiz #12 Answer
By Jim Burns
After a couple relatively easy Arizona quizzes I thought it might be fun to go a little farther afield for once. If you glanced at this issue's cover and your brain said "peep," and you thought Least Sandpiper or maybe Western, and then you read the caption, you'll know where we're going.
Matching photos of shorebirds we'll never see in Arizona with illustrations from our favorite field guides is a good exercise in learning how to look at shorebirds. Shape and structure should take precedence over plumage and field marks, and dealing with black and white is going to force us to go to school.
Our cover bird offers a good example. In the field, Long-toed Stint is nearly inseparable from its North American congener, Least Sandpiper, in all plumages, yet postural differences are often cited as good first clues. Our Long-toed is exhibiting the upright posture usually associated with this species, though not the long-necked appearance often noted. Leasts display a more hunched, compact posture, even when alert. And though Leasts are longer-toed than all other calidridines except Long-toeds, Long-toed's toes and tarsus are longer than its bill, a feature unmatched by Leasts and readily apparent in our photo.
A) Good photo, easy bird
Now that we know how the so aptly named Long-toed Stint got its name, let's turn our attention to our first quiz bird, the Bow-billed Tringine. I can remember as a novice birder flipping through the shorebird section of a field guide despairingly feeling I was comparing apples to apples. Only three of all the waders stood out from the flock, and what so obviously distinguished these, of course, was their outrageous bill shapes, so different from all the rest. My novice brain immediately sprung these three to the top of my most-wanted shorebird list.
I missed the Spoonbill Sandpiper in Barrow. I didn't chase the Broad-billed Sandpiper at Jamaica Bay. This Terek Sandpiper was one of three pairs a storm with southwest winds blew in to us on Attu this past May. The Tereks were my personal best-of-trip bird. I was with the group whose leader, the shockingly good Mike Toochin of Vancouver, BC, first heard, then spotted a pair of Tereks a quarter mile away on a small island. They flushed almost immediately, before we could get good looks or alert the other groups. An hour later I was lagging behind my group, lying on my belly in two inches of water trying to fill the frame with a Wandering Tattler picking across a rock shelf. This guy walked into my viewfinder. Better to be lucky than good. I was the designated hero for the day.
A first look at this bird could suggest godwit, but none of our four godwit species has a bill this upturned, or this long relative to its leg length. . Godwits are long-legged waders with straight to slightly upcurved bills This is a short-legged wader with an outrageous bill shape. Confirming diagnostic shape and structural features is the distinctive Terek breeding plumage, the row of dark-centered scapular feathers. These Tereks were so cool I know I will chase the next Spoonbill or Broad-billed.
B) Good photo, difficult bird
If we start on this bird with shape and posture, taking plumage into account only secondarily, we are left with the disquieting notion that this is somehow an old friend who has perhaps had cosmetic surgery and is now not quite recognizable. There's the long, stout, ever so slightly upturned bill. There's the long neck. There's the long legs, tarsus deep in the water. There's the long primary extension with wings extending just to the tip of the tail. There's the horizontal posture which, even though not upright, conveys a sense of alertness. We can almost imagine our bird beginning to pump up and down as we encroach into its comfort zone.
It looks like the original tringa shorebird mold. It has to be a . . . yellowlegs, undoubtedly a Greater Yellowlegs judging from relative head/bill length. We've encroached too far! It flushes, calling loudly! Three notes. But our ear gives us the same uncomfortable feeling our eye did. Something is not quite right. The notes are all on the same pitch, not descending, and even sharper than expected of a sentinel yellowlegs. Then we see it! The in-flight plumage pattern looks like a dowitcher, all white-backed, and nothing like our yellowlegs with white tail and rump contrasting sharply with dark back.
We're on the outer Aleutians, Dorothy, and many of our familiar North American waders have an Asian congener which can show up here and look familiar . . . vaguely. It is a large part of Attu's allure that so many shorebirds are possible and that many so subtly, yet critically, test our powers of visual and aural discrimination and scramble our geographically based preconceptions - Least Sandpiper/Long-toed Stint; Spotted Sandpiper/Common Sandpiper; Bar-tailed Godwit/Black-tailed Godwit; Whimbrel/Bristle-thighed Curlew; Wandering Tattler/Gray-tailed Tattler, Greater Yellowlegs/?
It's time to check plumage characteristics. The scapulars on our quiz bird are not showing the bright white spotting we would expect on a spring yellowlegs, but rather splotchy dark streaking. The flanks are unmarked, lacking the heavy barring we would expect on a breeding yellowlegs. We have enough here, even in black and white, to distinguish this Attu vagrant as a Common Greenshank. Typically spring greenshanks are paler overall than Greater Yellowlegs with less heavy and less extensive streaking on head and breast. And of course the color slide shows off the diagnostic green shanks.
We had two very co-operative greenshanks on Attu this spring, offering a fun example of how geographic preconceptions differ. The leader at the first greenshank site was from the midwest. He eventually flushed the bird, after everyone had seen it, to show the flight differences from yellowlegs. The leader at the second bird was from Alaska. He also eventually flushed his bird - to hear it call and confirm it was not a Nordmann's Greenshank.
C) Bad photo, easy bird
In past quizzes I've tried to avoid the bad photo/difficult bird combination, but we're out on the edge this time anyway, so let's go for it. On a typically gloomy, low-light Attu day this bird was a long ways off and it was not doing a thing, just resting in the kelp amidst beach debris - a perfect prescription for a bad photo.
By shape our photo bird appears to be a small wader, possibly another calidridine. In fact this bird was at once the rarest of the 1999 Attu shorebirds and the easiest to identify. Even in this bad photo there are three discernible clues, one structural and two plumage. Strain your eyes, look at that tail, and ask yourself if you have ever seen a shorebird with a tail that long. Noticeable plumage characteristics are the obviously dark-centered mantle and scapular feathers and what appear to be white outer tail feathers.
Many in the group, seeing this species for the first time as a Lifer, remarked how "dove-like" it appeared, citing the dark mantle spots. Upon further consideration it seemed more the bird's shape, specifically the long extension of the tail beyond the wings, which promoted its Mourning Dove jizz. Only one shorebird shows white outer tail feathers and a tail extension longer than an eye's diameter beyond the wings. Are you on the stint page yet?
In living color Temminck's Stint is very plain, lacking any rufous feather edgings. The North American version of Temminck's, despite dark legs and its well known wing projection, is Baird's Sandpiper. These two calidridines share drab, mousy plumage, the dark-centered mantle feathers, buffy wash across the breast, and Baird's long wings seem to approximate the attenuated look of the long-tailed, short-legged Temminck's.
School's out. Bail out of that armchair and head for the sewage ponds. It's not likely you'll see our photo birds, but you're up to speed again on tringines and calidridines, and you didn't have to endure forty degree horizontal rain-mixed-with-snow to get there.