Sandpipers. Ugh. Some birders go to great lengths to avoid them. Folks brave bugs and brambles to glimpse a warbler. But sandpipers? Forget it. Not worth the effort. They all look alike.
Naturally, that’s the thing I like most about them. If it were easy, anybody could do it. I accept the challenge. Those little twerps are not going to get the best of me.
Except, they do. I have a confession to make — please keep this between us. Sometimes, I’m wrong. When we see them in late summer, young birds with their new plumage look brighter than their tired, worn-out parents. There can be considerable color variation between birds of the same species. Sometimes, I’m not exactly sure what that odd-looking bird is.
Unfortunately, I’m supposed to know. I guide professionally and people are counting on me. As I peer through the scope, trying to confirm the presence of an unusual sandpiper among all those semipalmated sandpipers, I feel beads of sweat forming on my forehead. Uh-oh.
So I go back to the advice I offered in this column two years ago. Everything is a semipalmated sandpiper, unless it isn’t. There may be thousands of sandpipers on a Maine mudflat in mid-August, but most of them are the same. Most are semipalmated sandpipers. Most of the rest are least sandpipers. The two birds look similar, except that the latter is slightly smaller, slightly browner and has slightly yellowish legs. Once you’ve learned the difference between these two, the rest get easier to identify. These two are in a group of small sandpipers collectively called “peeps” because of the sounds they make while roaming the mudflats.
A third peep, the western sandpiper, is very similar, but it generally bypasses Maine on the way to its wintering grounds in Florida, so we only have to worry only about the first two. However, there are two other ever-so-slightly larger peeps sharing the beach, just to make things interesting.
White-rumped sandpipers are usually present in any large flock of peeps in August. They are bigger than semipalmated sandpipers, but just barely. The size difference wouldn’t be noticeable if there was only one bird on the beach, but standing among dozens of its cousins, the white-rumped looks bulky. Because its legs are longer, it also tends to stand a little deeper in the water along the edge of a mudflat. Most sandpipers have a black line that bisects a whitish rump. The white-rumped sandpiper doesn’t. This is seldom a helpful field mark because the full white rump only shows when the bird is flying, and often not even then.
What does help is this: The wings are longer than the tail. When a slightly larger peep appears, I look to see if the folded wings stick out beyond the tail, especially if the wingtips are long enough to cross behind the bird. If so, it’s a white-rumped sandpiper.
Unless it isn’t. Baird’s sandpipers are the same size and also have wings longer than the tail. These are grassland prairie birds and most migrate through the central states, but not all. Enough find their way into Maine that they are a reasonable possibility on any day of shorebirding. When encountering a suspiciously larger peep, check to see if the wings are longer than the tail. Then check the flanks under the wings. White-rumped sandpipers have speckled spots under the wings. Baird’s don’t. Baird’s have shorter legs and prefer dry land. White-rumps like to get their feet wet.
Fortunately, other sandpipers are much larger than the peeps. Pectoral sandpipers may show up on the beaches, but solitary sandpipers prefer inland mud puddles, and stilt sandpipers are more apt to work the edges of pools.
Many other shorebirds on the mudflats are all noticeably larger than the peeps. These include dunlin, ruddy turnstones, sanderlings, red knots, dowitchers, yellowlegs, and several species of plover. They are distinctive enough that identification is not particularly difficult. Once you’ve mastered peeps, you’ve mastered shorebirding.
Lindsay Tudor is the shorebird biologist for the Maine Department of Inland Fisheries and Wildlife. She reports that biologists from multiple groups are currently banding and attaching tracking devices to shorebirds in order to better understand their movements in Maine. Downeast birds are sporting dark green leg flags on their left legs and color bands on their right. Birds captured in southern Maine have dark green leg flags with alphanumeric codes. Observations can be reported at www.bandedbirds.org … if you dare.
Bob Duchesne serves as a Maine Audubon trustee and vice president of its Penobscot Valley Chapter. Bob developed the Maine Birding Trail, with information at mainebirdingtrail.com. Bob can be reached at firstname.lastname@example.org.