are found on shores and in wetlands around the globe, breeding on the Arctic
tundra to more temperate climes. This adult Spotted Sandpiper (left)
typifies the latter group: it breeds along river and lake shores across
temperate North America.
Sandpipers are a highly diverse family which include the ground-dwelling snipes and woodcocks to the highly pelagic Red Phalarope Phalaropus fulicarius. Biochemically they seem to have arisen from a single ancestor but underwent an explosive evolution in the early Tertiary after a great wave of extinctions in the late Cretaceous period (Piersma 1996). Today, the wide variety of sandpipers, and the close relationships of many, present numerous identification challenges. The identification literature alone is impressive. Further, the beautiful patterns and colors on juvenal-plumaged birds are among the most striking in the world, while the striking breeding plumage feathers serve to camouflage adults on their breeding grounds on the arctic tundra. Many of these arctic breeders spend the non-breeding period well south of the Equator, brightening the lives of birders in the austral summer (our winter).
|Sometimes as I walk along a beach and watch the skittering sandpipers
chasing the waves, I think about just how far each individual bird has
traveled to reach the spot that it and I share the same sand. I suppose
that is a bit too metaphysical for some birders but it was, for example,
essentially the premise of Last of the Curlews, the personalized
and fictional story of the last Eskimo Curlew on earth (Bodsworth 1954).
In this light, I rather like the photo above. It shows an adult Little Curlew — the closest relative to Eskimo Curlew left on earth — standing on a beach and apparently contemplating its next long flight over the crashing surf and endless Pacific Ocean to its final destination. Little Curlew has one of the longest migration routes — from northeast Siberia to Australasia — and although it is not on the edge of extinction, its numbers are rather small (e.g., ~200,000; Piersma 1996). In truth, this photo documents one of the very few Little Curlews to reach North America, a vagrant bird that appeared in California during the autumns of 1984, 1988, 1993 (all of those years it visited the Santa Maria R. mouth in n. Santa Barbara Co.) and finally in fall 1994 on Carmel State Beach in my home county (where this photo was taken).
|Among the challenges of shorebirding is to learn the three plumages
of each migratory species while keeping in mind the distances and directions
they travel. Consider the Little Stint (next three photos), a widespread
breeder on Arctic tundra in Eurasia. Adults breed and migrate in a colorful
(=breeding) plumage (below, upper left), youngsters migrate during
their first autumn flight south in patterned juvenal plumage (below,
lower left), and then both molt into a plain basic (=winter) plumage
when they reach their wintering grounds.
Basic plumage contains shades of gray or brown, essentially unmarked, against mostly white underparts. But both alternate and juvenal plumages can be quite colorful, especially in Calidris sandpipers, and separating breeding-plumaged adults from youngsters in juvenal plumage in early fall migration (particularly July-Sep) can be difficult. Yet this is the time when wader-watching is at its peak, and the chance of finding vagrants is the highest. The set of photos below compare these age classes.
|Above is a Least Sandpiper in juvenal plumage. That plumage
is colorful with many of the upperpart feathers showing multiple colors.
Many are black-centered with rusty, white, or orange edges. Adult feathers
can be equally colorful, so the key is to locate the upperwing coverts,
highlighted in yellow in the small photo to the right. An enlargement of
that area shows tracks of feathers that are just as patterned and colorful
as the rest of the upperparts. The two yellow arrows point to two of the
feathers in the greater coverts: each is blackish-centered with orange
edges and white tips. The feathers are fresh and the colors well demarcated.
The row of feathers just above these (median coverts) is similar and so
are the rows of small lesser coverts that can be seen. However, in the
upper left of the close-up shot are some large scapular feathers that overlap
and cover most of the lesser coverts, and in the large photo of the whole
bird, you can see many scapular and back feathers dominating the upperparts.
It is critical to locate the actual greater and median coverts to be able
to age this individual as a hatch-year bird in juvenal plumage.
Below in a Dunlin in full alternate plumage. That plumage is also very colorful with the upperpart feathers showing multiple colors. Some feathers look red-centered with black subterminal bands and white tips. [Incidentally, this Dunlin is of the race pacificus, which has the reddest upperparts of any of the races and used to be called "Red-backed Sandpiper."] In Dunlin, the underparts are also colorful (large black belly patch) in adults, making ageing easier, but not all Calidris have colorful underparts in alternate plumage. Rather, locate the upperwing coverts: again they are highlighted in yellow on the small photo to the right. In the enlargement below, the lefthand yellow arrow points to the row of median coverts and the righthand two arrows point to the great coverts. Note that each feather in the median and greater coverts is NOT colorful — it is plain gray with a little duskiness along the shaft, and each feather is very worn. This is because adults in alternate plumage retain the upperwings coverts from basic (=winter) plumage instead of molting them in the spring. So in spring, summer, and during fall migration, adults in a colorful alternate plumage have very dull, worn, and gray upperwing coverts. If you can locate and identify the upperwing coverts, you can easily age shorebirds in fall migration. Beware, however, that under many circumstances the big scapular feathers entirely overlap the coverts, so it can take a little bit of time to see the underlying feathers (e.g., in the adult Little Stint from Barrow, above, the scaps entirely cover the upperwing coverts).
|The ability to correctly age sandpipers in migration is critical for identification between similar species, especially in the Calidris stints. Yet many of the various groups of sandpipers are rather easily recognized. Some of these groups are shown in the gallery of four shots below. Can you recognize these groups?|
|There are six curlews in the genus Numenius, easily recognized by their long decurved bills (this includes Whimbrel N. phaeopus but excludes the likely extinct Eskimo Curlew N. borealis). In the matrix here, these are represented by North America's Long-billed Curlew (upper left). There are four species of godwit in the genus Limosa, also easily recognized by their long upturned bills, and represented here by America's Marbled Godwit (upper right). A slightly larger and more diverse group are the nine species of Tringa sandpipers, most of which have longish legs and medium-length, usually straight bills. One example is Marsh Sandpiper of Eurasia, some of which undertake a long migration from high latitudes to winter near the Equator in Africa (the one shown here, lower left, is in basic plumage in Kenya). There are also a number of genera with just one or two species — ranging from tattlers to turnstones to dowitchers — and including among them the monotypic genus Bartramia, Upland Sandpiper of central North America (lower right). It is long-legged and long-necked but short-billed, and undertakes a few long migration route to southern South America. On its breeding grounds it is often found standing atop fenceposts (as shown).|
|One of the larger groups within the sandpipers are the 20 snipes in
three genera, 17 of which are within Gallinago. Snipes are
secretive waders, probing soft soils for invertebrates and often not noticed
until flushed. The North American example is Wilson's Snipe (right),
here shown unusually visible atop a fence post on its breeding grounds.
Snipe inhabit all the large continents (North America, South America, Eurasia,
Africa), as well as some islands (Madagascar, New Zealand), and many are
difficult to separate from each other. Many are crepuscular, as are the
8 species of woodcock, genus Scolopax. Males have elaborate courtship
flights at dusk or dawn but they are otherwise very secretive. One at high
elevations on Luzon I., Philippines, was just recently discovered to science
(Bukidnon Woodcock S. bukidnonensis). In North America, the American
Woodcock is confined primarily to the eastern U.S., and only one has
reached California (shown below).
|All in all, sandpipers in this family, combined with plovers [Charadriidae],
are often termed "shorebirds" or "waders" and are among the most popular
set of birds for field observers. This is probably because of their lengthy
migrations, producing strong seasonality in local occurrences, and the
challenges in sorting out the various species and plumages, always keeping
in mind the possibility of a rare vagrant. It has often been a joke among
American birders traveling overseas that if they run into another birder,
one can tell their nationality by their interests. If the observer is keen
on raptors, he or she is apt to be Scandinavian. If the observer is searching
out little brown jobs in the forest undergrowth, that's an American. But
if the observer has eyes only for the waders — that's a Brit. Of course
this is a wild exaggeration, yet it does hold a grain of truth.....
The migrations and plumages of the Scolopacidae are, indeed, fascinating. This flock of basic-plumaged Gray-tailed Tattlers (below) were on Heron I., a tiny speck of an atoll island on Australia's Great Barrier Reef. They had flown there all the way from their breeding grounds in northeast Asia, a distance of ~5000 miles. This feat alone rates among the wonders of the avian world.
Photos: The adult Spotted Sandpiper Actitis macularius was digiscoped at the Carmel R. mouth, Monterey Co., California, on 15 Aug 2004. The juvenal Sharp-tailed Sandpiper Calidris. acuminata was at my local patch, Moonglow Dairy, Monterey Co., California, on 22 Sep 1986. California's first Terek Sandpiper Xenus cinerea was on Carmel State Beach in Sep 1988; my photo was on 6 Sep 1988; the State's first Bristle-thighed Curlew Numenius tahitiensis was at Crescent City on 16 May 1998. The Little Curlew Numenius minutus was on Carmel State Beach, Monterey Co., California, on 9 Sep 1994. Ed Greaves photographed the adult Spoon-billed Sandpiper Eurynorhynchus pygmeus on Attu I., w. Aleutians, Alaska, on 31 May 1986. The adult Red-necked Stint C. ruficollis was at Moss Landing, Monterey Co., California, on 14 July 2001. The adult Little Stint C. minuta was photographed by Peter J. Myers at Barrow, Alaska, on 28 June 1976, where it represented a first North American record at the time; the juvenile was at Moonglow Dairy in Sep 1985 (many California birders chased this rarity, the 2nd State record at the time), and the basic plumaged Little Stint was at Lake Nakuru, Kenya, in Nov 1981. The juv. Least Sandpiper C. minutilla was at Carmel R. mouth, Monterey Co., California, on 15 Aug 2004. The adult Dunlin C. alpina was at Salinas R. mouth, Monterey Co., California, on 7 May 2004. The Long-billed Curlew Numenius americanus was digiscoped at Moss Landing, California, on 2 Jan 2004. The Marbled Godwit Limosa fedoa was on Elkhorn Slough, California, on 12 Sep 1993. The wintering Marsh Sandpiper Tringa stagnatilis was at Lake Naivasha, Kenya, in Nov 1981. The adult Upland Sandpiper Bartramia longicauda was at Winnipeg, Manitoba, Canada, in July 1988. The adult Wilson's Snipe Gallinago delicata was at Diamond Valley, Alpine Co., California, on 20 June 1999. California's first American Woodcock Scolopax minor was sitting in a flowerbox at Iron Mt. Pump Station, San Bernardino Co., on 9 Nov 1998. My photos were the only ones taken of this exceptional vagrant, and I was the last person to see it. It was especially meaningful to me since "American Woodcock" is my officially bestowed "bird name" from the "old days" back in the 1970s. I never thought I'd see one in my home state. Finally, the flock of Gray-tailed Tattler Heteroscelus brevipes was on Heron I., Great Barrier Reef, Australia, in Sep 1983. All photos © Don Roberson, except those attributed to Ed Greaves, John Sorensen, and P.J. Myers who hold those copyrights; all rights reserved.
Family book: rating
Hayman, Peter, John Marchant & Tony Prater. 1986. Shorebirds: An Identification Guide to the Waders of the World. Croom Helm, London.
This book covers all the Charadriformes — not just shorebirds (waders to Brits) — and so includes plovers, stilts, avocets, jaçanas, thick-knees, and pratincoles. It is not a "family book" per se, since its focus is on identification problems, but it does include sections on "habits" and migratory or seasonal "movements." Breeding biology and similar topics are not covered here. However, the quality of the identification text more than makes up for this "defect", and adding broader topics would have made for a very fat book. John Marchant gets special credit for the text — an upgrade from his 1977 guide (with Prater & Vuorinen) — which surveys the literature well and is based on much original research. The book does rely on Hayman's paintings for illustrations and while they are generally good, I think that photos are a necessary requirement when dealing with the subtleties of shorebird identification. So use this book as an introduction to these families — and the identification problems that exist — but rely on other texts for state-of-the-art details.Other literature cited or recommended:
Birdlife International. 2000. Threatened Birds of the World. Barcelona & Cambridge, U.K., Lynx Edicions & Birdlife International.
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