The Spring bird migration is on and I hadn’t made time to visit Hornsby Bend. That changed last Thursday when we drove the lanes for an hour or so in the evening. Sticking to the ponds, rather than exploring the trails along the Colorado River, we got perhaps 20 species in an hour or so. But, perhaps, quantity made up for the usual diversity we expected at this time of year. There were rafts of Shovelers (Anas clypeata), bigger flocks of Spotted Sandpipers (Actitis macularia) and Coots (Fulica americana) than I’d ever seen before. There were Blue-winged Teals (Anas discors), Glossy Ibis (Plegadis falcinellus), Killdeer (Charadrius vociferus), Red-winged Blackbirds (Agelaius phoenicus), and one of my favorites, the Scissor-tailed Flycatcher (Muscivora forficata). But the find of the evening was a long-legged Stilt Sandpiper (Calidris himantopus), a species I had never seen before. It took a while to identify it but the blacking green legs finally gave it away (distinguishing it from the Lesser Yellowlegs [Tringa flavipes]). It is lucky that this species is no longer hunted—the bird we saw ignored our presence altogether and continued to feed just a few meters away. It still had a long way to go, to the Arctic to breed later this Summer.
Little seems to be known about this rather odd delicate-looking bird in spite of the somewhat illustrious history of its study [1]. (It was first scientifically described in 1826 by Charles-Lucien-Jules-Laurent Bonaparte, son of Lucien Bonaparte and, thereby, nephew of Napoleon. Charles L. Bonaparte [the form of the name he usually used, at least in scientific publications] lived in the US from 1822 to 1828 where ornithology seems to have been his major interest. In 1824 he even tried to get the unknown John James Audubon accepted into the Academy of Natural Sciences in Philadelphia [the most prestigious such body in its time] but this was resisted by the prominent ornithologist, George Ord, who had developed a personal animosity to Audubon. [Audubon never made it into the Philadelphia Academy though he was elected to the Royal Society of London in 1830. In 1840 Bonaparte became Prince of Canino and Musignano in Italy, but was expelled from that country in 1849 for his political activities in support of the Italian nationalists then attempting to forge a united nation. He finally became director of the Jardin des Plantes in Paris, dying in 1857.)
Over the years this sandpiper has been called Bastard Yellowlegs and Mongrel (because of suspicions that it was a hybrid) besides Stilted Sandpiper, Long-legged Sandpiper, and Frost Snipe [1]. Bonaparte’s description of the bird captures its uniqueness—and its beauty:
“TRINGA HIMANTOPUS, Nobis. Bill much longer than the head, sub-arched; legs very long, toes semipalmate; rump white, banded with black; tail even, gray, middle feathers longest, lateral white internally and along the middle.
Total length nearly nine and a half inches. Bill, one and five eights. Tarsus one and three quarters. Naked space of the tibia, one and a quarter.
This new species, which I shot from a flock at Long Branch, New Jersey, in the middle of July, is very remarkable for its anomalous characters. It connects still more closely with the other Tringae with subarched bills, the two genera Numenius and Tringa, since to other common traits, it unites the semipalmated toes; indeed instead of placing it in the head of Tringa, we should place it at the last of Numenius, was [sic] it not for its long, slender, and delicate legs and toes. As a species, in point of form, dimensions, and especially of plumage, this bird resembles greatly Tringa subarquata of Temminck, (Numenius afticanus, Lath.) from which it is, however, eminently distinguished by its still longer and semipalmated feet, in which character only it resembles Tringa semipalmata, Wils. It cannot even at first sight be mistaken for any other Tringa, differing widely from each and all, and resembling much more in general appearance a Totanus than a Tringa.
This bird, together with the Tringa semipalmata, forming my subgenus Hemipalmata, I here subjoin a distinctive phrase for the latter bird [2, 157 -158].”
Since 1973 the species has been subsumed under the genus Calidris, though earlier it had been the sole surviving member of the species, Micropalama [1]. The long legs, partly webbed toes, and a long bill, though uniquely combined in this species, are all common traits among the Calidris.
Stilt Sandpipers breed exclusively in the low-arctic and subarctic regions of North America and winters mainly in central South America (including Bolivia, Brazil, Paraguay, and Venezuela), though some are found throughout Mesoamerica and even along the Texas coast. Breeding pairs are apparently monogamous and return to the same breeding territory for years, often reusing nests. Its breeding range extends from James Bay in Canada to Alaska but is probably interrupted. So little is known about the bird that its breeding has only been studied at a handful of sites in Canada and one in Alaska. Information about its migration and wintering behavior is even more scanty. One interesting fact is that many of the birds interrupt their Fall migration in northern South America to molt flight-feathers before continuing on to the winter feeding grounds further south. It has always been rare but that may partly be because it was often confused with other species. Historical patterns of population change are simply not known and it is not surprising that the species is found in the IUCN-World Conservation Union’s North American Watchlist (though not yet in the list of Threatened Animals) [3, 286]. The main threats may be degradation of nesting habitat due to overgrazing by other species (Canada Goose [Branta canadensis] and Snow Goose [Chen caerulescens]) which opens up marshes and leaves the young exposed to predation, as well as winter habitat modification in South America, particularly the northern coast of Venezuela [1]. At one study site in Alberta, Canada, the breeding population has declined by over 70 per cent since the 1960s.
In Austin it’s a fairly rare migrant and we were lucky to see it. And the Spring migration is far from over. There will always be surprises at Hornsby Bend even if we don’t manage to go elsewhere. But it’s hard not to think of a trip to the north Texas coast.
[1] Klima, J. and Jehl Jr., J. R. 1998. “Stilt Sandpiper.” The Birds of North America 341: 1 -19.
[2] Bonaparte, L. C. 1826. “Further Additions to the Ornithology of the United States; and Observations on the Nomenclature of Certain Species.” Annals of Lyceum of Natural History of New York 2: 154 -161.
[3] Sibley, D. A., Elphick, C., and Dunning Jr., J. B. 2001. The Sibley Guide to Bird Life and Behavior. New York: Alfred A. Knopf.
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