The upland sandpiper was "bird of the week" one year ago this month, and this column described the bird's qualifications. These included a bit of trivia, that this is the only species whose common English name begins with the letter "U." Other better attributes were cited, including birder Dave Lambeth's assessment of the bird's occurrence in our area. "Seems to be very local," the dean of area birders said.
That is one reason for caution when I heard what I thought might be an upland sandpiper earlier this year. A relatively uncommon species two years in a row, I wondered. In habitat that's not really ideal? That seemed unlikely.
On the other hand, the sandpiper makes a distinctive sound otherwise unknown in the bird world. It's often referred to as a "wolf whistle." Yes, the label comes from its resemblance to a whistle associated with human males. The sandpiper's call is more complicated, though; as it includes other chirps and calls that make it more varied than the noises most humans are capable of making. It's been called "ethereal" and "otherworldly."
When I shared my caution with Lambeth, he essentially said, "Trust your ears. What else could it be?"
I also began a search for the source of the sound. This proved a little challenging. Upland sandpipers are masters of camouflage, lacking any distinctive plumage. The birds betray themselves in ways other than their song, however, with behaviors ordinarily seen only among birds that occur in wetland areas, the birds known collectively as shorebirds. In fact, upland sandpipers are closely related to this group of birds. The term sandpiper shows that, even though this particular sandpiper is the only member of its genus, another item of trivia noted in last year's column.
The upland part of the species name suggests that it seeks habitat other than that used by other shore birds. It frequents dry prairies, a preference that made it abundant on the Northern Plains in the pre-settlement era. The advance of agriculture had an impact on habitat, and hunting for the restaurant trade had an impact on the population of upland sandpipers.
The species has proven adaptable, however, making itself at home in mixed habitats that include grass and cultivated fields. I found this week's upland sandpipers in a soybean field, three of them for sure, and perhaps as many as five, based on vocalizations from points away from the birds in view. A family group, Lambeth posited when I shared this news with him, vocalizing and displaying to alert one another of an intruder in their territory. I'd be that intruder.
In addition to their calls, the birds showed off their shorebird-like flight, including an acrobatic circle-and-plunge technique. Alighting, the birds raised their wings, another shorebird characteristic, but unlike most shorebirds, the upland sandpipers perched on tree branches and overhead wires, the better to evaluate the intruder and his intentions. All of this pleased the intruder, who is happy to count upland sandpipers on his list of yard birds, even if the definition of "yard" here includes adjoining shelterbelts, powerlines and soybean fields.
But the real clincher came from an unexpected source, a book called "Birds of La Plata" by William Henry Hudson, a founding member of Britain's Royal Society for the Protection of Birds. Hudson was the son of American parents who started a ranch on the Argentine pampas, and as a youth in the 1870s, he made a detailed study of bird life there. Later Hudson moved to Britain and began a literary career, writing extensively about birds and landscapes.
Like many North American species, the upland sandpiper actually spends most of the year in South America, up to months in this case, and I wondered if Hudson might have encountered the upland sandpiper. He had, though he called it Bartram's sandpiper, a name abandoned nearly a century ago. Here's what he had to say in an essay first published in 1889. Remember as you read that summer in Argentina occurs when winter holds sway here.
"It begins to arrive as early as September, coming singly or in small parties of three or four; and, extraordinary as the fact may seem when we consider the long distance the bird travels, and the monotonous nature of the level country it uses as a 'feeding area' it is probable that every bird returns to the same spot year after year; for in no other way could such a distribution be maintained, and the birds appear every summer evenly sprinkled over so immense a surface."