Tuesday, August 31, 2010

Buff-breasted Sandpiper

Sunday afternoon Dave B. e-mailed that he found a small flock of Buff-breasted Sandpipers east of Faribault.  Never having "ticked" this species on my Rice County list, I somewhat belatedly set out in search.  I easily discovered this single bird feeding in a sod farm where the original flock was reported.  This sandpiper often prefers dry, short-grass habitat.

Buff-breasted Sandpipers breed sporadically across the western Canadian and Alaskan Arctic shores and into western Arctic Asia.  The Asian birds presumably migrate with the North American ones to the pampas of Argentina, Uruguay, and Paraguay.  They migrate over the central United States. The species seems to be fairly picky about its habitat.  I have observed this sandpiper only about a half dozen locations.  Erika and I saw them regularly in Louisiana, but only in the same well grazed pasture in Cameron Parish.  We encountered them on a grass DC 3 landing strip in the Amazonian Ecuadorian jungle. I saw them twice in South Dakota, once along a weedy drained shoreline and once in grazed pastureland.  Finally, I have found them twice in Minnesota, both times in sod farms.

The first time I saw these birds in South Dakota we found a flock of several hundred in May.  Despite their migrating, the males were already displaying.  Buff-breasted Sandpipers have bright white under-wings.  Males display by extending one or both wings, trying spasmodically to flag down the interest of females.  This species are the only North American breeding shorebird to breed on leks.  Males defend small display sites.  Females pick the sexiest mate and then nest elsewhere without male assistance.  Check out this video.

Once abundant, Buff-breasted Sandpiper numbers have greatly declined since the late 1800s.  Grassland habitat in the United States and in southern South America has gone under the plow.  Before the Migratory Species Act, this sandpiper was also commercially hunted.  Buff-breasted Sandpipers are usually tame and have the unfortunate habit of returning to wounded flock members.  Despite legal protection, recent surveys suggest the species is still declining.  The Handbook of Birds of the World estimates the total world population to be no more than 25,000.  In contrast, the Stilt Sandpiper, which has a similar migration route but different habitat preferences, enjoys as many as 100,000 individuals.  (I am not exactly sure how these estimates are made.)

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