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When thinking of a sandpiper, the first image that comes to mind is a bird with a long bill that feeds by probing sand along coastal shores. Buff-breasted Sandpipers (Calidris subruficollis) do not fit that profile. They are rarely found on sandy shores, they have short bills, and feed like plovers — above ground using their sight to locate prey. This species is so unique it was in its own genus, Tryngites, until 2013.
The Buff-breasted Sandpiper is a medium-sized sandpiper (18cm – 20cm long) with a short and dark bill, yellow legs and distinctive year-round silvery-white underwing feathers, while buff on the face and belly. Photo: Brad Winn
Perhaps the most unique trait is its breeding behavior, once featured in the BBC series “The Life of Birds”, hosted by David Attenborough. Buff-breasted Sandpiper is the only Scolopacidae in the Americas to mate on communal display grounds known as “leks”. Males dispersed on a lek defend a small territory from which they perform their breeding displays. It is a beautiful sight in the Arctic tundra! From a distance you have the impression you are seeing little, tiny mirrors reflecting the sunlight. On closer inspection, you realize these reflections come from the slivery-white underwings of males displaying one or both wings for females that fly above or are closely watching males from the ground. After selecting a male, the females leave to build nests, incubate, and raise chicks by themselves.
Another unusual behavior exhibited by the species is the low fidelity of both males and females to breeding sites. Shorebirds tend to be faithful to the area where they breed, with high return rates year after year. Buff-breasted Sandpipers do show high fidelity to the South American grasslands where they spend the non-breeding season, but not to the tundra sites in which they breed. This low fidelity combined with a dispersed and sporadic distribution on the breeding grounds has made it difficult for shorebird biologists to determine its population size with precision, data that is essential for conservation action.
The raised wings of a male Buff-breasted Sandpiper is a beautiful sight. Photos: Shiloh Schulte.
Even without knowing precisely their population size, we do know they have suffered a steep population decline within the last century. The population went from hundreds of thousands or millions in the early 1800’s to an estimated 35,000 to 78,000 birds. This decrease is attributed largely to commercial hunting in the central plains of the United States during the late 1800’s and early 1900’s. The species is currently considered as ‘near threatened’ on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species and has been included in the official threatened species list of several countries in the Americas.
Over the last twenty years, Buff-breasted Sandpipers have been studied throughout their annual cycle to learn more about their migration routes, sites, and the threats they face. The species migrates through the interior (Midcontinent) of the Americas when flying between the Arctic tundra where they breed (June – August) and the Pampa grasslands in the southern cone of South America where they spend the non-breeding season (October – April). Their migration follows a hop and skip strategy where birds fly smaller distances and stop at many sites on their journey, as opposed to a jumping strategy where birds fly large distances and stop at only a few sites, but for a longer period to accumulate large fat reserves.
During the southbound journey, Buff-breasted Sandpipers migrate through the western prairies of Canada and the United States, stopping at Saskatchewan, North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, and Texas. In South America, birds stop mainly in Colombia, Bolivia, and Paraguay before reaching the coastal Pampa grasslands in Brazil, Uruguay and Argentina. Northbound migration follows a similar pattern, though birds will make fewer stops in South America. In North America, they use similar stops in the Great Plains before flying to the Arctic. At all of these sites, Buff-breasted Sandpipers are dispersed over a large area but occasionally can be found in flocks of several hundreds to a thousand.
Map of example northbound and southbound tracks for a Buff-breasted Sandpiper.
This migration strategy, i.e., spreading over an extensive area at stopover sites instead of gathering in large congregations at a few sites, has conservation implications for Buff-breasted Sandpipers, which is further complicated by the land use at many of these sites. They are working lands – lands that produce food for human communities. Fortunately, depending on the practices adopted, the two can co-exist within certain productive systems. Conservation strategies for the species must include site protection, implementation of practices that benefit both the species and producers, development of policies that benefit the species, and flyway-scale collaboration.
During the last several decades, several sites have been identified as important along the migration route of the Buff-breasted Sandpiper. Currently, nine of these sites are part of the Western Hemisphere Shorebird Reserve Network (WHSRN). In North America the Flint Hills and Rainwater Basin are Landscapes of Hemispheric Importance for the Buff-breasted Sandpiper, and in South America, Barba Azul Nature Reserve (Bolivia) and Sabanas de Paz de Ariporo y Trinidad (Colombia) are Sites of Regional Importance. At some sites, local collaboration between landowners and conservation partnerships has led to the development and implementation of practices that combine production and habitat conservation. Scaling up successful collaborations such as these to a flyway approach is necessary to guarantee habitat conservation for the majority of the species’ population.
Left: Small flock of Buff-breasted Sandpipers with grazing cattle. Photo: Monica Iglecia. Right: Flock of Buff-breasted Sandpipers at Lagoa do Peixe National Park. Photo courtesy of Marco Silva.
The Midcontinent Shorebird Conservation Initiative (MSCI) provides a flyway framework to guide conservation actions for shorebirds, including Buff-breasted Sandpipers. Its strategic framework was built with participation of 242 institutions representing 18 countries and territories of the Americas. It provides a strong means to enhance collaboration and promote conservation of shorebirds and habitats along these countries. The Buff-breasted Sandpiper is one of the focal species benefitting from this new hemispheric initiative that will be launched in late 2023.
With conservation approached at different scales, the future is looking brighter for the Buff-breasted Sandpiper. Conservationists, local communities, and landowners are sharing their interests and needs while working together at the local scale. Meanwhile, the MSCI will promote conservation at the flyway scale. With the engagement of so many stakeholders, there is hope that the species will continue to charm us with its unique behavior and displays.
Cover Photo: Flock of Buff-breasted Sandpiper. Photo: Brad Winn.
