Buff-breasted Sandpipers typically arrive in the NWT in mid-May and leave the breeding grounds from late July to early September for their wintering grounds.
Buff-breasted Sandpiper habitat use varies throughout the breeding season on the tundra. Breeding displays usually start on dry, unvegetated, snow-free areas and move to moister grass and sedge meadows as the season progresses. Nests are typically in sedge patches near dry display areas and close to water sources, or in wetlands near large waterbodies or rivers. Foraging is usually on sparsely vegetated areas, especially along the banks of streams and rivers.
The Buff-breasted Sandpiper is a polygamous species. This means one male courts and breeds with several females. The Buff-breasted Sandpiper is the only North American shorebird with a lek mating system. A lek is when several males gather to perform competitive displays that entice females to come watch and check out potential mates.
While most male shorebirds stop displaying once nests are established and the breeding season progresses, Buff-breasted Sandpiper males display to females already on established nests and even while on migration.