Curlew Sandpiper (Calidris ferruginea) Science Article 2
In several wader species that breed in the High Arctic, birds appear in pairs immediately after arrival at their breeding grounds (see references in Meltofte, 1985). It is generallyunknown, however, whether pairs were formed shortly after arrival at the breeding site or if the birds paired somewhere in the winteqr uarters or during spring migration. The latter is the case with many ducks and geese.
PETER FRODIN et al., ARCTIC, VOL. 47(2) p. 142-144