Summary (AGH): Different species of sandpiper show quite different reproductive behaviours, from how they pair up or mate (one male with several females, or one male with one female, or several males with each female) to how they long they care for the young (from very short periods to long after the young can fly). How these habits vary across a species’ range can be a clue to why these habits vary. So Least Sandpipers nesting on Sable Island, so far south of the species’ mostly arctic range, are a particularly good study system. Surprisingly, their breeding habits on Sable Island are very similar to those in the north; breeding starts shortly after the birds arrive in spring (in mid-May, with males arriving first), and females tail off their care of the brood and leave the island to migrate south sooner than males (by late June, compared with early July for males). That these patterns are apparent on Sable Island, suggests that early, quick breeding in many sandpipers is not just because of the short arctic summer, as is often suggested. One unusual feature of breeding on Sable Island was that so few chicks survived to the age when they could fly (only 40%). Intense predation from Herring Gulls, perhaps inadvertently increased by investigators, was thought to be the cause.
