Oct. 28, 2013 — The behaviour of semipalmated sandpipers (Calidris pusilla) feeding during low tide in the Bay of Fundy, New Brunswick, surprised Guy Beauchamp, an ornithologist and research officer at the University of Montreal's Faculty of Veterinary Medicine. While individuals on the periphery remained alert and used short pecks to feed on the mudflats, birds in the middle of the group relaxed their vigilance and fed on a different resource. The more peripheral group members were effectively used as sentinels for the others.
Two observation seasons were needed to confirm this never-before-documented behaviour. The phenomenon attracted the attention of Britain's Royal Society, which has just published the results of Beauchamp's research in the most recent edition of its Biology Letters. "Both foraging modes are easy to distinguish," Beauchamp explained. "In the first case, the birds keep their heads upright while pecking at their food rapidly; they are on the lookout for predators. In the second case, their heads are kept low while they scrape the mud in search of tiny organisms."