Abstract Clutch reduction (the disappearance of 1 or more eggs) is often reported in studies examining avian reproductive success and has typically been attributed to nest predation. We recorded clutch reductions at 20 (11%) of 188 Piping Plover (Charadrius melodus) nests at Chaplin Lake, Saskatchewan from 2002 to 2004. Partial clutch reductions were initially assumed to be the result of predation. However, all egg disappearances at three nests we monitored using video cameras were due to accidental removal by incubating parents. Our observations suggest that accidental removal may occur more frequently than expected in alkaline environments, and are likely misclassified as losses due to predation.