Do nest exclosures affect the behaviour of Piping Plovers (Charadrius melodus melodus) and their predators?

Abstract

Predators are a threat to many ground-nesting shorebirds; however, nest exclosures are a tool used by managers to reduce nest predation. Others have found that nest exclosures increase hatching success, but there has been concern that they may also increase adult mortality and nest abandonment. We examined the effects of nest exclosures on the behaviour of incubating Piping Plovers (Charadrius melodus melodus Ord, 1824) and their predators on nesting beaches in eastern Canada. Using a combination of field observations, video monitoring, and an artificial nest experiment, we found that adult incubation behaviour did not differ between exclosed and unexclosed nests. Predators, however, visited exclosed nests more often than unexclosed nests and spent more time in the vicinity of exclosed nests than unexclosed nests at one of our sites. These findings suggest that concerns over increased adult mortality and nest abandonment are plausible and require further study.