CWF Receives Grant to Study a New Piping Plover Predator Exclosure Design

Earlier this spring, CWF received a grant from The Boston Foundation to study a new predator exclosure design to assist with piping plover recovery.  Exclosures or nest “cages” have been used over the past several decades to protect plover eggs from predators such as red fox and crows. Although nest exclosures greatly increase hatch success, they can also increase the likelihood of an adult being killed by a predator. Unfortunately, over the years, New Jersey has struggled with high adult mortality associated with the traditional round exclosures. 

Starting several years ago, New Jersey Fish and Wildlife began experimenting with a novel triangular design. These exclosures (pictured) are also outfitted with wings to make it harder for mammalian predators to move around the exclosure, as well as spikes to prevent perching by avian predators. Although it had only been used on a limited basis up until this year, the new triangular design showed promise in reducing adult mortality of piping plovers.

This breeding season, thanks to the grant, all the partners conducting piping plover management in New Jersey – Conserve Wildlife Foundation, New Jersey Fish and Wildlife, U.S. Fish and Wildlife Service, and National Park Service – are using the new design. Deployment is being done on a random basis in order to compare exclosed vs. unexclosed nests. Furthermore, results will be compared to previous usage of traditional round exclosures. Field cameras are being placed at each nest to better understand how the new design works when predators are present or potentially how they are not effective. 

Although hatch results and any mortality events associated with the exclosures will be known in about another month, full analysis of the data, including past exclosure use, is not expected to be completed until early next year. If the results are positive, the hope is the new design could be used throughout the piping plover’s Atlantic Coast range, although the immediate goal is to bolster New Jersey’s declining population. 

Conserve Wildlife Foundation is proud to be the first recipient of a grant from The Boston Foundation’s new grant initiative, tentatively a 5-10 year effort, to benefit piping plover conservation.