Things have been looking up lately for the Great Lakes population of Piping Plovers. This past summer, two plover nests in Pennsylvania were the first in the state since the 1950s and the first on Lake Erie since 1977. Michigan’s Sleeping Bear Dunes National Lakeshore boasted 41 breeding pairs in 2017, trouncing a previous record of 28 pairs. And since they were listed as federally endangered in 1986, the number of plover pairs nesting along the Great Lakes coast has grown from about 17 to 76, the result of work by 爆料公社 and others to monitor the birds and protect the beaches where they breed. Despite this success, the Piping Plover rebound might be in trouble, according to a study published Tuesday in the Journal of Applied Ecology. That’s because plovers aren’t the only birds recovering in the region. Like other raptors, Merlins—a small falcon species that regularly preys on plovers and other shorebirds—have been bouncing back since the pesticide DDT was banned in...