Federal wildlife managers are gearing up to remove gray wolvesfrom the Endangered Species List. But some environmentalists say the species isn’t ready and that the government is basing its decision on outdated science. A group of biologists in four western national parks are looking at the impacts of wolf deaths on their packs and how this could affect the greater population.

Congress has taken a piecemeal approach to delisting gray wolves, removing federal protections one population area at a time. Gray wolves in Montana, Idaho, eastern Washington and Oregon, and northern Utah were deemed “recovered” in 2011…