WILDLIFE -- Four conservation groups have sued the U.S. Fish and Wildlife Service for not listing the Pacific fisher, a small, weasel-family predator, as a threatened species.

The lawsuit alleges the agency failed to consider the best scientific evidence when it decided not to provide the fisher protections under the Endangered Species Act, according to the Associated Press. The lawsuit was filed Sept. 19 in federal court in San Francisco.

Fish and Wildlife had proposed listing the forest-dwelling mammal as threatened in 2014 because of concerns over logging practices, illegal pesticide use by marijuana growers and other threats.

In April, the agency determined fishers were not in danger of extinction. It said the best available science showed current threats aren’t causing significant declines in West Coast populations.

The Center for Biological Diversity, Environmental Protection Information Center, Klamath-Siskiyou Wildlands Center and Sierra Forest Legacy argue that agency’s conclusion was illegal and not support by science.

A Fish and Wildlife Agency spokeswoman declined to comment on pending litigation.