There are two distinct law enforcement programs and three types of officers in the U.S. Fish and Wildlife Service.
The Division of Refuge Law Enforcement has federal wildlife officers.
The Services Office of Law Enforcement has special agents and wildlife inspectors.
Federal wildlife officers and special agents have similar authority to carry firearms, make arrests and enforce conservation laws, but officers work primarily on refuges and agents work primarily off refuges.
Wildlife inspectors are importexport control officers who ensure that wildlife shipments comply with U.S. and international wildlife protection laws. They refer violations to special agents.