Uncommon and often local winter migrant to coastal bays and inshore waters. Singles rarely occur on reservoirs and larger lakes. Breeds on lakes in remote northern moorlands and taiga. Smaller and sleeker than Common Loon (Great Northern Diver). Larger and darker than Red-throated Loon, with straight, daggerlike bill. All plumages have white "hip patch" usually visible on swimming birds. Breeding plumage distinctive, with pale gray head and hindneck, white-checkered back. Nonbreeding plumage has an even border between gray and white on neck (jagged on Common), and gray hindneck paler than back.