Publisher Summary This chapter discusses scent marking in wolves. Scent marking in mammals—the application of an animal's odor to its environment—has long intrigued researchers from various disciplines. In canids, scent marking is a well-known phenomenon, commonly observed in domestic dogs, and there has been much speculation about its functions. Scent marking was studied during the winters of 1971–1972, 1972–1973, and 1973–1974 to help determine the role it plays in the information flow that is integral to maintaining the organization of the wolf population. Data were recorded on a detailed sketch keyed to a topographic map. Wolves scent mark in several ways that make the odors they apply to the environment especially apparent. The chapter discusses four kinds of scent marking: (1) raised-leg urination, (2) squat urination, (3) defecation, and (4) scratching.