Flehmen behavior whitetail deer buck, rutting behavior, Tennesse
Flehmen is a common behavior amongst males of certain species (often ungulates) during the rut or breeding season. The lip curling and posturing is associated with the rut. Flehmen can be defined as a mammalian behavior (as of horses or cats) in which the animal inhales with the mouth open and upper lip curled to facilitate exposure of the vomeronasal organ to a scent or pheromone.
Flehmen comes from German, in which the word applies to animals and means "to curl the upper lip." The German source of the English word is a verb, and it is used, infrequently, as such, as in "the horse flehmened." More often, the English verb form is a gerund: "the horse's flehmening." Flehmen is sometimes capitalized in English because German nouns are capitalized; however, the English word tends to be lowercase.
Whitetail deer buck, Cades Cove, Great Smoky Mountains National Park, Tennessee. Photo © copyright by Carl Donohue.