Mule deer communication is facilitated by five integumentary glands which produce specific pheromones that elicit specific reactions.
Communication among mule deer is facilitated by the sebaceous and sudoriferous secretory cells of five integumentary glands. The cells of each gland produce specific scents, or pheromones, that elicit specific reactions in conspecifics.
The metatarsal gland produces an alarm pheromone, the tarsal gland aids in mutual recognition, the interdigital gland leaves a scent trail, and the function of the tail gland is unknown.
Urine has a pheromone function at all ages and for both sexes. It is deposited on tufts of hair surrounding the tarsal glands. In fawns, it functions as a distress signal, while in adults, it functions as a threat signal.