By Chris Cook, Wildlife Biologist
All wildlife species communicate with other animals of the same species. Communication is important for breeding, feeding, and many other things necessary for an animal’s survival. Some animals communicate using scent, some use sound, and others use body movement and posturing. White-tailed deer communicate using all three.
Scent communication is probably the most important method of communication in the white-tailed deer’s world. Scent communication is an important part of the breeding process, as well as the establishment of the social hierarchy within a deer herd.
Scent in white-tailed deer comes from one of seven glands. Three of these glands are located on the legs. The interdigital glands are between the hooves of all four feet. The metatarsal glands are on the outside of the hind legs and the tarsal glands are on the inside of the hind legs.
The tarsal gland is perhaps the most important of the glands found on the leg. This gland consists of a patch of elongated hairs underlain by an area of large sebaceous glands. The sebaceous glands secrete a fatty lipid that adheres to the hairs of the tarsal gland. This area gives off a strong, musky odor. This odor is the result of urine being deposited on these glands and mixed with lipids during a behavior known as rub-urination. During rub-urination, a deer rubs the two tarsal glands together while urinating over them. All deer engage in this rub-urination behavior throughout the year; however, this process is much more frequent during the breeding season-particularly among males. Deer use this gland to recognize other individuals in the herd and to give information relative to their sex, social status, and reproductive condition.
Other glands include the preorbital glands located in small pockets in the corners of the eyes; the forehead gland located on the entire area between the antlers and eyes; the nasal gland located inside the nose; and the preputial gland located in the penile sheath. The function and importance of several of these glands are unknown at this time.
Deer also use audible calls to communicate with each other. Several different vocalizations have been analyzed and identified as uniquely specific calls. The snort is probably the most recognized of these calls. Deer usually make this shrill whistling/blowing sound when alarmed and often stomp a front hoof. Most hunters probably have heard this call at one time or another. Deer emit a high-pitched bawl in situations of extreme distress. The bawl is a high-pitched, intense call often given by injured or traumatized deer.
Several calls are issued between does and their fawns. A low maternal grunt call is given by a doe to communicate with her fawn, and a series of mews, bleats, and whines are issued from fawns attempting to suckle their mothers or communicate some form of distress.
In addition to scent and vocal communication, deer use body language and posturing to communicate. Most body language occurs with the context of the social position an individual deer occupies in the herd. Subordinate members of the herd, both male and female, generally avoid physical contact with dominant members. Direct eye contact also is avoided. Dominant animals may use various postures to signal their intentions. A common posture is a direct stare coupled with dropping the ears back along the neck. When a dominant animal makes this posture, the subordinate usually will retreat from the area or refrain from the behavior that elicited this signal.
Researchers have categorized body language into two postures. These are “high head” postures and “low head” postures. High head postures indicate willingness to rear and flail at another deer, while a low head posture indicates willingness to confront and chase. Among does, when two deer of the same social standing fail to back down in the face of threat postures, both may rear and flail at each other violently. Does also use the rearing and flailing behavior to drive away yearlings during the breeding season and fawning period.
Among bucks, two males of equal status confronting one another may face off with heads lowered and ears pinned back. The hair along their backs usually is bristled as well. Often these males walk stiff-legged toward one another or circle several times. If the confrontation escalates, the hardened antlers often are used to charge and attack each other. These incidents may involve some light shoving, and on rare occasion may result in a violent or lethal fight. Outside the breeding season, it is common for one buck to decline serious combat and accept the role of subordinate. Bucks also will rear and flail at one another during confrontations, especially when their antlers are still in velvet.