What role do scents play during the whitetail breeding season? How can hunters use scents to attract deer?
Most whitetail hunters know that the pheromones (scents) of deer are used as a means of communication between the sexes. Pheromones serve to stimulate a behavioral response in another animal. White-tailed deer pheromones are present in the forehead, interdigital, tarsal and metatarsal glands, while estrogen and testosterone are found in the urine. There may also be pheromones associated with the pre-orbital gland and saliva. Many of these scents are used in combination during self impregnation (rub-urination), and sign post marking (rubs, scrapes) and are interpreted by individual sexes and age classes of deer. When they are used by themselves these scents may be interpreted differently than when they are used in combination with other scents.
Recognition and Trailing Scents Tarsal scent from the gland on the inside of the rear leg is used in combination with urine as the primary recognition scent in whitetails. This scent is both sex and age specific and deer encountering tarsal scent from another deer can determine the sex and relative age of the other animal by it's scent. Tarsal is used in combination with urine during rub-urination all year long when the animal urinates over it's rear legs. All deer rub-urinate, often just after rising from their beds. Bucks rub-urinate more frequently during the rut while making scrapes.
Rub-urination is used by moose and possibly elk in response to danger, probably as an alarm signal. Deer often sniff and lick each other's tarsal area during social grooming for identification, which helps to reinforce the social hierarchy of the herd. As a result of this social grooming the deer know the smell of all the animals in their areas. I have noticed flared tarsal gland hair when bucks fight, and tarsal scent may serve as a danger or dominance signal in this instance.
The metatarsal gland on the outside of the leg is largest in mule deer, next largest in blacktails and smallest in whitetails. It's been suggested that blacktails, and possibly mule deer, use metatarsal scent when alarmed to express danger. The use of this gland is not totally understood in whitetails.
Scent from the interdigital gland (between the hooves of all four legs) is used by deer to track each other. Does and fawns use it to locate each other, bucks use it to track does. The scent of each individual deer is so specific that one animal can track one individual no matter how many others are in the area, and because scent molecules evaporate at different rates an animal can also determine which direction the other is traveling.
Forehead scent from the sudoriferous glands between the antlers is used as a recognition and dominance scent. Prior to the rut bucks take part in social grooming, sniffing and licking the forehead and tarsal area. Later, when sparring and fighting begin, dominance is established and the bucks recognize each other by scent and associate it with social level.
Bucks are able to recognize the scent of other bucks once signpost marking begins, and know which rubs and what overhanging branches at scrapes have been visited by which buck. After being threatened or attacked during the pre-rut and rut, subdominant bucks soon realize they should not be in area's near a dominant buck and its rubs and scrapes.
These recognition scents are present all year, and can be used any time during the rut by hunter, or any time of the year without fear of alarming deer. However, forehead scent is most prevalent during the rut and is more effective at that time. Because deer are curious about their home range, and often exert dominance (even does) in their core area, they may investigate any new scent to find out what deer had been in the area.
Territorial and Dominance Scents Both the signposts of rubs and scrapes are "dominance areas" of mature bucks. These signposts mark the areas used by the buck. Each rub contains scents from the forehead glands. After they rub a tree bucks often lick the rubbed tree, and because they sometimes lick their own tarsal after rub-urinating there may be urine, testosterone, tarsal and saliva left on the rub. This combination of scents is a territorial signal proclaiming dominance by mature bucks.
These same scents may occur on the overhanging branch at a scrape (urine, testosterone, tarsal and saliva, possibly pre-orbital) because the buck sniffs, licks, rubs and chews the branch with his forehead and antlers. Urine, testosterone and tarsal are deposited in the scrape during rub-urination. The buck also leaves interdigital scent on the trail of his rub-line and in the scrape as he paws the ground. This combination of scents is again a dominance and territorial signal to other bucks and a sign of a mature, dominant, breeding buck to the does.
The complex combination of scents left on signposts occurs primarily during the rut. The scents at the rub occur when bucks begin to shed their velvet. The scents at scrapes begin shortly after rubbing begins, but become most evident about a month later. These scents can be used anytime during the rubbing phase to attract bucks, but they become less effective after the first breeding phase. Because a dominant buck makes rubs and scrapes as a prelude to breeding as a proclamation of dominance, he is impelled to investigate the smell of any unknown buck intruding on his territory.
Hormones Estrogen in the urine of a doe signals sexual readiness to bucks. Bucks readily respond to estrogen, or other scents that are present when a doe is in heat, soon after they shed their velvet through the second and possibly the third estrus, which may occur as late as February. Because bucks are curious, estrogen can be used anytime of the year to attract them.
High amounts of testosterone in urine signal a buck's sexual readiness to does, and dominance to other bucks. Testosterone may attract does to a particular area, in turn attracting bucks because the does are there. In one study from the University of Georgia buck urine attracted deer better than estrous urine.
Does travel extensively when they are in heat, often traveling outside their core areas, possibly in search of healthy dominant bucks to breed with. It has been suggested that does can determine the physical health of the buck by the amount of protein in its urine. The doe chooses the buck she breeds with, possibly by the combination of the protein, testosterone and tarsal from rub-urination. I've seen does wait in the vicinity of a scrape of a dominant buck until he showed up.
Commercial Deer Scents: The Real Truth Commercial deer scents are widely used by hunters to attract deer. Scent manufacturers have responded to this demand for deer lures by providing a wide range of products in different forms; sprays, liquids, gels and solids. There are buck, buck-in-rut, doe, and doe-in-estrous urine scents; forehead, tarsal, metatarsal and interdigital scents; food; curiosity; and combination scents.
Hunters even use fox, coyote, mink, raccoon and skunk scents as either cover scents or curiosity lures. Some hunters use non-natural, or human, scents to keep deer from using escape trails. This vast array of scents can be confusing if a hunter doesn't know which scent to use or when to use it.
Urine Based Scents Using urine may not be the way to go about attracting a buck. Urine based scents are used because it is thought that bucks determine if a doe is ready to breed through the Flehmen sniff, which introduces urine to the vomeronasal organ, not to the nose. But, the vomeronasal organ accesses a part of the brain that regulates reproductive physiology, and does not elicit the immediate response needed to ensure successful breeding. In contrast, the nose accesses parts of the brain associated with immediate behavioral responses.
Sex Scents It has been suggested by several researchers that bucks detect pheromones through stimulation of the nose (rather than the vomeronasal organ), and that the stimulation of the nose is what elicits approach and copulation by the buck. Urine may not need to be present for a buck to detect an estrous doe. The buck is probably able to determine the readiness of a doe by the chemicals in vaginal secretions. If this is true, the best way to attract a buck may be by using the vaginal secretions of a doe in estrous, not urine or urine based scents.
If you are interested in more whitetail hunting tips, or more whitetail biology and behavior, click on Trinity Mountain Outdoor News and T.R.'s Hunting Tips at www.TRMichels.com. If you have questions about whitetails log on to the T.R.'s Tips message board. To find out when the rut starts, peaks and ends in your area click on Whitetail Rut Dates Chart.
This article is based on the Whitetail Addict's Manual ($19.95 + $5.00 S&H), by T.R. Michels, available in the Trinity Mountain Outdoor Products catalog.
T.R. Michels is a nationally recognized game researcher/wildlife behaviorist, outdoor writer and speaker. He is the author of the Whitetail, Elk, Duck & Goose, and Turkey Addict's Manuals. His latest products are the 2003 Revised Edition of the Whitetail Addict's Manual, the 2003 Revised Edition of the Elk Addict's Manual; and the 2003 Revised Edition of the Duck & Goose Addict's Manual.
For a catalog of books and other hunting products contact: T.R. Michels, Trinity Mountain Outdoors, PO Box 284, Wanamingo, MN 55983, USA. Phone: 507-824-3296, E-mail: TRMichels@yahoo.com, Web Site: www.TRMichels.com