An autumn walk in whitetail country often reveals trees with sections of bark ripped and peeled away. These scars, inflicted by a white-tailed buck rubbing its antlers on the trunk, are called “buck rubs.” This rubbing behavior might seem odd, but science explains why bucks do it.
Buck rubs sometimes appear in early to mid-September. That’s typically when bucks lose their antler velvet, a soft, blood-rich tissue that covers growing antlers from late spring through summer. Throughout this growing period, the buck’s rack is fairly soft and flexible, but it hardens to bone by late summer as the bucks’ testosterone levels start climbing. Once antlers are fully developed, their velvet starts drying and shedding. Bucks accelerate its removal by rubbing their antlers on trees or raking them through brush. They usually shed all their velvet in less than 24 hours.
Early-season rubs typically aren’t as aggressive, destructive and common as those made weeks later when the bucks’ testosterone levels start peaking as the breeding season, or rut, nears. For most of the country, the rut occurs from late October to early December. Before and during the rut, bucks rub trees to mark their territory, work off aggression, and intimidate other bucks. A series of rubs made along a trail or field edge are called rub lines, and provide clues about a buck’s travel patterns.
Buck rubs also serve as dominance symbols and communication signposts. They notify other deer of the buck’s presence and possibly its breeding intentions. When a buck rubs trees, brush and saplings, it leaves behind scents from its forehead. Other deer often sniff rubs, and sometimes rub the spot themselves before moving on. Even does sometimes rub their foreheads on a prominent rub to signal their presence.
Bucks rub trees as small as your pinky finger and as large as a telephone pole, sometimes even bigger! Deer hunters often debate whether a buck’s antlers and body size correlate to the diameter of trees it rubs. However, researchers and hunters regularly report big bucks rubbing saplings and small bucks rubbing large trees. In general, though, truly giant rubs on trees 10 inches or more in diameter are initiated by mature, large-antlered bucks.
For those reasons and others, buck rubs are truly fascinating. Elements of mystery surround them, sparking the bowhunter’s imagination and igniting high expectations for archery season.