Antlers are bony structures grown and shed annually by members of the deer family (Cervidae). Unlike horns, which are permanent and have a bony core covered by a keratin sheath, antlers are true bone appendages that regrow completely each year. Their rapid development is facilitated by velvet, a soft, fuzzy skin densely packed with blood vessels and nerves to supply the necessary nutrients for growth. This yearly cycle of shedding, growth, and hardening is primarily regulated by the changing length of daylight hours, known as the photoperiod.
The Annual Antler Growth Timeline
The regeneration of a deer’s antlers typically starts in late spring, around March or April, shortly after the previous year’s hardened antlers are shed. Initial growth is slow as the pedicles, the bony structures on the skull from which the antlers emerge, begin to form the foundation. This early period requires a significant energy investment from the male deer, or buck, coinciding with the availability of lush spring forage.
The phase of rapid growth begins in late May and accelerates through June and July. During this time, the combination of increasing daylight and peak nutritional availability allows the antlers to expand at an astonishing rate. In July, when growth is at its peak, a buck can add as much as a quarter-inch to a half-inch of length per day to the main beams and tines.
Antler Development Status in August
By the time August arrives, the dynamic of antler development shifts significantly away from structural elongation and mass gain. For most northern whitetail bucks, the growth in length and overall size is largely complete by the first half of the month. The focus changes from building the framework to solidifying it for the upcoming breeding season.
The primary activity in August is the process of mineralization, where the soft, cartilaginous internal structure is transformed into dense bone. Calcium and phosphorus are heavily deposited into the porous antler matrix, making it hard and rigid. This hardening process causes the antlers to appear less swollen and bulbous compared to their look in July.
While some minor growth might continue into early August, it is a fraction of the rate seen during the peak months. This shift is crucial for ensuring the antlers are fully hardened and durable enough for the physical demands of the rut.
The Transition from Velvet to Hard Bone
The completion of the mineralization process in August sets the stage for the final transformation: the removal of the velvet. This event is triggered by the decreasing photoperiod of late summer, which signals an increase in the buck’s testosterone levels. The rise in this hormone acts as a biological switch, causing the blood vessels supplying the velvet to constrict and cut off the flow of blood.
With its blood supply severed, the velvet begins to dry out and shrink. Bucks sense this change and initiate the process of rubbing their antlers against trees, shrubs, and saplings to scrape off the dead tissue. This shedding process is often rapid, sometimes occurring completely within a 24-hour period.
The result of this transition is a hard, polished, and fully calcified antler, which is now ready for its purpose. These newly hardened bone weapons are primarily used by bucks to establish dominance hierarchies and engage in sparring matches during the autumn rut. The completion of the August hardening phase ensures the male is equipped for the physical contests necessary for mating success.