Deer are common in many natural landscapes, with male deer, known as bucks, widely recognized for their impressive antlers. These bony structures are a defining characteristic, typically associated with male animals for purposes of display and competition. While it is generally understood that only bucks grow antlers, rare instances occur where female deer, or does, also develop them, a fascinating biological anomaly.
Antler Growth in Male Deer
Antler development in male deer is a complex process primarily regulated by hormones. Antlers emerge from specialized bony protrusions on the skull called pedicels, beginning their growth in late spring. During this rapid growth, antlers are covered in soft, vascularized velvet, which supplies essential nutrients and blood flow. Testosterone levels are low during this initial growth period.
As the antlers reach their full size, typically by late summer, a surge in testosterone causes the velvet to dry and shed, leaving behind hardened bone. These fully developed antlers serve as tools for male deer to establish dominance and compete for breeding rights during the rut, or mating season. Following the breeding season, usually in winter, decreasing testosterone levels trigger the shedding of the antlers, and the cycle begins anew the following spring.
Rare Cases of Antlered Does
While antler growth is a male-dominated trait, some does can rarely develop antlers due to various biological factors. The primary reason for antlered does is often a hormonal imbalance, typically elevated testosterone levels. This hormonal shift can stem from ovarian abnormalities, adrenal tumors, or intersex conditions.
Antlers on does generally differ from those on bucks. They are smaller, thinner, and may be malformed or unbranched. These antlers also often remain perpetually covered in velvet, as the doe may not experience the testosterone increase necessary for the velvet to shed and harden. Such occurrences are extremely rare, with some studies indicating their frequency to be between 0.02% and 1.5% of deer populations. Reindeer (caribou) are a notable exception, as both male and female individuals regularly grow antlers.
Antlers Versus Horns
Antlers and horns are often confused, but these structures possess distinct biological characteristics. Antlers are made of bone and are typically shed and regrown annually. They are found exclusively on Cervidae, which includes deer, elk, and moose. Antlers usually branch and grow from pedicels on the skull.
Horns, in contrast, are permanent structures that are never shed, growing continuously. They consist of a bony core covered by a keratin sheath, the same material found in human fingernails. Horns are characteristic of Bovidae, such as cattle, sheep, goats, and many antelope species. Unlike antlers, horns generally do not branch, though their shape and size vary among species.