The term “buck” refers to a mature male deer of species like the white-tailed deer, mule deer, and fallow deer. Classifying young male deer involves a precise system of nomenclature that reflects physical development and stage of growth. This terminology is rooted in the annual cycle of antler growth, and the specific designation changes as the young male progresses to adulthood.
Defining Terms for Young Male Deer
The earliest classification for a young deer of either sex is a fawn, typically describing the animal until it is about six months old. The first specific designation for a male is the “button buck,” describing a male fawn in its first autumn and winter. This name comes from the small, bony nubs, called pedicles, that form on the skull where antlers will eventually grow. These buttons represent the beginning of the annual antler cycle.
The next stage is the “spike buck,” usually applied to a male deer in its second year of life, or a yearling. A spike buck is defined by its first set of true, hard antlers, which are single, unbranched points without tines. While the term “spike” refers to this configuration, a male deer at this age may also develop a small, branched rack if it benefits from superior nutrition and genetics.
Age Progression and Antler Development
The transition from a button buck to a spike or branched-antlered yearling is a significant biological milestone that occurs around 18 months of age. Antler growth is a resource-intensive process, regulated by the hormone testosterone, which is itself controlled by the changing photoperiod, or the amount of daylight. The pedicles, which appeared as buttons on the fawn, begin to develop rapidly into actual bone structure in the late spring following its birth.
A young buck must divert considerable energy and nutrients, particularly protein and minerals like calcium, to support this fast-paced growth. If a buck’s diet is lacking or if it was born late in the season, its first set of hardened antlers will likely be simple spikes. Conversely, a male with excellent genetics and an abundant food supply can grow a small, branched rack with multiple points as a yearling. Antler size generally continues to increase each year, typically peaking when the buck is between five and seven years old, reflecting the allocation of resources away from body growth toward maximum antler development.
Other Deer Nomenclature
Beyond the male-specific terms, the general name for any young deer is a fawn. A young female deer is specifically referred to as a doe fawn, which is the female counterpart to the button buck.
This terminology continues to distinguish the sexes throughout maturity. An adult female is commonly called a doe, particularly for North American species such as the white-tailed deer. For species like the red deer, however, the mature female is known as a hind, and the mature male is called a stag.