Biology Reference
In-Depth Information
other hand, have antlers. Composed of exceedingly hard bone, they're shed each year during the winter,
and the buck grows a replacement set.
Antler development begins in early spring. The developing antlers, starting with tiny nubs, are full
of blood vessels and nerves, and have a brown covering called “velvet” because of its resemblance to
the fabric. Bucks at this stage, which lasts most of the summer, are said to be “in the velvet.”
In September or October, depending on latitude, bucks rub their antlers against saplings to remove
the velvet and polish them. The structure of these antlers is unique. When fully developed, they consist
of a curving, approximately horizontal main beam with single sharp tines projecting vertically at inter-
vals (in contrast, mule deer tines rise from the main beam and then fork). A buck's antlers, in toto, are
termed its “rack,” and the tines, including the tips of the main beams, are called “points.” Thus a buck
with four points on each side is said to have an “eight-point rack,” or is simply called an “eight-point-
er.”
The second long-standing misconception about deer is that a buck's age can be determined by its
rack. According to this theory, a buck grows spikes (two points) in its first year, four in its second year,
six in its third, and so on. While this is more or less true under some circumstances, it's wildly inaccur-
ate in others.
Although older, mature bucks do tend to have larger, heavier racks than young bucks, antler devel-
opment is largely a function of nutrition and genetics. Thus well-fed yearling bucks with the right genes
often have six or eight points in some areas, while a poorly nourished two-year-old, or one with inferior
genetics, may grow only spikes. The only accurate way to determine the age of a deer is by its teeth.
For the first two years, development and replacement of teeth are a reliable indicator. Thereafter, tooth
wear serves as a guide, although it becomes increasingly less accurate as the deer ages. In older deer,
the only truly accurate way of assessing age is by examining a tooth's annual growth layers under a
microscope.
With the advent of autumn, the breeding season or “rut” begins. Another myth, incidentally, is that
cold weather triggers the rut. Actually, biologists have learned that waning light intensity is the cause;
cold weather is simply coincidental. The rut starts in late October and peaks in November in northern
climes, but may be a month or more later in more southerly latitudes.
Then those assiduously polished antlers come into play, as bucks vie with each other for dominance.
Nonterritorial for most of the year, bucks now try to establish hegemony over a territory that may em-
brace hundreds of acres. Often dominance is established simply by minor sparring matches that quickly
convince younger, smaller bucks that discretion is the better part of valor. More evenly matched bucks,
however, may engage in genuine battles, locking antlers and attempting to shove each other around so
ferociously that the ground is torn up and shrubs trampled.
Eventually, one buck performs the whitetail equivalent of “crying uncle” and turns to flee, sometimes
being pursued and gored in the process. On very rare occasions, bucks are unable to unlock their antlers;
bound together like macabre Siamese twins, the two finally perish from starvation!
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