Friday, December 4, 2009

Buck Fever

Antlers have been ground up and used in medicinal potions for over 2,000 years in China. And yet here in Montana, the mere sight of a deer antler causes sweaty palpitations among many males of the human species.

Visions of big antlers cause recurring, hard to cure cases of "Buck Fever" every fall and every spring.

Sun-bleached shed elk antler showing rodent chews at tips of three tines (c) John Ashley
Antlers are the only mammalian organ that can be repeatedly regenerated, and this raises the heart rates of hunters and endocrinologists alike. Antler stem cell research is currently underway. Analyzing antler formation may help us understand why regeneration is limited in other animal (ie, human) tissues.

Antlers are not horns. Horns are permanent (not shed), unbranched head ornaments that are made out of a bony core that is permanently covered with a hard, keratinized sheath that is sort of like your fingernail. Think of bighorn sheep and bison horns as very large, very intimidating fingernails. Horns usually adorn both the male and female members of the species.

(The pronghorn antelope is a notable exception to two of the horn rules. Their horns are branched, and they shed the horn sheaths each winter.)

White-tailed deer growing antlers (c) John AshleyAntlers are different. They are basically a pair of bones that are regrown and shed once each year. And except for caribou, only males grow antlers. (Normally. Females can be chemically induced to grow antlers, and this occasionally happens in the wild.) By the time the young buck is six months old, stem cells differentiate on the lining of the frontal skull bones. These cells form a "pedicle," or knob, that all future antlers will emerge from.

Antler growth is regulated by hormonal secretions, which in turn are regulated by the length of daylight ("photoperiod"). Air temperature plays no role. Lengthening daylight hours in late spring turns on the mechanism for antler growth, and in winter the decreased daylight hours causes antlers to be shed, by resorption of calcium at the pedicle.

By manipulating the amount of light that captive deer are exposed to, stem cell research has shown that deer can grow and shed new antlers as fast as every three months or, conversely, as slowly as every other year. The three-month antlers were small and unhardened when shed, and two-year antlers didn't grow any larger than normal.

Deer that died in late summer or fall, after growing but before shedding his antlers (c) John AshleyIn the wild, antlers start growing in April or early May. Early antlers are high in water and mineral content, and covered in "velvet" skin. Antlers are the fastest growing organs in the animal world, capable of extending more than three-quarters of an inch per day. They will even pull calcium from the skeletal bones if necessary. Near the end of the growth cycle, spongy bone changes to compact bone on the antler's exterior, and the velvet dies. The animal rubs the velvet off on trees and brush, and this polishes the bone-white antlers into a shiny brown.

Sighting a shiny-brown, shed antler laying in the grass is how most people get infected with Buck Fever.

Due to this irresistable antler attraction, most of the larger Wildlife Management Areas (WMA) in Montana, and other Rocky Mountain states, now restrict human access between New Years' and May 15th. This keeps the ethical "horn hunters" from disturbing the wildlife during spring. But a WMA manager once planted 77 marked antlers in a closed area, and almost half of them went missing before opening day.

Opening day (actually high noon at many WMA's) can turn into a mad dash of people on foot, on horseback, and on four-wheelers. But if you prefer, a private, 4-day 3-night "Shed Antler Hunt" in central Montana is currently advertised for only $1,700 per person, gratuity not included.

You might have to feel awfully feverish before spending that many bucks to look for a few used bones. Just walking in the woods on a regular basis would probably keep us all healthier, wealthier -- and happier.

Behind the buck (above right): Photographed with 300mm f2.8 lens on a Nikon film body, somewhere in the woods of Glacier National Park. It's good for your health to wander around aimlessly in the woods every now and then. But if you find an antler (unattached to a buck) in a national park, leave it where you found it. The rodents will chew it up for calcium, and you can leave without getting to know the park Rangers (and maybe the local judge).