How Do Deer, Elk, and Moose Shed Their Antlers?
Did you know that deer, elk, and moose are all considered part of the “cervidae” family? If you didn’t don’t worry, like most people, you probably have no idea what a cervidae family is. Well, cervidae actually means the hoofed mammals with an even number of toes on each foot and males having antlers that naturally fall off each year. That’s right, male deer, elk, and moose spend the late spring and summer months growing antlers every year just so that it can fall off in the winter and do it all over again the following year. Crazy, right! Imagine growing something on your body and having it fall off every year. Did you also know that each year, the set of antlers being grown gets bigger than the year before until the animal reaches maturity? Once the animal has reached maturity, the antlers will eventually get smaller each year moving forward until the animal ultimately passes away.
So do the animals shed their antlers at the same time each year? Not exactly. The antler cycle hinges on endocrine and neural control, as well as the size, age and health of the animal. What that means is antlers typically hit the ground from November to April, and there’s a ton of variability both between regions and individuals. Moose are the first to drop the weight. They drop their antlers, which can weigh 40 pounds apiece, between late November and late December. Wow! 40 pounds each! Imagine carrying around 80 pounds of weight on your head! Mule deer and white-tailed deer start dropping their antlers in mid-December, but some don’t shed until early April. Elk shed last, between January and April, though the great majority lose their racks in March.
On rare occasions, bulls carry full racks up to six months later than average or don’t shed their antlers at all, usually a side effect from injury or irregular hormone levels. Injury to growing antlers encased in velvet can cause reccurring antler deformities for life. Because of this, bull elk develop an uncanny ability to thread their velvet racks through thick cover, even at a gallop. Body trauma also causes deformities. In an odd phenomenon called systematic influence, such injuries often translate to antler anomalies on the opposite side of the body.
Dr. Bronson Strickland of the Mississippi State University Extension office writes in an article that the photoperiod – the length of sunlight in a 24-hour period – and the animal's hormones drive the annual antler cycle. Changes in the amount of daylight cause the buck's hormones to generate testosterone, which activates antler growth. During the spring and summer, while antlers grow, testosterone levels go up and down.
As daylight decreases with autumn, testosterone ramps up for the breeding season, causing the antlers to stop growing. While the antlers grow they are softer, but as mating season nears, antlers harden and gain the velvet covering, which the bucks rub off on trees and saplings before mating. During the "rut,” or mating season, the antlers become hard to fight off rival males. As the rut ends, a buck's or bull's testosterone drops, and so do their antlers. They spend the rest of winter without antlers and grow new ones in the spring.
