Autumn is a time when many of us turn our attention to White-tailed Deer. Man-kind has a long history of association with deer. We have depended upon its meat for food, its skin for clothing and its antlers for tools and decoration for thousands of years.
A deer’s antlers seem to hold great attraction for people. However like many things in nature that we covet, there is also a lot of confusion about antlers. For example many don’t know the difference between antlers and horns. Horns are permanent and are retained for the life of the animal. They are made of keratin with a bony core. Keratin is a protein substance without a blood supply of which hooves, hair, claws and nails are composed. Horns are found on mammals such as Bison, and Bighorned Sheep. They tend to be relatively short and thick.
The Pronghorn, sometimes called antelope, is unique to North America. It is an exception to the horn / antler rules. They have horns that have a bony core with an outer horn sheath, which is shed each year. Their horns are like a combination of horns and antlers. Both male and female Pronghorns have horns, although the males are much larger.
Antlers are completely different from horns. Antlers are made of solid bone. Only members of the deer family, Cervidae, grown antlers. Except for Caribou and Reindeer, only the male deer have antlers, with the odd exception of a rare female with a hormonal imbalance which sometimes grows a set of small antlers. Antlers are the fastest growing bones in the natural world and depending upon the species can grow as large as four to five feet long and weigh several pounds.
All antlers start from a small swelling on a male deer’s head called a pedicel or antler bud. These first appear as a tiny twist of hairs on a young male fawns head and are visible from nearly the time they are born. It is the pedicel that is the key to a large antler. For example young male deer with poor nutrition or are deficient in testosterone develop small pedicels and thus small antlers.
I think most would agree that the size of a deer’s antlers depends upon age, nutrition and inherited traits. But what is not agreed upon is to what degree each of these factors play in the eventual size of the antlers.
Antlers start to grow in early spring. The growth is triggered by the length of daylight. From the beginning the newly growing antlers are covered with a network of blood vessels and nerve endings that is known as “velvet” because it looks and feels like velvet or suede.
The rapidly growing antlers receive blood through the outer velvety skin and also through an inner core vessel. The velvet is very fragile and tender. It bruises easily and bleeds if it is damaged and even suffers frostbite if frozen. So a buck must remain careful during the growth period. This means no sparring with other bucks or running into tree branches. If an anther is seriously injured during growth it will be deformed in the place of injury. What is really amazing are the antlers will also “remember” an injury and succeeding antlers will also be deformed as long as the buck lives.
As amazing antlers are, what is more amazing is how the antler grows. Researchers have proven that a buck must borrow large amounts of calcium, the chief component of antlers, from the body. And the place where this calcium comes from is the ribs and sternum. So much calcium is taken from the ribs that they become very brittle and often break during the critical antler growing period. However the research also shows that a healthy buck takes this in stride and fractures heal smoothly and with minimal discomfort.
More on deer antlers in the next Nature Smart column. Until next time…