Answered by Doug Halford, Ecologist and Program Manager, GSS ESER Program
Antlers are found on all members of the deer family (Cervidae) in North America including deer, elk, caribou, and moose. Caribou are the only species in which antlers are typically found on females.
Antlers are made of bone. They are NOT like fingernails. Horns (found on animals such as goats and cows) are made of keratin (like fingernails), stay on the animal’s head year-round, and continue to grow throughout the animal’s life. In contrast, antlers are made of bone, and are grown and shed each year. Deer grow their first set of antlers when they are approximately one year of age.
Antlers need nutrients, protein, energy, and hormones to grow. If any one of these ingredients is missing or not in adequate supply, the antlers will either be stunted, shed early, not go through all the stages of antler growth, or not grow at all.
Antlers originate from the periosteum, which is a tissue on the top of the deer’s skull. If you were to surgically remove this tissue and transplant it to another bone, such as a deer leg, the deer would grow an antler out of his leg. And, yes, this has been done. From this tissue comes the pedicle. This is the small part of flat bone that sticks out of the deer’s head. The deer antlers grow from the pedicle. The pedicle does not fall off with the antler.
Every year deer antlers go through a complete growing cycle, beginning with a growing time where they are “in velvet”, culminating in the large antlers, and finishing by falling off, leaving the buck’s antler-less until the next growing season. The annual antler cycle is
ultimately controlled by day length. The brain contains a kind of clock that measures the periods of light and dark and uses this information to ultimately control the growth and shedding of antlers in males.
As the antler grows the developing bone is encased in a soft membrane that looks like fur or velvet, which is why bucks at this stage are said to be “in velvet”. The velvet contains blood vessels which carry blood and nutrients to the bone, so it can grow. The velvet also contains nerve endings. Because of these nerves, bucks can feel their antlers. During this time the velvet and the underlying bone (which is mostly cartilage) is soft, so it can be injured. The ability to feel their antlers allows the bucks to get an idea of how big their antlers are and where they are in space. This is important so they don’t injure their soft, growing antlers. At this stage bucks will delicately make way through woods and will refrain from rubbing, or fighting with antlers. If they do injure their antlers, they can harden in misshapen formations or break off completely.
Continued next week: the rest of the antler growing cycle
You can’t really feel it, but your bones are continually changing. Bones are alive! They are constantly being broken down and rebuilt. Calcium gives bones their strength and helps to keep them from breaking.
Deer, elk, moose and caribou are herbivores, which means they eat plants, fruits, seeds and nuts. They obtain the calcium they need for strong bones and antler growth from the plants they eat. The calcium is absorbed by the plants from the soil.
How much calcium do you need?
Calcium-rich foods include milk, yogurt, cheese, tofu, calcium-fortified 100% orange juice, and dark leafy green vegetables like collard greens or spinach.
Calculate your calcium intake by going to the California Dairy Council’s calcium calculator. www.healthyeating.org/Healthy-Eating/Healthy-Eating-Tools/Calcium-Quiz.aspx