Usually only male deer (bucks) have antlers. Once in a great while female deer (does) will also have antlers. Contrary to popular belief, antlers are live tissue, composed of bone. Antlers are the fastest growing tissue in the animal kingdom. They grow at an average of 1 to 2 inches per week during development. Antlers have a constant blood and nerve supply, which is inside the velvet antler covering, while growing. The antlers are covered in velvet from the time that the antlers start growing in the spring, until the antlers stop growing in the late summer to early fall. When the antlers stop growing, they start to shed this velvet covering. Bucks use trees and shrubs to rub their antlers on, to help rub off this velvet. This is where the term "buck rubs", comes from. Researchers agree that antlers have evolved as a weapon to gain dominance over other bucks during breeding season.
Another popular belief is that you can tell a deer's age by the number of points on each antler, this is not a good way to age a deer. The only true way to tell a deer's age is by its teeth. (See Age Determination)
- Buck 1/2 year old - It will have small bumps for antlers, these are called button bucks.
- Buck 1 1/2 years old - It will usually have one point on each antler, these are called spike bucks.
- Buck 2 1/2 years old - It will usually have 2-5 points on each side. Although the antlers can have several points they will usually still be small to medium in size.
- Buck 3 1/2 years and older - It will usually have 4-6 points on each side. This is a mature buck and will usually have medium to large antlers.
- Some bucks never develop large antlers. Antler size is influenced by genetics and diet.
During growth, the antlers have a thin layer of velvet, which is rubbed off after the antlers are fully grown. After the breeding season, bucks will shed their antlers. A new pair will then start growing in the spring.
A deer's eyes are located on the side of their head, which has advantages and disadvantages. The advantage is, deer are able to view 310 degrees around itself. This wide view allows the deer to be totally aware of the surroundings, even when it is staring straight ahead.
The disadvantage is, deer cannot focus on one location with both eyes. This causes the deer to have very poor depth perception. Deer also see at a lower resolution than humans, and are believed to be color blind.
Deer are nocturnal animals. Nocturnal means that deer can see at night, which is one of the reasons they are more active at night. Deer have more light-detecting cells in their eyes than humans, which aids their nocturnal vision. Like other nocturnal animals, their eyes shine when exposed to light at night. This is due to a reflection off a special membrane in their eye.
It is believed that deer can also see in the ultraviolet light range, which is abundant during the earlier morning and late afternoon. This ability to see better, in early morning and late afternoon, helps to explain why deer are more active during these time periods.
A deer's hearing, being far superior to that of a human, can easily detect a faint sound. It is believed that a deer's hearing is so sensitive that it can determine how far away a sound was made. A deer's hearing is one of the reasons that it is so difficult to sneak up on it without being detected. The ears of a deer are vital in helping it avoid danger. When a deer hears a sound it will instantly turn its head and point its ears in the direction of the sound. The deer will focus all of its attention on smelling, looking and listening for any more signs of danger. If the deer doesn't smell, see or hear any danger, after checking the area several times, it will usually go back to its normal routine.
Deer have a highly developed sense of smell, it is one of their best weapons for detecting approaching danger. The moist nose of a deer, similar to that of a dog, allows the deer to pick up the faintest of odors. The odor particles, drifting by on the breeze, stick to the moisture on the deer's nose and are then drawn into the olfactory organs. A deer can detect the odor of approaching danger several hundred yards away. This is why you should always try to hunt with the breeze in your face.