A deer with velvet-covered antlers stands in a field in Sharon Woods Metro Park, Westerville, Ohio.
Deer have antlers.
That’s a fact of life you learn very early, thanks to Rudolph and the rest of Santa’s crew. It fits in with other facts learned early, like the sky is blue and ice cream tastes much better than Brussels sprouts. You don’t question it. You accept it and move on.
I never gave much thought to antlers because it's something that has no impact on my daily life. But as I was preparing this photo, captured on a summer morning in a park north of Columbus, Ohio, to post as my photo of the week I realized how odd it was that male deer (and females, in rare cases — about one out of every 20,000) grow large coat racks on top of their heads each year.
Why does that happen? And how?
According to various online sources, antlers are bony structures that grow from pedicles on a deer’s head beginning in late April or early May and continue growing through late August or early September. Deer antlers are primarily grown for mating purposes and to battle other male deer for the choice of mates.
But the antlers are also an indicator of health. The larger the rack, the healthier the buck.
Growing antlers takes nutrients away from the rest of the body. Deer antlers can grow a quarter of an inch or more a day, making them one of the fastest growing tissues among all animals. Mineral requirements for antler growth can be as much as three times greater than a deer’s normal mineral requirements for skeletal growth and maintenance. That stresses a deer’s body.
A deer’s diet provides much of the calcium and phosphorus necessary for antler mineralization and growth, but the remainder comes from resorption (stealing minerals from the deer’s skeleton). Healthier, stronger bucks — those able to supply (or withstand the loss of) nutrients required for antler growth — grow larger racks with more points.
The photo shows the deer’s antlers wrapped in a soft material called velvet. The velvet is a type of skin filled with veins and arteries that feed nutrients to the antlers as they grow.
During the summer months, increased levels of testosterone slow antler growth. Blood vessels feeding the velvet constrict, cutting off the blood supply to the antlers. The velvet dries and sheds by late August or early September, revealing the antler's bony structure in time for autumn mating season. The antlers, which no longer have a source of nutrients, fall off over the winter. Then the process begins again in the spring.
That’s what I learned through my online research. The various online sources were heavy on the “how” information and discussed the purpose that antlers play, but I found little on why deer grow antlers. Or why other species — dogs, cats, bears, for instance — don’t. I guess it’s just one of those facts of life I need to accept and move on.
Mineral requirements for antler growth can be as much as three times greater than a deer’s mineral requirements for skeletal growth and maintenance.