Horns vs Antlers

We took the California grandkids on safari (at a wildlife/conservation preserve near Santa Rosa, CA) to meet some of Africa’s lesser known antelope and bird species.

On safari at Safari West, Santa Rosa, CA.  Granddaughter got tired and is sleeping on her dad in the shaded seat.

Sometimes the wildlife got really close. Note grandson’s expression.

But this wasn’t just about seeing wildlife, we learned a lot too.  For example, our guide explained the differences between horns and antlers with a demonstration.

Horns are hollow extensions of skull bone covered with a thin layer of epidermal tissue, the outer sheath of which is a keratin covering like a fingernail.  This is the skull of the an Ankole-Watusi cow, seen below.

Horns are permanent structures, they keep growing as the animal ages, and are primarily for defense (or offense in the case of combative males) and thermoregulation (getting rid of heat).  In addition, usually both sexes of members of the Bovidae (cattle, antelope, and goats) have horns.

Ankole-Watusi cattle at rest in the middle of the day under a leafless oak tree. Because of the relative lack of shade, the cattle flush blood through their horns to dissipate heat.

Ankole-Watusi cattle are native to Africa, and quite distinctive for their elongated horns that can reach up to 8 feet wide.  The interior of the horns are honeycombed with a lattice of bone that carries blood vessels to the exterior keratinized sheath which then radiates the excess heat to the environment.  So, this bone is living tissue.

This herd adopted a stray wild boar piglet that wandered into the 100 acre antelope enclosure at Safari West. He nursed from the cows (who rejected any other calf than their own) until maturity, and now seems to be a member of the herd, resting (at lower left) when they do.  

Antlers, in contrast, are almost always present only in the male of members of the Cervidae family (deer, moose, elk, and other small Asian deer species), with the exception of the caribou (or reindeer) in which females have smaller antlers than the males.  In addition, they are grown anew from buds on the skull each spring and summer and shed each winter after the rut season. They are useful as indicators of male vigor — i.e., for fighting and as sexual attractants to females, but not for thermoregulation because once the velvety covering is shed before the rut, the bone dies and lacks further vascularization.

A handsome buck ready for battle I found in my backyard in November 2012.  See post on “My trophy buck.

The largest set of antlers (by weight and tip to tip length) belonged to the extinct Irish Elk (Megalocerus giganteus — that species name says it all) that stood almost 7 feet at the shoulder and sported a 12 foot wide rack weighing about 90 pounds.  What an investment to make for just getting a female’s attention!