The same traits that help an onlooker identify a wild creature can also help the animal send nonverbal messages such as territoriality or reproductive maturity. The intended recipient of such communication is usually another creature of the wild realm, but you too have a chance to decode the not-so-hidden memos of the wild. A skilled wildlife watcher may observe and interpret certain cues at a glance, while other signals may go undetected. From the aging inner-ring suburbs edging the City of Cleveland to the rural environs of Northeast Ohio, white-tailed deer (Odocoileus virginianus
) are easy to witness and photograph. But what to make of those bony projections--horns or antlers--adorning the heads of these massive mammals?
|This male pronghorn (Antilocapra americana) sports horns, not antlers. The female of this species also grows horns. Both will retain the head ornamentation for life. Photo captured in Fort Rock, Oregon and is available for public use via Nature Pics Online. |
Horns are made up of a two-part structure. An internal core of live bone is wrapped with a sheath made of a fibrous protein called keratin. This material is the principal component in your hair and nails! It is very strong, but can be grown into shapes accommodating the most diverse of structures. Horns are retained through the life of the animal, even if the outer sheath is shed. An example of a mammal that grows horns is the pronghorn. You will not find these antelope look-alikes in Ohio, as their native range encompasses interior western and central North America. In fact, pronghorn are endemic to this range, meaning that you cannot find them anywhere else in the world. Horns serve at least two purposes. They can be used in defense during scuffles with the same or other species. The head ornamentation can also advertise reproductive maturity with hopes to improve mating priority.
|This male white-tailed deer (buck) sports antlers, not horns. The female of this species (doe) does not grow antlers. The late-summer rack in this photo was grown in spring and shed during or just after winter. The annual cycle will continue through adulthood. |
Antlers are a single structure, not a two-part structure as I explained with horns. The whole antler is true bone. While growing, as you may often note with white-tailed deer, a hairy cover encases the bone referred to as velvet. It provides a blood source to the growing bone. After full antler growth, branches and tree trunks assist the deer in scraping off the velvet. White-tailed deer antlers serve a dual-purpose for the buck. Nonverbal communication is accomplished with a visual flash of a full-grown rack. The cue may be received by a doe, at which time an implicit handshake of reproductive maturity is understood. The second purpose for antlers is to provide males with a protective weapon in the event of a scuffle or territorial conflict with other males.
| An ephemeral layer of velvet still remains on this late-spring rack. The blood-supplying wrap will soon be scraped off using thick brush and other natural sandpaper. |
We do not have any horned mammals in Ohio, but we do have the antlered white-tailed deer. The antlers on a buck will grow back larger year after year, adding new forks or tines until the growth levels off around age 5-6. At this point, the antlers actually regrow smaller each year. The next time you see a white-tailed deer, try to identify whether it’s a male or female. Just remember, you may be looking at an antlerless male during the small window (late-winter, early-spring) when the full antlers have been shed.