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February 2008

Is that a horn or an antler on that elk?

Visitors to the 3 Creek Ranch Nature Center often comment on the impressive ‘horns’ of the bull elk wandering the National Elk Refuge or around our own Ranch. They are actually referring to antlers. Horns are very different. True horns, like those found on bighorn sheep, mountain goats, bison and pronghorn, grow continuously throughout an animal’s life, and cannot be replaced if damaged or broken off. The outer surface of horns is composed of keratin, a substance similar to finger nails, and they are nourished by blood vessels within the horn itself.

Antlers, on the other hand, are renewed each year, meaning the bulls need to find a large source of calcium to supply the antler growth. With a diet of green vegetation, I hope you are asking yourself where this secret source of calcium comes from. The simple answer: from their own bones, primarily their rib cage. Since only the healthiest males will be able to afford such a large diversion of resources, an impressive set of antlers is also an impressive pedigree for parenthood.

The next time you marvel at the impressive antlers on a large elk or moose, remember, they took only 3 to 4 months to grow! They represent one of the great examples of adaptation and evolution in the deer family.