ROAD TRIP!: Battles Of The Beasts
Behold The Rut As Colorado’s Male Wild Animals Gear Up For Head-Butting and Jousting Season
Story and photos by Reid Neureiter | For the GPHN
Bighorn rams crash into each other in Waterton Canyon, southwest of Denver.
The fall months of September through November and beyond mark head-banging and jousting season for many of Colorado’s horned and antlered wild animals.
Most famous perhaps is Colorado’s state mammal, the bighorn sheep. The mating season — called the “rut” — for the bighorn starts in October and continues into January. It is punctuated by the most powerful rams repeatedly bashing heads as they assert dominance and try to corner receptive ewes. The crash of heads between two large rams can sound like a gunshot.
Colorado’s moose enter their rutting season in earnest from late September to mid-October. Vic Van Ballenberghe, who studied the behavioral ecology of moose for 30 years for the U.S. Forest Service, notes that, “bull moose are well-equipped to fight. At up to 1,600 pounds they are enormously powerful. Their shoulders are huge, and during the rut, their neck muscles expand to twice their normal size. Thick forehead skin acts like armor against punctures.”
The most viewed of Colorado’s animal mating rituals are likely the elk of Rocky Mountain National Park and around Estes Park. The largest and strongest bull elk will round up a harem of cows, loudly bugling to assert dominance and attract more females. The dominant bull will chase off and sometimes clash antlers with lesser “satellite” bulls, who may try to sneak into the harem.
While actual fights are rare, bulls will engage in displays of strength to establish dominance. These intense battles are often more about posturing than actual combat. Colorado’s elk rut is at its peak from mid-September through October.
Colorado’s mule deer and white tail deer also engage in jousting of antlers to assert dominance and attract females.
Clockwise from top: Bull bison head-butt at the Rocky Mountain Arsenal National Wildlife Refuge. Young bull elk spar in Rocky Mountain National Park. White Tail deer bucks test each other at the Rocky Mountain Arsenal. Bull moose battle for supremacy in the Peru Creek drainage near Montezuma, Colo.
The bucks of the Rocky Mountain Arsenal National Wildlife Refuge, just five miles north of Park Hill, lose the velvet from their antlers in September. This allows their antlers to harden into sharp weapons, and the rut is at its peak in early November. The clash of antlers may just be for show, but bucks have been known to suffer serious injuries or even death as a result.
Several hundred American bison also call the Rocky Mountain Arsenal home. The bison rut runs from June into September, and head clashes between two big bull bison can be among the most violent conflicts in the animal kingdom — with bulls weighing as much as 2,000 pounds.
Rather than forming a harem, a male bison will form a “tending bond” with a receptive female. He warns off other males with a combination of bellows, wallowing behavior and threat displays — including head-butting and charging.
Among Colorado’s Plains residents are the pronghorn (sometimes called the “pronghorn antelope”). Pronghorn bucks will form a harem of females and warn off intruding males with dominance behavior. Rather than the high speed bashing of heads, competing male pronghorn will meet head-to-head to lock their forward-pointing horns. They use their body weight to push, shove, and twist, trying to throw the opponent off balance.
Colorado’s pronghorn rut starts in mid-September and is usually over by October. Pronghorn can be regularly seen at Aurora’s Plains Conservation Center, a refuge of 1,100 acres of short grass prairie east of Denver, on East Hampden near E-470.