Sept. 5 (UPI) -- New research proves elk antlers are used for more than just out-dueling the competition for mates. They help deter wolf attacks, too.
"Antlers are the product of sexual selection, where males are competing over breeding opportunities in a short time window in the fall," Matt Metz, a doctoral candidate at the University of Montana, said in a news release.
But where as other deer species typically shed their antlers shortly after mating season, many elk keep their antlers through the winter.
Antlers are cumbersome. For most deer, it makes sense to get rid of them as soon as possible. The sooner they're shed, the sooner a new set can grow in. Early set antlers have more time to grow bigger and stronger for the next mating season.
But as revealed by the latest study -- published this week in the journal Nature Ecology and Evolution -- shedding ones antlers comes with risk.
Metz and his research partners analyzed a decade's worth of data from the Yellowstone Wolf Project, including details on wolf-elk interactions. The data showed wolves in Yellowstone National Park preferentially hunt elk that shed their antlers early.
"We believe elk evolved to keep their antlers longer than any other North American deer because they use their antlers as an effective deterrent against wolf predation," Metz said.
The data also showed the biggest, strongest elk are most likely to shed their antlers early.
"These males that shed their antlers first are more vulnerable to being killed by wolves despite being in better nutritional condition," Metz said. "The individuals who are in the best condition are the first to drop their antlers to get a leg up on growing larger antlers for the next season and therefore gain the greatest reproductive success."
For younger, smaller bulls, already at a disadvantage during mating season, the risk of dropping their antlers early doesn't make sense.