How do antlers benefit female caribou?
Biologists often point to antlers as a tool for females to defend the choicest grazing spots from other caribou or to ward off predators. But Miller said the role shed antlers play in supplementing a caribou’s diet is an overlooked benefit.
Migrating females collectively drop their antlers within days of giving birth. In this way, females carry their own nutritional supplement that becomes available where and when they need it most.
“These antlers last for centuries or longer and they are a source of nutrients that get revisited again and again. Given the results of our study, this is probably an important clue to a way that antlers benefit female caribou that has gone underappreciated,” he said.
Gaetano said antlers certainly could provide more than one benefit to female caribou. But female caribou are more likely to use their hooves against predators. Reindeer herders she spoke to said its go-to defense is to trample and kick.
Meanwhile, their antlers can be very small, she said, making them unlikely weapons.
“I think it’s reasonable to question how helpful they would be in fighting off a predator,” she said.
“Female caribou shed their antlers right around when they give birth,” Gaetano said. “That means they are antlerless when it would be most crucial to have antlers to defend a young calf if they were a defense mechanism.”