Samplings: November 2009

Ghost of Predation Past

Colorado marmots “remember” a long-gone foe.

Yellow-bellied marmot

Tina Wey

Talk about bearing a grudge! Even though wolves were extirpated from Colorado in the 1930s, yellow-bellied marmots there still fear them, a recent study shows.

Foxes, coyotes, and mountain lions all think marmots make a nice meal. But each predator represents a different threat: foxes, for example, usually attack pups, whereas coyotes are adept at catching marmots of all ages. Belying their name, adult yellow-bellies sometimes actually chase foxes, but they turn tail and scamper to their burrows when a coyote shows up. The rodents react appropriately to the danger level.

Daniel T. Blumstein, a behavioral ecologist at the University of California, Los Angeles, and two colleagues were curious to see if the Colorado marmots would still respond defensively to wolves—a major menace way back when. They sprinkled horse feed in a field to attract marmots, and erected life-size photographs of a fox, coyote, mountain lion, wolf, or African antelope (as a control) nearby. When the researchers suddenly unveiled one of the pictures, foraging marmots were most likely to flee in response to the wolf.

Blumstein says the marmots’ reaction supports the “multipredator hypothesis,” the notion that prey maintain their fear of extinct predators so long as similar enemies—probably coyotes, in the marmots’ case—remain in play to keep them on their toes. (Animal Behaviour)