How Red Squirrels Are Like Tiger Moms

Megan Gannon, News Editor

Date: 19 April 2013 Time: 06:16 PM ET

Red squirrel moms know how to give their offspring an early edge in a crowded forest.

New research shows the animals can speed up the growth rate of their pups to help ensure they'll be able to compete for turf when populations are dense. Surprisingly, stress, not more food, is the key to the mother's gift, scientists say.

Bigger squirrels have a better chance of staking out an exclusive territory, where they can freely feast on the seeds hidden in spruce-tree cones. Juveniles that don't manage to acquire a territory before their first winter often do not survive.

"When population density is high, only the fastest-growing offspring survive," said study researcher Andrew McAdam, of Guelph University in Canada.

McAdam and colleagues studied North American red squirrels living in the Yukon. In field experiments, they played recordings of territorial squirrel vocalizations (known as "rattles") to trick the moms into thinking that the forests were more densely populated.

More:  http://www.livescience.com/28892-red-squirrels-stress-offspring.html