Giving a squirrel a personality test

It takes all kinds, even for squirrles.

http://www.sciencedaily.com/releases/2007/12/071203204150.htm

Mom's Personality Means Survival For Her Squirrel Pups
ScienceDaily (Dec. 14, 2007) — A recent study indicates that mother squirrels have personalities, and they are essential for the growth rate and survival of her pups.

Researchers at the Kluane Red Squirrel Project found that red squirrels have a range of personalities, from exploratory and aggressive to careful and passive. Both kinds of squirrels persist in the population because neither personality type offers an exclusive advantage for survival.
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In years with abundant food, McAdam said, more active squirrels use their extra energy to their advantage and the pups grow faster. When food is sparse, their high-energy lifestyle is costly and the offspring of passive squirrel mothers have the advantage.

“There is a range of personalities in squirrels because the personality that is better for fitness depends on the year,” McAdam said.

Mother squirrel personalities also affected pup survival rates. Pups from aggressive mothers had lower survival rates when they were in their mother’s nest, but it wasn’t clear if it was a result of maternal style or other environmental effects. Once they left the nest, they had better survival rates through the first winter. McAdam said it’s likely that this is because they are better at competing for territories than other pups.