Squirrels and climate change

Credit: Jeffrey Lane

Jan Murie, emeritus professor of biology at the University of Alberta in Canada, is passionate about squirrels. He has even written a book: The Biology of Ground-Dwelling Squirrels. Even after retiring he keeps up with his interest. With the lead author Jeffrey Lane, a biologist at the University of Edinburgh, he has published a paper in Nature on the effect of climate change on Columbian ground squirrels. I've written about it in The Economist's Babbage blog.

Here's the blurb:

Winter is a pain in the animal kingdom. Birds can flee it by migrating to warmer climes but grounded beasts, including mammals, have no choice but to stick around. To cope, many species have learned to hibernate. Some, like the Columbian ground squirrel, spend up to nine months of each year in their alcoves. This conserves energy but leaves them with only three months to plump up for the next winter and, crucially, to procreate. To make matters worse, climate change is leading them to emerge from hibernation later than usual... read more.

While chatting with him about the paper he told me that these squirrels in captivity live up to the age of 13 years, while in the wild their average is 6 years. Adult squirrels tend to cope well, but it's the juveniles that get hunted down. Although there's nothing surprising about that, it was a reminder of what can happen when you live in the wild. Especially, if you happen to be at the bottom of the food chain.

References:

1. Lane et al., Nature, 2012, ASAP  
2. Lane et al., J. Evol. Biol., 2011, 1949

Lane JE, Kruuk LEB, Charmantier A, Murie JO, & Dobson FS (2012). Delayed phenology and reduced fitness associated with climate change in a wild hibernator Nature DOI: 10.1038/nature11335