Scientists Recommend Vole Shaving

Sometimes scientists need to make their research subjects' lives harder. No matter how much affection they may feel for those flatworms or fish or pigeons, there are certain things they can only learn by forcing the animals to use more energy. But for animals living in the wild, this can be tricky. Now scientists studying rodents in Eastern Europe say they've found a convenient way to do it: just give the animals a quick shave. Paulina Szafrańska, at the Mammal Research Institute of the Polish Academy of Sciences, is interested in energy budgets. The energy animals get from food, she says, is like money to be spent on their daily activities: scurrying around, hunting, keeping their bodies warm, and so on. "When we make a hole in the budget" by increasing the cost of one of those activities, she says, the animal has to cut back somewhere else. "We call ...