My girlfriend and I feed squirrels who live in our apartment complex. The squirrels recognize us on sight and know our voices.

Several times last winter I noticed two squirrels who had a nest somewhere near the roof of the building opposite our apartment. When they saw or heard us they ran along the roof, hopped to a tree, climbed down, and ran over to get some nuts from us. Most of the time we have unshelled peanuts, sometimes unshelled walnuts or pecans.

Today, I started to wonder about the squirrel efficiency of this process. They have to run about 25 yards (approx 25 meters), climb down about 10 yards/meters, get a few nuts and retrace their steps to get back to the nest.

What is the energy break even point here? When the temperature is about 25 F (- 4C), how much energy do they expend getting to us and getting home and maintaining body temperature? How much energy do they get from a peanut?

Does anybody study this kind of problem? Does anybody have an estimate for squirrel steps per peanut?