Woodpecker muscles in action

This exercise is a part of Educator Guide: Polar Bear Predation and Woodpecker Muscles / View Guide
A downy woodpecker (a tiny bird with a white belly and black back), hangs off of a small branch, presumably while hammering at it.
At just 25 grams, downy woodpeckers can exert forces of 20 to 30 times their body weight — an extreme...