Starre Julia Vartan

I had no idea how researchers like Terrie Williams determine the metabolic rates of animals before I spoke with her for The Physiologist magazine. You put them on treadmills. Turns out it’s tricky work, but someone has to do it:

How do you get a polar bear to walk on a treadmill? That’s a very real problem Terrie Williams, PhD, and her graduate student solved in 2018. Turns out turkey baby food is the trick—and it helps that bears are one of the easier animals to train: “They are so food-motivated,” says Williams, who has studied a variety of apex predators, from circumspect wolves, to easily bored killer whales, to flighty dolphins. The toughest animals she’s worked with? African lions. “They are the only animals we have had that have torn everything apart on the treadmill—ripped off the tread, created belt problems,” she says. Because after all, “they’re cats.”