A bird—the Clark’s Nutcracker—and a tree—the whitebark pine—hold a key to the Greater Yellowstone Ecosystem. The whitebark pine relies on the Clark’s Nutcracker to spread its seed. The Clark’s Nutcracker relies on the whitebark pine for food. In ecology, this is called mutualism. Cornell researcher Taza Schaming is tracking the birds to reveal how and where whitebark pine can persist as the climate changes. Recent warm winters have created a mountain pine beetle epidemic that has killed many of the trees in the greater Yellowstone region. Taza’s study found that following a low whitebark pinecone crop, the birds did not breed—a true sign of mutualism. The data she gathers will help forest managers identify habitat where the tree and the bird might have a chance to continue their interdependence.