Everyone loves to watch hummingbirds — tiny, brightly colored blurs that dart about, hovering at flowers and pugnaciously defending their ownership of a feeder.
But to the scientists who study them, hummingbirds offer much more than an entertaining spectacle. Their small size and blazing metabolism mean they live life on a knife edge, sometimes needing to shut down their bodies almost completely just to conserve enough energy to survive the night — or to migrate thousands of miles, at times across the open ocean.
