Enlarge / Hummingbirds—like this golden-tailed sapphire from South America—draw the eye with their bright colors and busy, hovering flight. Biologists are drawn to understand the suite of adaptations they have evolved to survive extreme lifestyles. (credit: webguzs via Getty) 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.