The secret behind this hummingbird's dazzling color change

After 38 days of observation, a photographer has captured the secret behind one of the animal kingdom's most stunning displays: Anna's hummingbird, a North American species whose head and throat flash from deep charcoal to fiery magenta-red in an instant. This tiny illusionist has millions of microscopic grooves in its feathers that reflect light at just the right angle to create bursts of iridescence. The bird uses this signal during courtship or conflict over territory, turning sunlight into a shimmering tool for survival.