Rufous hummingbird, Golden Gate Park, San Francisco, California

A hum-dinger of a day. National Hummingbird Day

They fly backward, dive-bomb rivals, and travel farther than most road trippers. On National Hummingbird Day, meet the rufous hummingbird—photographed in Golden Gate Park, San Francisco, California. The bird, one of nine species in the genus Selasphorus, gets its name from its rusty, reddish-orange feathers. Males flash copper backs and red throat patches that shimmer in the sun. Females are more subdued but still carry streaks of rufous on their sides and tails.

They may look sweet, but these pollinators are known for their aggressive behavior, often chasing away not just other hummingbirds, but also bees and butterflies. At around 3 inches long, this nectar-seeker is a frequent flyer in the most literal sense. Each year, it migrates from Mexico to Alaska and back—a round-trip of up to 8,000 miles. That's one of the longest migrations relative to body size in the bird world. And here's the kicker: many return to the exact same gardens and feeders year after year.

Whether you're planting flowers, or peering through binoculars as a hummer zips by, National Hummingbird Day is a good excuse to slow down and marvel at something tiny but mighty.