Hummingbirds may look delicate, but the males are fiercely territorial. A reliable patch of flowers is a feeding station worth defending, and any rival that drifts too close is met with a high-speed chase through the canopy.
Hummingbirds are the smallest birds in the world. The bee hummingbird of Cuba weighs less than two grams, yet its wings beat 50 to 80 times per second, letting it hover in place, fly backwards, and even briefly upside down. That agility burns fuel fast. A hummingbird's heart can race past 1,200 beats per minute in flight, so the bird must visit hundreds of flowers a day to keep up, and many species drop into a low-metabolism state called torpor overnight to survive until dawn.