10 Fun Facts About the Ruby-throated Hummingbird
Meet the spirited sprites whose feats are as dazzling as their feathers
“Hummingbirds hardly need a description,” the renowned bird illustrator and naturalist Roger Tory Peterson once wrote of the Ruby-throated Hummingbird. Yet we can’t resist describing them anyway. The diverse hummingbird family—363 species exclusively found across the Americas—charms us with charisma that few birds can match, and the dazzling Ruby-throated is no exception. An enthusiastic patron of backyard feeders and woodland wildflowers alike, Ruby-throated Hummingbirds enchant admirers with their shimmering green plumage and the male’s brilliant red throat feathers, called a gorget.
Although 24 hummingbird species have been recorded in the United States, the Ruby-throated is the only one that breeds east of the Mississippi River, with its range extending throughout the Midwest as far as Texas and encompassing much of southern Canada. During the non-breeding months, Ruby-throats join many other hummingbird species in Central America. Check out these 10 fun facts below to learn more about these small but mighty birds, and when you’re done, track their migration yourself with Audubon’s Bird Migration Explorer.
1.) A hovering Ruby-throated Hummingbird beats its wings around 50 times a second. Hummingbirds are the only bird family capable of hovering for extended periods of time. Their specially adapted wings rotate from the shoulder in a horizontal figure-eight motion to generate lift while remaining stationary in the air. A hummingbird’s unique flight style allows it to fly forward, backward, and even upside down with great agility.
2.) Ruby-throats only weigh about as much as a penny. Males average 3 grams, while females are about 3.5 grams, or around one-tenth of an ounce. As tiny as they are, though, Ruby-throated Hummingbirds are middleweights by hummer standards. The Bee Hummingbird, the world’s smallest bird, weighs less than a dime at around 2 grams, and the world’s largest hummingbird, the Giant Hummingbird, weighs up to a (relatively) whopping 24 grams—about as much as one AA battery.
3.) Despite their diminutive size, Ruby-throated Hummingbirds are endurance champions. In the fall, some will migrate from southeastern Canada as far south as Costa Rica, with the most intrepid birds crossing the Gulf of Mexico in one nonstop, 500-mile flight. To prepare for such an arduous journey, the birds double their body mass, building up fat reserves with energy-dense flower nectar and insects. Along the way, they use favorable winds to travel up to 300 miles on a single gram of fat.
4.) Hummingbirds run on flower power, and Ruby-throats are particularly reliant on jewelweed, a native plant that has orange flowers and is widespread across the bird’s range. While many flowers offer nectar to attract pollinators and increase their reproductive success, Ruby-throats and jewelweed have a more involved symbiotic relationship: The jewelweed’s late blooming time coincides with the bird’s early fall migration south, providing valuable energy along their journey; meanwhile, research shows that the plant seems to have evolved a more curved nectar spur, which increases pollen transfer.
A Ruby-throat’s heart races as fast as 20 beats a second, and its resting body temperature sits at about 102 Fahrenheit.
5.) When Ruby-throated Hummingbirds arrive to their breeding grounds in early spring before most plants have bloomed, they tap a surprising food source: the sap in Yellow-bellied Sapsucker holes. In fact, Ruby-throats will build their nests near sapsucker wells to take advantage of the steady and dependable food supply. The birds also feed on insects attracted to the sugary liquid.
6.) Hummingbirds boast the highest metabolic rate by weight of any vertebrate: A Ruby-throat’s heart races as fast as 20 beats a second, and its resting body temperature sits at about 102 Fahrenheit. It takes a lot of energy to maintain such an intense pace, which is why a Ruby-throat can consume up to three times their body weight in food in a day.
7.) Ruby-throats may burn a lot of energy, but they also have a clever adaptation for saving it. When the birds need to conserve their valuable fat stores—like during a cold snap common across its eastern range or a migratory rest stop—they enter a kind of short-term hibernation called torpor, dramatically lowering their body temperature and heart rate to preserve vital energy.
8.) Female Ruby-throats are talented nest builders. Males don't stick around for nest making or raising the chicks, so the female picks a shaded branch and constructs a tiny cup, just big enough for her to squeeze into, out of plant matter woven together with spiderwebs that she collects by sticking them to her beak and breast. She applies lichen to the exterior for camouflage and lines the interior with down from plants like thistle and dandelion to cushion the tiny eggs—about the size of Roosevelt’s head on a U.S. dime.
9.) Male Ruby-throated Hummingbirds are intensely territorial during breeding season, chirping angrily at other males who come too close and chasing off any and all intruders or threats—including much larger birds like raptors. A rival hummingbird who refuses to flee is subjected to bill jabs and kicks from tiny claws. Hummers are also notoriously hostile around feeders and gardens, where aggressive males and females alike strive to defend their food sources.
10.) Along with their daring dogfights, male hummingbirds show off their aerial acrobatics with a complex courtship display. When trying to woo a potential mate, a male will first catch her eye by flashing his iridescent red gorget. Once he’s got her attention, he swoops down from as high as 50 feet in the air before looping back up to repeat the U-shaped display. This leads into a close-up performance of quick side-to-side flights. The female tracks her suitor closely, and if she’s impressed, she’ll respond with a “mew” call and indicate her receptiveness to mate.