Hummingbirds: An Overview

What I knew then and now.

(Listen to the radio version here.)

On June 30, 1975, at Fort Custer Recreation Area not far from Kalamazoo, Michigan, on a field trip with my ornithology class, I saw my very first Ruby-throated Hummingbird—Number 74 on my life list. I’d been aware of this species since I was four years old—it had a species account and was even featured on the cover of my treasured “Little Golden Book,” Bird Stamps, that my Grandpa gave me.

The book said hummingbirds were tiny, but WHOA—it didn’t say they were as tiny as butterflies! Indeed, some of the first European explorers of the New World thought they were insects.

I don’t know where the author got the idea that the nest is often covered by a leaf, but that’s as incorrect as showing a male at the nest.

The illustration in the book shows both a male and female Ruby-throated Hummingbird at the nest, but that’s romantic fantasy—males aren’t involved in nesting at all. (Sometimes I even wonder whether male hummingbirds know where baby hummingbirds come from.) As with every species, females lay the eggs of course, but hummingbird females also take all the responsibility of choosing the nest site, building the nest, incubating the eggs, and caring for the young, both as nestlings and for 4–7 days after the chicks fledge before they grow independent.

In spring, males usually arrive a few days before females to claim and defend a territory; when the females arrive, the males display to attract them. Males with the best displays and the best territories are selected the most.

If a nest is lost, females can renest, and if their young grow independent early enough in the season, the female may start all over. That of course requires the males to stick around, always at the ready until they’re ready to migrate. Up here in Duluth, males leave in mid- or late-July. (Adult males appearing here in August are likely to be those passing through from further north.)

Besides inseminating females, males provide another useful service—they’re so territorial that they drive a lot of other nectar feeders away from the flowers. Females are larger and even more assertive than males, so those who nest near a male’s defended territory can feed quickly with little squabbling, minimizing their time away from the nest. The earlier fall migration of the males is also helpful, ensuring that more nectar will be available for the adult females and young birds until they’re ready to migrate.

This is the system for our migratory Ruby-throat. Another North America species, the Rufous Hummingbird, has one of the longest of migrations of all birds, some individuals traveling about 3,900 miles every spring and fall between Alaska and Mexico. Increasing numbers of Rufous Hummingbirds are wintering in the eastern United States, which probably helps more survive as habitat is destroyed in Mexico.

I photographed this Rufous Hummingbird in my own yard on December 1, 2021. She stuck around until December 4, flying off in the afternoon after pigging out all day.

Few tropical hummingbirds migrate at all, though they may move seasonally to different elevations depending on food availability, and many do have regular nesting seasons determined by weather and vegetation, but otherwise most elements of their nesting systems are the same, especially as far as the role of females.

This Violet-fronted Brilliant, found in the Andes, does not migrate at all. I photographed it in Ecuador in December. The species nests from January to May.

Some tropical hummingbird males are territorial, but others have “leks”—a term that can refer to the place where males gather to display to females, to the males who are gathered there, or to the behavior of gathering and displaying for females. In these species, many males may not successfully mate with a single female all season, or even for many years, while the most attractive males may mate with many females.

Many of the hummingbirds called “hermits” form leks. The White-whiskered Hermit is one species that, in Ecuador, apparently has seasonal elevational movements.

Hummingbirds are not songbirds, but taxonomists assure us that this has nothing to do with the fact that they “don’t know the words¹.” They and their relatives are morphologically different from songbirds and other species, which Linnaeus and other natural historians recognized centuries ago, and which has been confirmed by modern DNA studies.

The family includes the tiniest warm-blooded animal in the known universe, the Bee Hummingbird of Cuba, which weighs a mere 11 percent of what a Black-capped Chickadee weighs.

At the other extreme, the largest hummingbird is the Giant Hummingbird of the Andes, which weighs twice as much as a chickadee and 12 times as much as the Bee Hummingbird. I saw my lifer in December up at the Condor Lodge in Ecuador, though I saw it only briefly and didn’t get a photo.

This is not my own photo, but was taken by Arturo Nahum via Wikipedia

The hummingbird family name, Trochilidae, comes from the Greek trochilos, referring to small, swift birds, though the ancient Greeks were referring to other species such as plovers—they would have had no clue about hummingbirds, which throughout human history have been entirely limited to the Americas.

With about 375 species, the hummingbird family is the third largest of all the bird families in the world, after Tyrannidae (flycatchers—at least 430 species), and Thraupidae (tanagers—at least 390 species). Interestingly, all three of these families are limited to the Americas. Flycatchers and tanagers belong to Passeriformes, the order defined as “perching birds” (though many birds outside this family also perch). Hummingbirds belong to the order Apodiformes, which comes from the Greek apodiforme (τροχίλος), meaning “without feet.” All the birds in this order do, of course, have feet, but they’re too tiny for walking or hopping—when they must use their legs and feet for locomotion, they simply shuffle.

When the first European explorers collected and stuffed hummingbirds, they removed the feet, so many natural historians (including Linnaeus) believed they really didn’t have feet but were always airborne.

Like other birds, hummingbirds do use their legs as pistons for generating thrust when they take off, but because the legs and feet are so very tiny, they provide much less propulsion than other birds, their powerful wingbeats making up for that.

My five-year-old grandson Walter informed me a couple of weeks ago that those wings move in a figure-8, making hummingbirds the only birds who can fly backwards. He found that out on his favorite TV show, Wild Kratts. It’s thrilling to me that he’s finding more role models than just Dee Dee Nana telling him how wonderful the natural world is. When hummingbirds return this spring, he’ll be ready—he already is much more knowledgeable than I was at his age.

In flight, hummingbirds often tuck their feet under their feathers, but the feet must come out to make a landing.

1. Why do hummingbirds hum? They don’t know the words. (A time-honored joke I first read in my brother’s Boy’s Life.)