Where Do Hummingbirds Fit in the Order Apodiformes?

Hummingbird 101

Jun 10

If you have ever watched a hummingbird freeze in midair at a flower and then vanish in a blur, you have seen something that no other bird on Earth can quite replicate. But that extraordinary ability did not appear out of nowhere. It evolved within a very specific branch of the bird family tree, one with a name that holds a surprising clue about the birds inside it.

That branch is the order Apodiformes, and understanding it helps explain not just what hummingbirds are, but why they look, move, and function the way they do. This article breaks down the meaning of Apodiformes, introduces the three families it contains, and shows exactly where hummingbirds sit within the group.

What Does Apodiformes Mean?

The word Apodiformes comes from two ancient sources. The first part, apodo, is derived from the Greek a- (meaning "without") and pous or pod- (meaning "foot"). The second part, iformes, comes from the Latin -iformes, meaning "in the shape of" or "having the form of." Put together, Apodiformes roughly translates to "footless ones" or "those in the form of the footless."

That name was not chosen carelessly. The birds in this order share one very conspicuous trait: their legs and feet are remarkably small and limited in function. Unlike most birds that use their feet for walking, running, or scratching, the members of Apodiformes rely on their feet almost exclusively for gripping a perch. Beyond that, the feet are largely along for the ride.

In true swifts, this trait reaches an extreme. Swifts spend virtually their entire lives in the air, eating, drinking, and even sleeping on the wing. They land only to nest. Their feet, while equipped with sharp claws for clinging to vertical surfaces, cannot walk at all. In hummingbirds, the situation is similar. They can grip a branch but cannot walk or hop from one point to another. The feet are bare skin rather than scaled, which is another feature that sets Apodiformes apart from most other bird orders.

Three Families, One Order

The order Apodiformes is traditionally divided into three living families. While they differ dramatically in range, behavior, and appearance, each one carries the telltale hallmarks of the group: reduced feet, short and stout humerus bones, and elongated hand bones that anchor powerful primary flight feathers.

Apodidae — The True Swifts

Apodidae contains roughly 99 to 115 species spread across every continent except Antarctica. These are the archetypal aerial birds: sleek, fast, and almost permanently in flight. Their wings are long, narrow, and scythe-shaped, built for speed and endurance rather than hovering. The Common Swift has been recorded in sustained level flight exceeding 110 kilometers per hour, making it among the fastest birds on Earth in normal flight. Swifts nest by cementing materials together with saliva, a behavior most birders know from the edible-nest swiftlet of Southeast Asia.

The name Apodidae reflects the same Greek root as the order itself: apous, or "footless." Their hallux (hind toe) is positioned laterally and can even be reversed in some species, but the foot as a whole is incapable of true perching in the way most birds perch.

Hemiprocnidae — The Treeswifts

Hemiprocnidae is the smallest family in the order, containing just one genus and four species. All four are restricted to South and Southeast Asia, from the Indian subcontinent east to the Solomon Islands. They are commonly called treeswifts or crested swifts, the latter name referring to the small but visible crest on the forehead, a feature absent in true swifts.

The four species are:

Crested Treeswift (Hemiprocne coronata)
Grey-rumped Treeswift (Hemiprocne longipennis)
Whiskered Treeswift (Hemiprocne comata)
Moustached Treeswift (Hemiprocne mystacea)

Treeswifts sit in an interesting middle position within the order. Unlike true swifts, they are capable of perching and regularly do so on bare branches and overhead wires. Their plumage is more ornate than a typical swift, and males display striking chestnut or rufous ear patches. The face patterns of the whiskered and moustached species are particularly bold. They still catch all of their prey on the wing, but they do so by sallying out from a perch in the manner of a flycatcher rather than sweeping endlessly through the sky.

Their nests are extraordinary: tiny cup-shaped structures glued to the edge of a horizontal branch with saliva, barely large enough to hold a single egg, which is cemented to the nest surface to prevent it from rolling off.

Trochilidae — The Hummingbirds

Trochilidae is by far the largest family in the order, containing approximately 375 species across roughly 113 genera as of 2025. The family is entirely restricted to the Americas, from southeastern Alaska south to Tierra del Fuego at the tip of South America. The greatest diversity occurs in the tropical and subtropical zones of Central and South America, particularly in the Andes.

Hummingbirds occupy their own suborder within Apodiformes: Trochili. The swifts and treeswifts together form the other suborder, Apodi. This division reflects the significant anatomical differences between the two sides of the order. Hummingbirds have evolved along a radically different path from their swift relatives, developing the unique ability to hover by generating lift on both the upstroke and the downstroke of each wingbeat.

The Meaning Behind Trochilidae

The family name Trochilidae traces back to the ancient Greek word trochilos (τροχίλος), which referred to a small, quick bird. The root trochos (τροχός) means "wheel" or "that which runs in a circle," evoking the rapid, spinning motion associated with these birds. The Roman naturalist Pliny the Elder also used the term trochilus to describe a tiny bird believed to pick food from the teeth of crocodiles, likely a crocodile plover, but the name was later attached to hummingbirds by European naturalists who encountered them in the Americas. The connection to spinning or wheeling motion is fitting: a hummingbird's wings complete 10 to 80 full rotations per second depending on the species, and the bird itself can rotate, flip, and reverse direction in an instant.

What Hummingbirds Share with Swifts and Treeswifts

Despite their very different appearances and habits, the three families in Apodiformes share several physical traits that confirm their common ancestry.

All three families have:

Small, reduced feet covered in bare skin rather than scaled scutes, with limited walking ability
A short, stout humerus (the bone of the upper arm), combined with elongated hand bones, creating wings dominated by the primary flight feathers attached to the hand
Impervious nostrils without external openings that can be closed off
A single (left) carotid artery in most species, an unusual anatomical feature
Powerful flight musculature relative to body size

The short humerus is particularly important to understand. In most birds, the wing is divided fairly evenly between the arm portion (where secondaries attach) and the hand portion (where primaries attach). In Apodiformes, the hand dominates. This gives hummingbirds their extraordinary blade-like wing shape, which produces lift on both strokes. Swifts took the same basic frame in a different direction, elongating the primaries even further for speed and gliding efficiency rather than hovering.

When Did Hummingbirds Split from Swifts?

The evolutionary history of Apodiformes stretches back to the late Cretaceous period, roughly 72 million years ago, when the lineage leading to hummingbirds first diverged from the lineage leading to swifts. Swifts and treeswifts themselves did not diverge from each other until much later, approximately 34 to 42 million years ago.

Modern hummingbirds as we know them, nectarivorous, hovering, and restricted to the Americas, appear to have evolved around 22 million years ago. Intriguingly, the oldest recognized hummingbird fossils come not from the Americas but from Europe, suggesting the family may have originated in Eurasia before the lineage that produced modern hummingbirds crossed into the Western Hemisphere.

A key fossil in understanding this split is Eocypselus rowei, recovered from the Green River Formation in Wyoming and dating to roughly 50 million years ago. This small bird, less than 13 centimeters long, had a wing shape that fell between a hummingbird wing and a swift wing, offering a glimpse of the ancestral apodiform body plan before the two groups went their separate ways.

Why It Matters for Birdwatchers

Knowing that hummingbirds belong to Apodiformes gives you a meaningful context for what you are watching. The next time you see a hummingbird perched on a feeder wire, notice how it grips rather than rests. The feet grip the wire but the bird never truly relaxes its legs the way a songbird does. Notice how short and tucked the legs are. That is Apodiformes in action.

The order also reminds us that dramatic differences in appearance and behavior can exist within a single evolutionary group. A Common Swift crossing the sky at 70 miles per hour and a Ruby-throated Hummingbird hovering at a trumpet vine belong to the same order. Their shared ancestry runs deeper than their differences.

For anyone interested in taxonomy, hummingbirds represent a remarkable case study. They are the most species-rich family in their order by a wide margin, roughly 375 species compared to about 100 swifts and just 4 treeswifts. That diversification happened relatively recently and almost entirely in the Americas, where the variety of flowers, altitudes, and habitats created the conditions for an extraordinary radiation of form and color.

Frequently Asked Questions

If you still have questions about Apodiformes, how hummingbirds fit within it, or what connects them to swifts and treeswifts, the answers below cover the most common ones.

It means "footless ones." The name comes from Greek and Latin roots referring to the small, reduced feet shared by all birds in this order — hummingbirds, swifts, and treeswifts.
Yes. Hummingbirds and swifts share a common ancestor and belong to the same order, Apodiformes. Their lineages diverged approximately 42 to 72 million years ago, depending on the estimation method used. Despite looking very different today, they share key anatomical features including reduced feet, a short humerus bone, and elongated hand bones.
The three families are Apodidae (true swifts, approximately 99–115 species), Hemiprocnidae (treeswifts, 4 species), and Trochilidae (hummingbirds, approximately 375 species). Swifts and treeswifts are grouped in the suborder Apodi, while hummingbirds form their own suborder, Trochili.
Trochilidae comes from the ancient Greek word trochilos, referring to a small quick bird, with roots connecting to trochos meaning "wheel" — evoking the rapid circular wing motion of hummingbirds. The name was used by early European naturalists when they first encountered hummingbirds in the Americas.
Hummingbirds' legs and feet evolved primarily for gripping rather than locomotion. The feet are small with no functional ability to walk or hop. This is a defining characteristic of the entire order Apodiformes, all three families have reduced feet relative to most other birds.
Trochilidae is the third-most species-rich bird family in the world, after the tyrant flycatchers (Tyrannidae) and the tanagers (Thraupidae). With approximately 375 species, hummingbirds represent the vast majority of species diversity in the entire order Apodiformes.
Treeswifts are more closely related to true swifts than to hummingbirds, both belong to the suborder Apodi. However, treeswifts occupy a middle ground behaviorally: unlike true swifts, they perch regularly and have more ornate plumage, while still catching all of their insect prey on the wing.