What Is a Group of Hawks Called?

Boil is the most commonly cited general term for a group of hawks, typically describing several birds gathered or rising together in flight. A more specific, behaviorally distinct term is kettle, used by birders and hawk-watchers for the large, swirling groups of migrating hawks that circle together on a single rising column of warm air, called a thermal, to gain altitude without expending energy on flapping flight. Two falconry terms round out the picture: cast, a pair of hawks released together to hunt, and leash, a group of three. Screw and stream also turn up in general collective-noun lists, though with far less documented use than boil or kettle. Mews and aerie are sometimes listed as collective nouns too, but both terms technically describe something else: a mews is the building where falconry birds were traditionally housed, and an aerie is a hawk’s nest, usually built high on a cliff ledge or in a tall tree.

Where Did the Name Come From?

Several hawk-related terms have clear roots in medieval falconry, a pastime with strict, practical vocabulary for describing how many birds were flown or housed together. Works compiling these terms, most famously the Book of Saint Albans (1486), recorded many of the collective nouns still used today, and falconry’s own precise language explains why hawks in particular ended up with terms like cast (two hawks flown together) and leash (three), alongside practical terms like mews for their housing. Boil and kettle read more like descriptive folk terms for the visual effect of a gathered or circling flock — birds rising and swirling the way bubbles rise in a pot of boiling water — though their precise origins are less thoroughly documented than the formal falconry vocabulary.

Hawk Facts

• Eyesight: Hawks have exceptionally sharp vision, estimated at several times keener than human eyesight, letting them spot small prey from great heights or distances.
• Hunting style: Most hawks hunt by soaring high overhead or watching quietly from a perch, then diving suddenly to strike prey with their sharp talons.
• Migration and thermals: Many hawk species migrate in large numbers along established flyways, riding rising thermal air columns to gain altitude efficiently — the exact behavior that gives the term “kettle” its meaning.
• Diet: Hawks are carnivores, preying on small mammals, birds, reptiles, and large insects, with diet varying by species and habitat.
• Size range: Hawks vary enormously in size, from the small sharp-shinned hawk at around a foot long to large species like the ferruginous hawk with a wingspan over four feet.
• Diversity: “Hawk” covers many species across several genera, including the broad-winged Buteo hawks and the fast, forest-hunting Accipiter hawks, found on every continent except Antarctica.

Example Sentences

• A kettle of hawks spiraled higher and higher on the thermal above the ridge as the autumn migration peaked.
• The falconer released a cast of hawks that worked the open field together, driving game between them.

Other Names for a Group of Hawks

Boil and kettle are the two terms most associated with hawks gathered or circling in flight, with kettle carrying the more precise, behavior-specific meaning among birders. Cast and leash come from falconry and refer to a specific, deliberate number of hawks flown together rather than a wild gathering of any size. Screw and stream appear in some general collective-noun references but are far less commonly used in practice. Mews and aerie are occasionally listed as collective nouns for hawks by extension, though strictly speaking one names the birds’ traditional housing and the other their nest.

Frequently Asked Questions

What is a group of hawks called?

A group of hawks is most commonly called a boil, though kettle, cast, and leash are also used depending on context.

What does a “kettle of hawks” mean?

Kettle describes a large number of hawks circling together on a rising thermal, a behavior most often seen during migration.

What is the difference between a cast and a leash of hawks?

Both are falconry terms describing a specific number of hawks flown together: a cast is two hawks, while a leash is three.

Where did the term “boil” for hawks come from?

Its exact origin isn’t precisely documented, but it likely describes the visual effect of hawks massing and circling together, similar to bubbles rising in a boiling pot.

Are hawks social birds?

Not especially. Most hawks are solitary or live in bonded pairs, though many species gather in large numbers during migration or wherever food is abundant.