Hawks are usually solitary hunters, but under certain conditions, they gather in spectacular aerial formations called “kettles.” This behavior isn’t about social bonding; it’s a smart way to conserve energy during long-distance flights. Here’s how it works:
What is a Kettle?
A kettle is the term birders use to describe a group of hawks circling together in the sky. The name comes from the shape these formations take: like steam rising from a boiling kettle. Hawks gather this way when they find rising columns of warm air, known as thermals.
Thermals act like natural elevators, allowing birds to gain altitude without flapping their wings. By sharing these thermals, hawks can save considerable energy on migrations that span continents.
Why Do Hawks Kettle?
For most of the year, hawks hunt alone, defend territories, and only interact closely with a mate or family. But during migration, the benefits of kettling become clear:
- Energy Efficiency: Soaring in thermals requires less effort than sustained flapping.
- Navigation: Thermals often indicate favorable wind conditions for long journeys.
- Collective Advantage: Hundreds or even thousands of hawks can share a single thermal, maximizing efficiency.
Kettle vs. Flock: Why the Distinction Matters
The term “kettle” only applies when hawks are soaring together in thermals. On the ground or perched in trees, “group of hawks” is accurate enough. Unlike starlings or parrots, hawks don’t form true flocks – meaning they don’t maintain social cohesion outside these specific soaring events.
Historical Terms and Modern Usage
Older collective nouns like “cast” exist, but they’re rarely used today. The term “kettle” remains the standard among birders and scientists because it accurately describes the unique behavior of hawks in flight. Broad-winged hawks are especially known for forming massive kettles during migration, while eagles may gather temporarily for similar thermalling.
In essence, the “kettle” isn’t a social gathering; it’s a practical solution for efficient long-distance travel. Hawks return to their solitary routines once they’ve exploited the rising air currents.
