Kettle (birds)
Encyclopedia
A kettle is a term that birdwatchers
use to describe a group of birds wheeling and circling in the air. The kettle may be composed of several different species at the same time. Nature photographer M. Timothy O'Keefe theorizes that the word derives from the appearance of birds circling tightly in a thermal updraft
"like something boiling in a cauldron." Osprey-watcher David Gessner, however, cites a Pennsylvania lowland called the Kettle ("der Kessel" in Pennsylvania Dutch
), near Hawk Mountain
, as the source of the term.
In some species—e.g. the terns of Nantucket—kettling behavior is evidently a way of "staging" a flock in readiness for migration. Pre-migrational turkey vultures kettle by the hundreds in the thermals that rise over Vancouver Island
before they venture across the Strait of Juan de Fuca
toward Washington State. At Hawk Mountain, broadwinged hawks form kettles in September before flying south. Kettling apparently serves as a form of avian communication—an announcement of imminent departure—as well as a way of gaining altitude and conserving strength. Because of this they kettle a lot.
Birdwatching
Birdwatching or birding is the observation of birds as a recreational activity. It can be done with the naked eye, through a visual enhancement device like binoculars and telescopes, or by listening for bird sounds. Birding often involves a significant auditory component, as many bird species are...
use to describe a group of birds wheeling and circling in the air. The kettle may be composed of several different species at the same time. Nature photographer M. Timothy O'Keefe theorizes that the word derives from the appearance of birds circling tightly in a thermal updraft
Thermal
A thermal column is a column of rising air in the lower altitudes of the Earth's atmosphere. Thermals are created by the uneven heating of the Earth's surface from solar radiation, and are an example of convection. The sun warms the ground, which in turn warms the air directly above it...
"like something boiling in a cauldron." Osprey-watcher David Gessner, however, cites a Pennsylvania lowland called the Kettle ("der Kessel" in Pennsylvania Dutch
Pennsylvania German language
The Pennsylvania German language is a variety of West Central German possibly spoken by more than 250,000 people in North America...
), near Hawk Mountain
Hawk Mountain
Hawk Mountain is a mountain ridge, part of the Blue Mountain Ridge in the Appalachian Mountain chain, located in central-eastern Pennsylvania near Reading and Allentown. The area includes 13,000 acres of protected private and public land, including the 2,600 acre Hawk Mountain Sanctuary.The River...
, as the source of the term.
In some species—e.g. the terns of Nantucket—kettling behavior is evidently a way of "staging" a flock in readiness for migration. Pre-migrational turkey vultures kettle by the hundreds in the thermals that rise over Vancouver Island
Vancouver Island
Vancouver Island is a large island in British Columbia, Canada. It is one of several North American locations named after George Vancouver, the British Royal Navy officer who explored the Pacific Northwest coast of North America between 1791 and 1794...
before they venture across the Strait of Juan de Fuca
Strait of Juan de Fuca
The Strait of Juan de Fuca is a large body of water about long that is the Salish Sea outlet to the Pacific Ocean...
toward Washington State. At Hawk Mountain, broadwinged hawks form kettles in September before flying south. Kettling apparently serves as a form of avian communication—an announcement of imminent departure—as well as a way of gaining altitude and conserving strength. Because of this they kettle a lot.