Английская Википедия:Hawk Hill (California)

Материал из Онлайн справочника
Перейти к навигацииПерейти к поиску

Шаблон:Short description Шаблон:Infobox mountain

Hawk Hill is a Шаблон:Convert peak in the Marin Headlands, just north of the Golden Gate Bridge and across the Golden Gate strait from San Francisco, California. The hill is within the Golden Gate National Recreation Area.

It is the lookout point for the largest known flight of diurnal raptors in the Pacific states. Each autumn, from August into December, tens of thousands of hawks, kites, falcons, eagles, vultures, osprey, and harriers are funneled by the peninsular shape of Marin County into the headlands. Hawks avoid flight over water since warm thermals that provide lift are rare. Abundant populations of small mammals protected by the park are one resource that helps maintain the large number of visiting raptors in the Headlands during the fall, but the strong onshore winds hitting the hills of the Headlands provide cold updrafts and hot late summer days provide warm thermals that allow these birds to fly more efficiently.

Volunteers with the Golden Gate Raptor Observatory count and track this fall migration using bird-banding and radio-tracking techniques, all in cooperation with the National Park Service.

Raptor observations

The following table lists the annual average number of sightings by the GGRO in the Marin Headlands during autumn, for the years 2001–2009.[1]

Raptor species Sightings per year
Turkey vulture 9,179
Osprey 105
White-tailed kite 92
Mississippi kite < 1
Bald eagle 5
Northern harrier 751
Sharp-shinned hawk 4,187
Cooper's hawk 2,427
Northern goshawk 1
Red-shouldered hawk 464
Broad-winged hawk 123
Swainson's hawk 6
Red-tailed hawk 9,427
Ferruginous hawk 22
Rough-legged hawk 7
Golden eagle 20
American kestrel 542
Merlin 171
Peregrine falcon 199
Prairie falcon 8
Unidentified 1,291
TOTAL 29,028

External links

References

Шаблон:Reflist

Шаблон:Authority control