Hawk Hill is a 920 feet (280 m) peak in the Marin Headlands

Marin Headlands

The Marin Headlands is a hilly area at the southernmost end of Marin County, California, just north of the Golden Gate Bridge. The Headlands are located just north of San Francisco, immediately across the Golden Gate Bridge. The entire area is part of the Golden Gate National Recreation Area...

, just north of the Golden Gate Bridge

Golden Gate Bridge

The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the opening of the San Francisco Bay into the Pacific Ocean. As part of both U.S. Route 101 and California State Route 1, the structure links the city of San Francisco, on the northern tip of the San Francisco Peninsula, to...

 and across the Golden Gate

Golden Gate

The Golden Gate is the North American strait connecting San Francisco Bay to the Pacific Ocean. Since 1937 it has been spanned by the Golden Gate Bridge...

 strait from San Francisco, California

San Francisco, California

San Francisco , officially the City and County of San Francisco, is the financial, cultural, and transportation center of the San Francisco Bay Area, a region of 7.15 million people which includes San Jose and Oakland...

. The hill is within the Golden Gate National Recreation Area

Golden Gate National Recreation Area

The Golden Gate National Recreation Area is a U.S. National Recreation Area administered by the National Park Service that surrounds the San Francisco Bay area. It is one of the most visited units of the National Park system in the United States, with over 13 million visitors a year...

.

It is the lookout point for the largest known flight of diurnal raptors

Bird of prey

Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....

 in the Pacific states. Each autumn, from August into December, tens of thousands of hawk

Hawk

The term hawk can be used in several ways:* In strict usage in Australia and Africa, to mean any of the species in the subfamily Accipitrinae, which comprises the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter genus includes goshawks,...

s, kites

White-tailed Kite

The White-tailed Kite is an elanid kite of genus Elanus found in western North America and parts of South America.Their coloration is gull-like, but their shape and flight falcon-like, with a rounded tail...

, falcon

Falcon

A falcon is any species of raptor in the genus Falco. The genus contains 37 species, widely distributed throughout Europe, Asia, and North America....

s, eagle

Eagle

Eagles are members of the bird family Accipitridae, and belong to several genera which are not necessarily closely related to each other. Most of the more than 60 species occur in Eurasia and Africa. Outside this area, just two species can be found in the United States and Canada, nine more in...

s, vultures

Turkey Vulture

The Turkey Vulture is a bird found throughout most of the Americas. It is also known in some North American regions as the Turkey Buzzard , and in some areas of the Caribbean as the John Crow or Carrion Crow...

, osprey

Osprey

The Osprey , sometimes known as the sea hawk or fish eagle, is a diurnal, fish-eating bird of prey. It is a large raptor, reaching more than in length and across the wings...

, 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

Golden Gate Raptor Observatory

The Golden Gate Raptor Observatory is a non-profit organization whose mission is to study migrating birds of prey along the Pacific coast and to inspire the preservation of raptor populations in California...

 count and track this fall migration using bird-banding

Bird ringing

Bird ringing or bird banding is a technique used in the study of wild birds, by attaching a small, individually numbered, metal or plastic tag to their legs or wings, so that various aspects of the bird's life can be studied by the ability to re-find the same individual later...

 and radio-tracking techniques, all in cooperation with the National Park Service

National Park Service

The National Park Service is the U.S. federal agency that manages all national parks, many national monuments, and other conservation and historical properties with various title designations...

.

Raptor observations

The following table lists the annual average number of sightings by the GGRO in the Marin Headlands during autumn, for the years 1998-2007.

Raptor species	Sightings per year
Turkey Vulture Turkey Vulture The Turkey Vulture is a bird found throughout most of the Americas. It is also known in some North American regions as the Turkey Buzzard , and in some areas of the Caribbean as the John Crow or Carrion Crow...	9,406
Osprey Osprey The Osprey , sometimes known as the sea hawk or fish eagle, is a diurnal, fish-eating bird of prey. It is a large raptor, reaching more than in length and across the wings...	107
White-tailed Kite White-tailed Kite The White-tailed Kite is an elanid kite of genus Elanus found in western North America and parts of South America.Their coloration is gull-like, but their shape and flight falcon-like, with a rounded tail...	84
Mississippi Kite Mississippi Kite The Mississippi Kite is a small bird of prey in the family Accipitridae. It is 12 to 15 inches beak to tail and has a wingspan averaging 3 feet . Weight is from 214 to 388 grams . Adults are gray with darker gray on their tail feathers and outer wings and lighter gray on their heads...	< 1
Bald Eagle Bald Eagle The Bald Eagle is a bird of prey found in North America. It is the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle...	4
Northern Harrier	818
Sharp-shinned Hawk Sharp-shinned Hawk The Sharp-shinned Hawk is a small hawk. In fact, "sharp-shins" or "sharpies" are the smallest to reside in USA and Canada, though some Neotropical species are smaller...	4,634
Cooper's Hawk Cooper's Hawk Cooper's Hawk is a medium-sized hawk native to the North American continent and found from Canada to Mexico. As in many birds of prey, the male is smaller than the female...	2,619
Northern Goshawk	1
Red-shouldered Hawk Red-shouldered Hawk The Red-shouldered Hawk is a medium-sized hawk. Its breeding range spans eastern North America and along the coast of California and northern to northeastern-central Mexico.-Description:...	412
Broad-winged Hawk Broad-winged Hawk The Broad-winged Hawk is a small hawk of the genus Buteo. During the summer some subspecies are distributed over eastern North America, as far west as British Columbia and Texas; they then migrate south to winter in the neotropics from Mexico down to southern Brazil. Other subspecies are all-year...	126
Swainson's Hawk Swainson's Hawk The Swainson's Hawk , is a large buteo hawk of the Falconiformes, sometimes separated in the Accipitriformes like its relatives. This species was named after William Swainson, a British naturalist...	6
Red-tailed Hawk Red-tailed Hawk The Red-tailed Hawk is a bird of prey, one of three species colloquially known in the United States as the "chickenhawk," though it rarely preys on standard sized chickens. It breeds throughout most of North America, from western Alaska and northern Canada to as far south as Panama and the West...	9,891
Ferruginous Hawk Ferruginous Hawk The Ferruginous Hawk , Buteo regalis , is a large bird of prey. It is not a true hawk like sparrowhawks or goshawks, but rather belongs to the broad-winged buteo hawks, known as "buzzards" in Europe...	24
Rough-legged Hawk	9
Golden Eagle Golden Eagle The Golden Eagle is one of the best known birds of prey in the Northern Hemisphere. Like all eagles, it belongs to the family Accipitridae. Once widespread across the Holarctic, it has disappeared from many of the more heavily populated areas...	21
American Kestrel American Kestrel The American Kestrel , sometimes colloquially known as the Sparrow Hawk, is a small falcon, and the only kestrel found in the Americas. It is the most common falcon in North America, and is found in a wide variety of habitats. At long, it is also the smallest falcon in North America...	595
Merlin Merlin Merlin is a legendary figure best known as the wizard featured in the Arthurian legend. The standard depiction of the character first appears in Geoffrey of Monmouth's Historia Regum Britanniae, written c. 1136, and is based on an amalgamation of previous historical and legendary figures...	177
Peregrine Falcon Peregrine Falcon The Peregrine Falcon , also known as the Peregrine, and historically as the Duck Hawk in North America, is a widespread bird of prey in the family Falconidae. A large, crow-sized falcon, it has a blue-gray back, barred white underparts, and a black head and "moustache"...	172
Prairie Falcon Prairie Falcon The Prairie Falcon is a medium-sized falcon of western North America.It is about the size of a Peregrine Falcon or a crow, with an average length of 40 cm , wingspan of 1 metre , and weight of 720 g...	5
Unidentified	1,534
TOTAL	30,652