California is the third largest large state of the United States, situated on the west coast. The state has an enormous number of birds, with over 700 species – the largest bird count of any state. The fantastic bird diversity is due to its large size and wide variety of habitats, including desert, beach, marshland, arid scrub, redwood forest, grassland, and many more.
Amongst the massive number of bird species are many diurnal birds of prey, including the falcons, a group of raptors belonging to the Falconidae family. Falcons are known for their incredible speed and hunting capabilities.
For example, the Peregrine Falcon (Falco peregrinus) is the fastest animal in the world when diving – reaching speeds of almost 240 miles per hour (386 kilometres per hour).
Seven species belonging to the Falconidae family have been seen in California, but only four of the true falcons (in the genus Falco) are seen regularly. The remaining Falco species are the vagrant Gyrfalcon (Falco rusticolus) and the Eurasian Kestrel (Falco tinnunculus), having been seen once in Marin County.
The Gyrfalcon breeds in the arctic region and very rarely moves as far south as California, so there are only around ten records of this species in the state. The Eurasian Kestrel is even rarer in the state – having been seen once.
The family also includes the Crested Caracara (Caracara plancus), which occurs in California but belongs to a different subfamily, has a very different body shape and behaves very differently to the true falcons.
California’s birding sites are widespread and diverse, but each contains its own unique parts. When looking for falcons in California, most of the top birding destinations have the four species. Without further ado, here are some of the most notable birding locations in the Golden State.
They are Point Reyes National Seashore, Klamath Basin National Wildlife Refuges Complex, Arcata Marsh and Wildlife Sanctuary, Elkhorn Slough National Estuarine Research Reserve, Golden Gate National Recreation Area, Yosemite National Park, San Gabriel Mountains, Bolsa Chica Ecological Reserve, Cabrillo National Monument, Andrew Molera State Park and Morro Bay.
In the following text, we will describe the four non-vagrant Falco species in more detail.
4 Falcons That You Can See In California
1. Peregrine Falcon
- Scientific name – Falco peregrinus
- Lifespan – 13 years (average), 19 years (maximum recorded)
- Size – 14.2 to 19.3 in (36 to 49 cm)
- Weight – 18.7 to 56.4 oz (530 to 1600 g)
- Wingspan – 39.4 to 43.3 in (100 to 110 cm)
- Status – Least concern
The Peregrine Falcon is a medium raptor with long, pointed wings and a long tail. They have blue-grey upper parts, grey on back (adults) or brown on back (juveniles), a dark head, a thick moustache, a whitish underside, and a horizontally barred breast.
The underwing is whitish with black checkered markings. This falcon produces a loud kak-kak-kak call.
Peregrine Falcons breed in open areas with tall buildings or cliffs that they use as nest sites. The nest is usually placed on a ledge. They may also breed on towers, silos, skyscrapers, and bridges. In some areas, Peregrine Falcons utilise abandoned nests made by corvids, cormorants or other birds of prey.
The female lays two to five eggs per clutch, and only one clutch is laid per season. The eggs are pale cream or brownish with brown, purple or red blotches or dots. The eggs are incubated for 29 to 32 days. After hatching, the chicks remain in the nest for 35 to 42 days before they begin to fledge.
Peregrine Falcons feed mainly on birds and have been documented to prey on over 450 species of birds in North America. Worldwide, they have been recorded feeding on almost 2,000 bird species.
Their prey size ranges from cranes to hummingbirds, but their prey includes gulls, ducks, pigeons, storm petrels, thrushes, jays and starlings, to name a few. Bats also make up a large contingent of their diet.
The Peregrine Falcon is a widespread species whose population is recovering after DDT poisoning caused the population to collapse in the mid-twentieth century. The current global breeding population is estimated to consist of 340,000 breeding individuals.
This species is threatened by illegal hunting, persecution, habitat destruction, egg collecting, human disturbance and poisoning in some areas.
Peregrine Falcons are usually found in almost any open habitat, but they are most likely to be seen over mudflats, in mountainous areas, on coastlines, and along rivers and lake edges. They also occur in valleys and gorges as well as urban environments such as cities.
Peregrine Falcons are found in California throughout the year and are common. However, many individuals are migratory and only occur in the state during winter. Along the coastal areas, they remain all year round.
Some good locations to find this species are Morro Bay, Yosemite National Park, Cabrillo National Monument, Bolsa Chica Ecological Reserve and Arcata Marsh and Wildlife Sanctuary.
2. American Kestrel
- Scientific name – Falco sparverius
- Lifespan – 5 years (average), 14 years (maximum recorded)
- Size – 8.7 to 12.2 in (22 to 31 cm)
- Weight – 2.8 to 5.8 oz (80 to 165 g)
- Wingspan – 20.1 to 24 in (51 to 61 cm)
- Status – Least concern
The American Kestrel is a small falcon with long, pointed wings and a long tail. Males have a rusty-coloured back with black bars and slate-blue wings, and the underside is whitish to rusty in colour.
The female is rusty-coloured throughout the body, with black bars on the back and wings. Both sexes have a grey crown and two black moustaches on the face.
The underwings of both sexes are well patterned in black and white. The call of the American Kestrel is a loud series of klee or killy notes.
American Kestrels nest in tree cavities and nest boxes. They do not build their own nests but instead rely on rock crevices, naturally formed tree cavities, old woodpecker holes and corners of artificial structures such as buildings. The most common locations for nest sites are in trees along the edges of woodland and trees over open spaces. The nest is a shallow depression made of any material found at the bottom of the cavity.
The female lays four or five eggs per clutch, and up to two clutches may be laid in a season. The eggs are white, yellowish or reddish-brown with grey or brown mottling. The eggs are incubated for 26 to 32 days, and once hatched, the hatchlings grow for an additional 28 to 31 days before they start learning to fly.
American Kestrels feed on invertebrates such as grasshoppers, beetles, cicadas, beetles, spiders, scorpions, moths, and butterflies. They also prey on mammals and birds, including mice, voles, bats, shrews, and songbirds. Occasionally, they may eat snakes, frogs and lizards.
American Kestrels have significant declines in the US over the past five decades, with a 53% reduction in population size. In saying that, the breeding population is still estimated to comprise 9.2 million individuals.
The continued declines are due to land clearing and chopping down of trees that the falcons use as nesting sites. Prey availability has also decreased because of the removal of dense vegetation in light of “clean” agriculture. Pesticides and pollutants also threaten this species because they kill the prey items on which they depend.
American Kestrels are found all across California all-year round, where they are common. They occur in open areas with short vegetation and scattered trees, such as grasslands, meadows, parks, deserts, agricultural land, suburban areas and cities.
The populations in southern California migrate north to breed during the summer months, so this species is less numerous at that time of the year. Some of the best locations for seeing this species are Andrew Molera State Park, Yosemite National Park, Point Reyes National Seashore, San Gabriel Mountains and Klamath Basin National Wildlife Refuges Complex.
3. Prairie Falcon
- Scientific name – Falco mexicanus
- Lifespan – 3 years (average), 17 years (maximum recorded)
- Size – 14.6 to 18.5 in (37 to 47 cm)
- Weight – 14.8 to 38.8 oz (420 to 1100 g)
- Wingspan – 35.4 to 44.5 in (90 to 113 cm)
- Status – Least concern
The Prairie Falcon is a medium raptor with long, pointed wings and a long tail. This species has a brown upperside and a pale, whitish underside with brown marks on the belly and breast. The underwing is dark from the “armpit” to the “wrist” of the wing. The unique dark underwing linings are the main field mark of this species while in flight.
They have a brown moustache and a pale line above the eye. The most common call produced by this species is a kik-kik-kik.
Prairie Falcons breed in open habitats, on cliffs and on bluffs. The nest is often placed in a pothole, in a crevice, on a cliff ledge, or a steep bluff with an overhang. They may occasionally nest in trees, buildings, caves, or power line structures.
The nest is a slight indentation made of loose debris. Sometimes, a pair may take over an abandoned corvid or eagle nest. The female lays two to six eggs in a clutch, producing only one clutch per season.
The eggs are creamy white or russet, with brownish spots. The incubation period lasts for 29 to 39 days. Once hatched, the chicks develop for 29 to 47 more days before they begin to fledge.
The Prairie Falcon diet consists of small mammals, especially ground squirrels and pikas. Birds such as shorebirds, doves, larks, meadowlarks and many other species, as well as insects, also make up part of their diet.
The global population seems to be stable at an estimated size of 80,000 breeding individuals. Pesticides like DDT and their derivatives threaten this species, while illegal hunting is also a factor causing decreases in their population size.
They are also impacted by habitat loss due to land conversion, mining practices, wildfires, and human disturbance at breeding sites.
The Prairie Falcon occurs throughout California and is primarily resident. They are a common species that increase in abundance during winter as individuals from other parts of the continent take on short-distance migrations.
They occur in various habitats, including shrubland, grassland, desert shrubsteppe, alpine tundra, and farmland. They can be seen in many areas, and some of the good locations are Klamath Basin National Wildlife Refuges Complex, Point Reyes National Seashore, Arcata Marsh and Wildlife Sanctuary, Andrew Molera State Park, and Elkhorn Slough National Estuarine Research Reserve.
- Scientific name – Falco columbarius
- Lifespan – 3 years (average), 11 years (maximum recorded)
- Size – 9.4 to 11.8 in (24 to 30 cm)
- Weight – 5.6 to 8.5 oz (160 to 240 g)
- Wingspan – 20.9 to 26.8 in (53 to 68 cm)
- Status – Least concern
The Merlin is a small with an overall dark body that may vary in colour with geographic location. They are usually grey on the upper side, with a thin line above the eye and a pale moustache, which is absent in some subspecies.
The wings and tail are long and dark. The underparts are heavily streaked. Females have brown bodies with heavily streaked undersides and a thin line above the eye. Adult males are bluish on the back. The Merlin makes a high-pitched chatter call.
Merlins breed in open and semiopen habitats in coniferous or deciduous trees and shrubs near water sources. They sometimes breed in cities, where they use crow nests in conifers. This species takes over abandoned hawk, raven, magpie and crow nests. Rarely, this species nests in tree holes, cliff edges or at ground level.
The nest is a shallow depression made in the substrate of the chosen nesting site. The female lays four to five eggs in a clutch and lays one clutch per season. The chestnut-marked brown eggs are incubated for 28 to 32 days. The period between the chicks hatching and fledging is a further 25 to 32 days.
The Merlin feeds on birds most of the time. Namely; larks, sparrows, waxwings, sandpipers and other shorebirds. Occasionally, they prey on insects and small mammals such as dragonflies and bats.
The Merlin is a widespread species that has increased in population size by almost 2% each year for the past five decades. This indicates that they are recovering well from declines induced by pesticides in the 1960s. The global breeding population is estimated to comprise 3.2 million individuals.
This species has benefited from breeding in urban areas where they have abundant food sources such as House Sparrows (Passer domesticus) and nesting sites in the form of crow nests. They are threatened by habitat loss and human disturbance in many areas. Illegal hunting and egg collection pose a threat too.
The Merlin is a migratory species that occurs throughout the state during the winter, non-breeding season. During summer, they are found further north in Canada, where they breed. They are reasonably common in some California areas but uncommon and unpredictable in most parts of the state.
While most individuals migrate out of the state for the summer, some remain in the state and may be seen occasionally. The habitat in which they occur is fragmented woodland areas close to rivers, bogs and lakes, along with deciduous tree forests and suburban and urban environments.
They also occur in grasslands, open forests, and coastal environments. This falcon can be seen at Bolsa Chica Ecological Reserve, San Gabriel Mountains, Cabrillo National Monument, Elkhorn Slough National Estuarine Research Reserve and Golden Gate National Recreation Area, amongst many other locations.
Falcons are a fascinating group of birds that fly at incredible speeds and have some of the most excellent eyesight and hearing senses of any animal. Many falcons are widespread and common, but they encounter many threats to their survival.
The four falcons in California are not currently threatened, but some of their populations were damaged by the use of pesticides in previous decades, which shows that a change in management and usage rules can have a severe effect on these enigmatic birds.
These birds may benefit from human development because it increases food and nest site availability. On the other hand, human encroachment can negatively impact species, particularly those that have not adapted well to human development.
Today, management practices are in place, along with laws to protect species such as the many falcons, and those should prevent further decreases in population sizes. These measures need to be maintained because these birds are a fragile group that relies on the health of their prey items that are often seen as pests and exterminated.
All-in-all, California is a must-visit state for anyone who desires to experience authentic, quality North American birding. The falcon species found in the state are fantastic to watch. While no falcons are in view, the vast bird diversity will keep any birder entertained at any top birding destinations.