Peregrine Falcon

Falco peregrines

By Andy McCormick

  • Length           14-18" long 
  • Wingspan     37-46"
  • Weight          1-2 lbs.
  • AOU Band code    PEFA
     

The genus name falco is Latin for falcon, from the Latin falx, an agricultural tool with a curved blade, such as a scythe or sickle, which refers to the long toes with sharply curved talons.  The species name is from peregrinus also from the Latin for foreign or exotic.  It refers to the wandering nature of this bird (Holloway, 2003).  Indeed, these birds with straight, pointed wings are compact, muscular and very fast flyers.  They can cover great distances very quickly, and have been clocked at speeds in excess of 200 mph when in a steep dive called a stoop.  They hunt other birds while they are in the air.  They attack first with one foot stunning the bird and then have the option of grabbing on with the other foot.  They will typically sever the bird’s spinal cord at the neck with their beak on a perch or on the ground.  They are a spectacular bird both in flight and on the perch.  They are a worldwide species and are seen year-round along Puget Sound and on the Olympic Peninsula and during migration in Eastern Washington. 

The black “mustache” on the malar feathers just behind the bill is diagnostic for identifying a Peregrine at close range.  The smooth slate-gray back can make identification from a rear view a bit difficult as we learned on a recent trip.  From a long distance many mistook the Peregrine for a Merlin, which also has a dark back in the western U. S.  Merlins can reach 12 inches in height, and a smaller male Peregrine at around 14 inches can create some confusion. The throats of adult Peregrines are white with many having white breasts as well and there is clear barring across the belly all the way to the under tail area.  Peregrines for centuries have nested on cliffs in caves or small holes.  Sometimes they “borrow” a nest.  They incubate 2-5 burnt red and brown speckled, cream-colored, ovate eggs about the size of a hen’s egg in a shallow nest of gravel or sticks.  Pete Dunne (1995) describes Peregrine eggs as “having the luster of polished stone.”  The eggs were highly sought by collectors.  The parents mate for life and divide the labor with the male hunting and the female tending the nest.  The chicks hatch in 30-34 days.   

Aggressive conservation efforts since the 1970s saved these remarkable birds from probable extinction.  Pesticide poisoning and nest failure due to egg-thinning caused by DDT  led to a steep decline in population.  They have adapted well to city living and are now found nesting on bridges and tall buildings.  With a ready supply of pigeons for food, the Peregrine Falcon may well be an exciting addition to the urban birding scene for years into the future.  

Photo by Tyler Hartje

Photo by Tyler Hartje

American Kestrel

Falco sparverius

By Andrew McCormick

  • Length           9 in 
  • Wingspan     22 in
  • Weight          4.1 oz (117 g)
  • AOU Band code    AMKE

If you see a small, long-winged bird hovering over an open field, most of the time it will be an American Kestrel. This type of hunting pattern is used by only a few species of birds and it is a trademark for a kestrel, which hovers by facing into the wind, flapping its wings and spreading its tail. It will glide to a new location and hover again to detect grasshoppers, other large insects and sometimes small rodents. The kestrel will also frequently be seen perched on a wire or exposed branch from where it will swoop down to catch prey.

The American Kestrel is sexually dichromatic. The male has grey-blue wings which contrast with its rufous back and a rufous tail with a black terminal band. The female has rufous wings barred with black. The tail is also rufous with black bands along its length (Smallwood & Bird). Both male and female have black moustachial stripes and a vertical black mark behind the eye giving them a striped-head look. The bill is small and the feet and legs are yellow.

There are nine North American falcons in the genus Falco, from the Latin falx, an agricultural implement with a curved blade, a scythe or sickle. The American Kestrel has the species name sparverius. In Early Modern English this was the term for Sparrow Hawk, which is still used as a common name for this bird. Kestrel is from the French, crecelle, a noisy bell, referring to its call, which is a high-pitched, loud and ringing killy-killy-killy-killy-killy (Holloway, Alderfer).

The American Kestrel is a cavity-nester using natural openings in trees (or cactus in the southwest), spaces between rocks, nooks in structures, and holes excavated by woodpeckers (Smallwood & Bird). Kestrels will readily use nest boxes when they are placed high in a tree. The birds do not build a nest but will make a scrape in whatever material is already in the cavity. Typically, 4-6 whitish, spotted eggs are deposited and then incubated by both parents for about a month. First flight occurs in another month with the parents continuing to feed the young kestrels for another 12 days.

Migration occurs in stages with northern breeding birds migrating first and others following in waves. It is thought that migration is stimulated by changes in available light. Kestrels can be seen in Washington year-round with some breeding in the state and others wintering from northern areas.

Two studies indicate that the life span for an American Kestrel may be between 1-2 years. However, average life span in captivity is five years. The North American population has changed in response to human intervention. Deforestation and farming increased kestrel habitat but forest regrowth, increased urbanization and sprawl has reduced open field acreage. Overall the American Kestrel has a stable population and remains our smallest, most widespread and well-loved falcon.

Photo by Mick Thompson

Photo by Mick Thompson

Gyrfalcon

Falco rusticolus

By Hugh Jennings

  • Length           22" long 
  • Wingspan     47"
  • Weight          3.1 lb. (1400 g)
  • AOU Band code    GYRF

The Gyrfalcon (GYRF) is about 22” long with a wingspan of 47” and weight of 3.1 lb. (1400 g).  It is the largest falcon in the world.

The genus name Falco (FAL-koh) is Latin for hawk, referring to the hooked (falcate) shape of the claws. The species name rusticolis (russ-TICK-oh-lus) is from the Latin rusticola, living in the country. The common name (JER-fall-kon) is from Latin gyrfalcon, or girofalco, said to be a Low Latin corruption of hierofalco, or “sacred falcon” for a bird so highly revered by falconers. This swift, powerful species is mostly found on the Arctic tundra. Most of the Gyrfalcons are an overall gray, but there white and dark morphs. The white morph nests primarily in northern Greenland, while the dark morph nests in Labrador. The gray morph is widespread and is the one that occurs in the Pacific NW. It is a heavy-bodied falcon with long, broad wings with pointed tips and a relatively long tail. The gray morph has gray upperparts, a whitish body with gray spotting or streaking on the breast and belly. Sometimes a weak, or thin, mustache is visible. It is usually found in open and semi-open areas, such as marshes, fields and wetlands where prey is abundant. Most of the Gyrfalcons remain in the far north all year. Only a few come as far south as the Canadian border in winter. West of the Cascades the GYRF is a rare winter resident on the Samish and Skagit Flats, Dungeness Spit and Ocean Shores. In Eastern Washington they are most likely seen on the Waterville Plateau, Davenport-Reardan area and north of Moses Lake. They do not nest in Washington. Most of the Gyrfalcons seen in Washington are immatures which are more  brown overall instead of gray. There is a lot of pressure worldwide on Gyrfalcons as they are collected from the wild and sold to falconers in other countries for large sums of money.

In Alaska, the GYRF feeds mostly on birds, mainly on ptarmigans and grouse. Some of the mammals used for food are lemmings, squirrels and hares. In Washington they feed mainly on waterfowl, upland game birds such as Ring-necked Pheasant and Gray Partridge, shorebirds and Rock Pigeon. They hunt by scanning the area from a perch on a high rock or while flying. It most often attacks in a level chase low over the ground and simply outflies its prey, often attacking from below. It strikes in mid-air and then carries the prey or follows it to the ground. Their alarm call is a loud kak-kak-kak or harsh kikikikiki. Gyrfalcons nest in the Arctic tundra and and use cliff sites or old nests built by other birds in spruce or poplar trees, such as ravens or Golden Eagles. They do not add material to existing nests. Three to four white or creamy white eggs  spotted with reddish brown are usually laid. Incubation is by both parents, but mainly by the female, and lasts about 35 days. For the first 1-3 weeks the young are brooded mostly by the female. The male does most of the hunting and brings food to the female which she feeds to the nestlings. The female begins hunting after about 2-3 weeks. The young make their first flight after about 45-50 days.

Sharp-shinned Hawk

Accipiter striatus

By Andrew McCormick

  • Length           11 in 
  • Wingspan     23 in
  • Weight          5 oz (140 g)
  • AOU Band code    SSHA

Our smallest accipiter, the Sharp-shinned Hawk, commonly known as the “Sharpie” is a bird of the forest. It is compact, quick and agile with short wings and long tail that help it navigate in wooded areas where it hunts small birds. It breeds in the Boreal Forest and in the forests along the Cascade Range in Washington and the Rocky Mountains. In winter it can be found in urban areas and is often seen capturing small birds at backyard feeders.

This True Hawk is a Sprinter

The Sharpie shares the genus Accipiter, the Latin word for a bird of prey, with the Cooper’s Hawk and the Northern Goshawk. Its species name striatus is Latin for furrowed or striped, referencing the stripes on the hawk’s underside (Holloway). It is not clear if the reference is to the horizontal barring on the adult or the vertical streaking on the juvenile.

It attacks its prey with a quick burst from hiding. It will approach prey from a low branch or low level flight. They are also seen running under shrubbery after Dark-eyed Juncos and sparrows. They have also adapted to human-made structures and will use them to hide in wait for prey (Bildstein and Meyer). Once begun, the chase will be spirited and, if the Sharpie misses its mark, the pursuit will end quickly. There are no long chases through the bushes (Dunne, Sibley, and Sutton). 

Secretive Forest Breeder

The Sharp-shinned Hawk nests in mixed or coniferous forests. The nest site is well-concealed and the Sharpie is very secretive during the breeding season. Observers note that the nest is a platform of sticks often built on top of an old nest of a squirrel or crow. Usually 4-5 bluish-white and brown-splotched eggs are deposited. Incubation lasts about a month and during this time the male brings food to the female on the nest. As the nestlings grow, the male will bring food to the nest, but the female will feed them. The young will move to nearby branches in 3-4 weeks and fly in 5-6 weeks after hatching (Kaufman).

The Sharpie makes a diet of mostly sparrow and warbler size birds, but robins make up a large portion of the diet. At times the diet varies to add bats, small rodents, snakes, and lizards. Females often take heavier prey than the males (Bildstein and Meyer). This difference in foraging provides a wider range of food available to the pair.

Migration in Numbers

Sharpies are regularly seen in fall migration usually during the first three weeks of October. Many Sharpies in the Northwest are year-round residents, but most North American Sharp-shins migrate long distances and are seen at hawk watch stations. They migrate individually or in small groups, but over the course of some days dozens may be seen mixed with Broad-winged and Red-tailed Hawks. The Sharp-shin’s migration is timed to coincide with that of passerines, which they hunt while migrating.

There has been an increase in numbers of Sharp-shins recorded during Christmas Bird Counts north of the usual monitoring stations and this may explain some reduction in the numbers of Sharpies seen at the stations. Some suggest that increased use of bird feeders as sources of prey may cause short stopping of migration (Bildstein and Meyer). More knowledge of these patterns is needed, but may be difficult to obtain as the Sharpie is one of the most difficult birds to count in a census.

A Note on Identification

“Distinguishing one accipiter from another is not easy. It is in fact, one of the most difficult identification problems facing hawk watchers. Even veteran observers do not always agree,” (Dunne, Sibley, and Dutton). The Sharp-shinned Hawk has a variety of different sizes and appearances. The males are about two-thirds the size of the females. Plumages also differ. Adults have rufous barring on the chest. Juveniles have brown streaking on the chest extending to the belly. Juveniles also have a different shape than adults have. I recommend two books that I have found helpful in learning more about identification of accipiters.

 

Dunne, P, Sibley, D. & Sutton, C. (1988). Hawks in flight. Boston: Houghton Mifflin.

Wheeler, B. K. & Clark, W. S. (1995).  A photographic guide to North American raptors.  Princeton:  Princeton Univ. Press.

 

Rough-legged Hawk

Buteo lagopus

By Andrew McCormick

  • Length           21 in 
  • Wingspan     53 in
  • Weight          2.2 lb (990 g)
  • AOU Band code    RLHA
     

If you are driving in open country in Washington in winter and see a large light-colored raptor perched on a shrub, it is likely to be a Rough-legged Hawk.  They hunt from low perches or low flight and feed on voles, ground squirrels, mice and sometimes birds it can find on the ground.  They are winter visitors to Washington and can be found in the Skagit Flats in Western Washington and in many places in Eastern Washington in their preferred habitat of open grasslands, brush country and sometimes marshes.

The Rough-legged Hawk is our most northern buteo (pronounced byoo’-tee-oh) having evolved in the circumpolar arctic. In North America the area includes the tundra north of the boreal forest in a wide expanse from Alaska across Canada.  The entire population migrates in late fall to southern Canada and northern United States.

Rough-legged Hawks can be found in both light and dark morphs, with the latter making up almost forty percent of the birds in the east, but only ten percent of those in the west.  The adult light morph Rough-leg will almost always have a light forehead and in general the head will be light colored, differentiating it from the darker headed Red-tailed Hawk.  Most Rough-legs seen in western Washington will have large black carpal patches at the bend or wrist on the underside of the wings.  The wings have a black trailing edge formed by the black tips of the feathers.  The female has a wide black subterminal band on the tail and the male can have several black tail bands (Bechard & Swem).  These raptors have the smallest feet of any of the buteos (Alderfer).

The birds belong to the genus Buteo which is Latin for a species of hawk or buzzard.  Buteos are characterized by large bodies and long, wide, rounded wings on which they soar.  The species name lagopus, hare’s foot, is from the Greek, lagos, a hare, and pous, foot giving reference to the feathered-covered legs.  Rough-legs have feathers all the way to the toes, an adaptation that helps them retain heat in the arctic. Hawk is from the Anglo-Saxon hagoc (Halloway). 

Rough-legs are cliff dwellers and will alternate nesting sites with Gyrfalcons and Peregrine Falcons (Dunne, Sibley & Sutton).  The Rough-leg’s nest is most often built on a cliff but at the edge of the forest it can be in a tree.  It is a mass of sticks and debris lined with grasses.  Usually 3-5 pale bluish-white eggs are deposited.  Incubation is mainly by the female and the eggs hatch in a month.  The first flight will occur after 5-6 more weeks.  Rough-legs eat large numbers of lemmings and other rodents and the success or failure of nests can vary with the yearly fluctuations of their supply of prey.

The remoteness of their nesting sites has protected them from human activity and the Rough-legged Hawk population is doing very well.  Their greatest threats are on the wintering grounds which are heavily used for agriculture.  

Photo by Mick Thompson

Photo by Mick Thompson

Northern Harrier

Circus cyaneus

By Andy McCormick

  • Length           18" long 
  • Wingspan     43"
  • Weight          15 oz. (420 g)
  • AOU Band code    NOHA

The Northern Harrier is the bird of many names. It is the Marsh Hawk which cruises low over marshes and fields. It is the Hen Harrier, as it is called in Europe and Asia, presumably because it made off with a hen every now and then. Most gloriously, it is the Sky Dancer. In spring the male Northern Harrier will circle high into the sky and just as it seems it will keep going up, it performs a somersault and dives in a dramatic swoop almost to the ground and then circles up again. The dancing is part of its courtship display. It must be effective, because male harriers are polygamous and will mate with several females, sometimes as many as three at one time. Pete Dunne says, “the sky dancing is a way of saying, ‘I’m the hottest, spunkiest, most capable (and most eager) harrier in the marsh.”

The responsibility of nurturing the offspring in multiple nests keeps the male very busy once the chicks hatch out. Harriers nest on the ground in a dense field or marsh. The nest is a shallow depression lined with grass. Generally 4-6 eggs are incubated by only the female for about a month. It takes the young another month to take flight so they are fed by parents during that time (Kaufman). The nest may be part of a loose colony, especially if the male has mated more than one female. Unlike many raptors, harriers will overlap their foraging area as they quarter fields in low flight (Dunne).

This flight pattern led to its name.  Harrier refers to the bird’s “hunting behavior of flying close to the ground and harrying its prey” (Holloway). The Northern Harrier is the only North American representative from the genus Circus from the Greek kirkos, a circle or ring, for a kind of hawk that flies in circles. There are 14 species of harrier worldwide. The species name cyaneus, dark blue, references the bluish gray color on the back of the male Northern Harrier. The most obvious and helpful field marks for identification are the white upper tail coverts, often called a “rump patch,” which are visible in flight on both the male and female.

Northern Harriers share hunting areas with owls, often Short-eared Owls, with which they bear a striking resemblance when seen face on. Both species have a facial disk that focuses sound waves allowing them to track prey in the grass. They may eat songbirds and doves, voles and other rodents, small rabbits, insects, and snakes, lizards, frogs and toads (Kaufman).

North American Northern Harriers migrate through the central part of the continent, but significant numbers are seen along the Pacific Flyway in SE Alaska and British Columbia in both fall and spring. Some will overwinter in Washington. Most migrate to the southern United States and into Mexico. The population of Northern Harriers varies with availability of prey, chief of which are voles. In the 20th Century overall populations have declined primarily from loss of habitat due to draining of wetlands, monotypic farming and reforestation of farmlands. Since the 1990s continent-wide population has been fairly stable (Smith, et al).

You can see a male harrier soaring with a hint of sky dancing at Macauley Library.

Photo by Mick Thompson

Photo by Mick Thompson

Merlin

Falco columbarius

By Hugh Jennings

  • Length           10" long 
  • Wingspan     24"
  • Weight          6.5oz. (190 g)
  • AOU Band code    MERL

The Merlin (MERL) is about 10" long with a wingspan of 24" and a weight of 6.5 oz. (190g). The genus name Falco (FAL-koh) is Latin for hawk, referring to the hooked (falcate) shape of the claws. The species name columbarius (koh-lum-BAY-rih-us) is Latin, pertaining to doves. Its former common name was pigeon hawk because it killed pigeons.

The Merlin is a small falcon with a weak or indistinct mustachial stripe. It is small, compact, powerful and very aggressive. The wings are short and pointed, always angular and most appear dark. It is found in wide-open spaces and open woods and captures birds and insects in midair by a level sprint, ending up with abrupt turns. It has been said that it flies straight like a bullet.

There are three populations that differ in overall color. The Pacific (Black) race is very dark. Males are blue-gray above and have dark brown streaking below. Females are dark brown above with heavy brown streaks below.The Black race winters along the Pacific coast south to California, rarely east to New Mexico. Taiga race sometimes resembles the Black, but the tail is dark with narrow gray bands in tail and pale, buffy undertail and weak mustache. The Taiga birds are widespread and winter along both coasts. The Prairie race is the lightest color and has wide gray bands in tail. This race winters from Canada to Mexico, sometimes west to California

The Merlin feeds primarily on birds, but also on rodents, lizards, snakes and insects. A variety of elaborate aerial maneuvers and calls are used in courtship displays. Food collected by the male may be passed on to the female in midair. The alarm call is a rapid, accelerating series of strident notes, rising then falling, "kikikikiki."

They use the abandoned nest of another bird, a cavity in a tree or cliff, or the ground with no nest materials except for a few green twigs. There are 2 to 7 white eggs with dark marks. Incubation period is 28-32 days and the young fledge 25-35 days later. Incubation is mostly by the female, but the male brings food to the female and incubates while she eats. The female remains with the young most of the time, brooding them when they are small. The male brings food which the female takes from him near the nest and feeds it to the young.

Most of the Pacific Northwest birds are permanent residents. Most other Merlins migrate, some as far as South America. Some prairie birds have become permanent residents in cities on the northern plains.

Photo by Mick Thompson

Photo by Mick Thompson

Bald Eagle

Haliaeetus leucocephalus

By Andrew McCormick

  • Length          31 in
  • Wingspan    80 in
  • Weight         9.5 lb
  • AOU Band code   BAEA

One of eight species of sea eagles in the world from the genus Haliaeetus from the Greek aliaetos, the sea eagle.  It is named for its white head; again from the Greek -  leukos, of the color white, and kephale, head.  Its common name refers to a Middle English interpretation of balled meaning shining or white (Holloway, 2003).  The adult Bald Eagle is unmistakable with its large white head and tail contrasting with its dark brown, bulky body.  The bill and eyes are yellow.  It soars on wide flat wings and flies using slow, heavy and powerful wingbeats.   Its call is surprisingly weak for such a large bird.  Various authors describe it as thin and hollow (Alderfer), flat (Sibley) and a mixture of squawks and shrieks ( Bell & Kennedy).   Immature birds lack the white head and tail and develop through four stages reaching full maturity in their fifth year.  The juvenile through fourth-year birds have varying amounts of white in the belly and underwing coverts and axillaries. 

 

Coastal Bald Eagle migration will follow the salmon runs.  Some Pacific Northwest birds will fly north in late summer to catch early salmon migrations and then joined by Alaska birds will follow the salmon south and winter in the Pacific Northwest beginning in November.   Fish are their preferred food especially while nesting, but they are opportunistic hunters and will snag an array of fish, waterfowl, and mammals with their talons while in flight.  They are quite adept at kleptoparasitism and will steal kills from other raptors particularly osprey.   Carrion also makes up a portion of their diet.

 

Bald Eagles nest in an aerie, a large nest near the crown of very large trees or on rocky pinnacles.  Built with sticks the nest will be reused for several years growing larger each year.  An old eagle nest can be huge; weigh hundreds of pounds and measure 8-10 feet in diameter.  They are sometimes used by Great Horned Owls.  The nest of sticks is lined with grasses, moss and sod.  The clutch is usually two dull white eggs, which are incubated by both adults for about 35 days.  Juvenile birds make their first flight in 10-12 weeks. 

 

Human beings have been the greatest source of mortality for Bald Eagles.  They have been killed as perceived threats to livestock and for their feathers for ceremonial purposes.  Pesticides caused egg shell thinning and eagle populations plummeted from the 1960s to 1980s.  Diligent conservation efforts have been very successful and Bald Eagles are now nesting in every state and the bird has been removed from the Endangered Species list.   The species has developed more tolerance to human activity and birds are now seen in inland waterways near cities.

 

A variety of audio and video recordings of Bald Eagles can be found at the Cornell Lab of Ornithology Web site at the following address.  Cat# 4334 has a good variety of calls. 

http://animalbehaviorarchive.org/assetSearchInterim.do

Photo: Bald Eagle, by Tyler Hartje

Photo: Bald Eagle, by Tyler Hartje

Cooper's Hawk

Accipiter cooperii

By Andy McCormick

  • Length           Female 42-47 in, Male 37-41 in 
  • Wingspan     Female 79-87 in, Male 70-77 in
  • Weight          Female 17-24 oz (479-678 g)
  •                        Male     10-14 oz (302-402 g)
  • AOU Band code    COHA