Iowa may be known as a land of agriculture, but the state also holds a variety of natural habitats such as forests, lakes, prairies and wetlands. These habitats attract many bird species, with over 430 species recorded in the state. Amongst the great total number of birds are the hawks.
Hawks are birds of prey that belong to the Accipitridae family. They are diurnal predators with exceptional vision and hearing, making them extremely resourceful hunters. Sexual dimorphism is often seen amongst hawks, with female hawks being larger than their male counterparts.
In Iowa, ten hawk species may be spotted throughout the year, but the abundance and species composition change with the seasons as hawks migrate to and from the state. Birding areas in the state are diverse, but some of the best birding locations are found on the eastern and western borders of the state where the Missouri and Mississippi Rivers flow.
Specific areas are Yellow River State Forest, Hitchcock Nature Area, Neal Smith National Wildlife Refuge, Great River Birding Trail, Dewey’s Pasture, Cone Marsh Wildlife Management Area, Saylorville Reservoir, Hawkeye Wildlife Management Area, Red Rock Reservoir, Ada Hayden Heritage Park, and Deere Dike.
In the following text, we will look closely into the ten types of hawks in Iowa and where to find them.
1. Sharp-shinned Hawk
- Scientific name – Accipiter striatus
- Lifespan – 5 years (average), 12 years (maximum recorded)
- Size – 9.4 to 13.4 in (24 to 34 cm)
- Weight – 3.1 to 7.7 oz (87 to 218 g)
- Wingspan – 16.9 to 22.1 in (43 to 56 cm)
- Status – Least concern
The Sharp-shinned Hawk is a small, long-legged hawk with a small head and a long tail. It has a blue-grey upperside and a horizontally barred red-orange breast.
These hawks have short, round wings that the head does not extend past in flight – a feature that distinguishes this species from the Cooper’s Hawk. The sound produced by this species is a series of kik-kik calls made during courtship.
Sharp-shinned Hawks build their nests at the top of tall trees under the canopy, between the tree trunk and limbs extending horizontally.
This species makes a wide stick nest that is lined with bark pieces. The female of the species lays between three and eight white or spotted blue eggs, which are incubated for 30 to 35 days. The hatchlings take 21 to 28 days to develop enough to fly.
Sharp-shinned Hawks feed almost exclusively on small songbirds, including robins, sparrows, thrushes and warblers. On rare occasions, they may eat larger birds such as doves, woodpeckers, and swifts. Mammalian prey includes mice and voles, and they also prey upon insects.
The Sharp-shinned Hawk population is currently stable and estimated at approximately 1 million breeding individuals. These hawks are threatened by pesticides such as DDT, which builds up in their prey items that migrate from South America, where DDT is sometimes used. Illegal hunting and shooting are still threats in some areas too.
The advent of increased bird feeder use may have allowed the hawks to stabilise their populations because of the more accessible access to prey items that are attracted to the feeders.
Sharp-shinned Hawks are found along forest edges and in suburban areas such as yards. In Iowa, they are mostly seen during winter from September to April, when they migrate from their breeding grounds further north and can be relatively common.
This species may be seen in many areas of the state, including Hitchcock Nature Area, Red Rock Reservoir, Deere Dike, Saylorville Reservoir, and Hawkeye Wildlife Management Area.
2. Cooper’s Hawk
- Scientific name – Accipiter cooperii
- Lifespan – 12 years (average), 20 years (maximum recorded)
- Size – 14.6 to 17.7 in (37 to 45 cm)
- Weight – 7.8 to 24 oz (220 to 680 g)
- Wingspan – 24.4 to 35.4 in (62 to 90 cm)
- Status – Least concern
Cooper’s Hawks look similar to Sharp-shinned Hawks but are more substantially sized. Cooper’s Hawk has a blue-grey back, a black cap, a red eye, an orange-red breast and dark banding on the tail.
Another way to separate the two species is that the head of this species extends far more extensively past the wings than that of the Sharp-shinned Hawk. The wings and tail are rounded, and a white terminal band is found on the tail tip.
Cooper’s Hawks produce a grating cak-cak call that lasts for up to five seconds, usually heard during courtship.
Cooper’s Hawks nest in tall trees, in which they usually build the nest on an old nest made by a larger bird or on a mistletoe cluster, about two-thirds of the way up the tree, or on a horizontal branch. The nest is a stick nest that is lined with pieces of bark or green twigs.
The female lays two to six bluish-white or pale blue eggs in a clutch. Incubation occurs for 30 to 36 days, and it takes a further 27 to 34 days after hatching for the hatchlings to fledge.
Cooper’s Hawks feed on small and medium-sized birds and small mammals. Avian prey items include jays, robins, starlings, pigeons, doves, woodpeckers and quails. Mammalian prey comprises squirrels, hares, mice, bats and chipmunks.
Cooper’s Hawk populations have increased over the past five decades, and the breeding population is estimated at 1 million. In the past, DDT pesticide was a grave threat along with shootings which caused their populations to decrease drastically, but the populations have recovered well. Many deaths occur in urban areas from windows and car strikes.
Cooper’s Hawks remain year-round in the state. This common but secretive species appears to be seen more frequently in winter, when more birds may be present in the state after some migrate south from their northern breeding range.
They are often seen in forests, woodlands, woody suburbs and yards containing feeders for their bird prey. Located across most of the state, specific areas to look for this species in Iowa are Hitchcock Nature Area, Saylorville Reservoir, Red Rock Reservoir, Hawkeye Wildlife Management Area and Ada Hayden Heritage Park.
3. Northern Goshawk
- Scientific name – Accipiter gentilis
- Lifespan – 7 years (average), 17 years (maximum recorded)
- Size – 20.9 to 25.2 in (53 to 64 cm)
- Weight – 22.3 to 48.1 oz (631 to 1364 g)
- Wingspan – 40.5 to 46.1 in (103 to 117 cm)
- Status – Least concern
The Northern Goshawk is a large raptor with a finely barred grey belly, a slate grey cap and back, a red eye and a distinct white eyebrow.
The wings are round and broad, and the tail is long. The Northern Goshawk makes a ki-ki-ki call when alarmed.
Northern Goshawks make their nests in forests with a clearing in the canopy caused by a trail, a road, or a naturally formed opening.
The nesting tree is usually large, and the nest is placed on a large branch or crotch next to the trunk. A goshawk pair may reuse the same nest for many years or commandeer nests from other Accipiters.
The stick nest is lined with fresh green material and bark. The female lays two to four bluish-white eggs in a clutch and incubates them for 28 to 38 days. Once hatched, the hatchling takes 34 to 35 days to fledge.
The Northern Goshawk feeds on an extensive range of prey items, including birds, reptiles, mammals, insects and even carrion. The mammal prey items consist of hares, ground squirrels, jackrabbits, and cottontails. Birds that are eaten include many species of grouse, woodpeckers and corvids.
The Northern Goshawk is an uncommon species which is widespread and secretive. The population is thought to be stable, comprising 420,000 breeding individuals.
The hunting prowess of the Northern Goshawk made it targeted by poultry farmers and were shot because they were deemed a threat to the livestock. The main threat that this species currently faces is logging and habitat destruction.
Northern Goshawks are very rarely seen in Iowa, but birds may be seen during winter (from September to May) when they move out of the breeding grounds further north.
They occur in old-growth and mature forests that have a mostly closed canopy. There have been many once-off sightings throughout the state.
Some locations where they could be seen are Red Rock Reservoir, Ada Hayden Heritage Park, Deere Dike, Saylorville Reservoir and Hitchcock Nature Area.
4. Red-shouldered Hawk
- Scientific name – Buteo lineatus
- Lifespan – 10 years (average), 25 years (maximum recorded)
- Size – 16.9 to 24 in (43 to 61 cm)
- Weight – 17.1 to 27.3 oz (486 to 774 g)
- Wingspan – 37 to 43.7 in (94 to 111 cm)
- Status – Least concern
The Red-shouldered Hawk is a medium-sized raptor with broad wings and a long tail. The underparts are reddish-brown, while the tail and flight feathers are white with black bands.
The upper side is a checkered dark brown and white pattern. The call of the Red-shouldered Hawk is a loud repeated kee-aah.
The Red-shouldered Hawk makes a stick nest that is lined in lichens, bark or moss. The nest is placed at the top of a tree with broad leaves – close to the main trunk. The female lays two to five white or faint bluish eggs with blotches in a clutch. The eggs are incubated for 32 to 40 days, and it takes a further 42 to 49 days after hatching for the chicks to eventually fledge.
The Red-shouldered Hawk’s diet mainly consists of birds, small mammals, reptiles and amphibians. Particular prey items include crayfish, voles, chipmunks, sparrows, starlings, doves, snakes and toads.
The Red-shouldered Hawk is a common species which has shown a 2% per year increase in population size over the past five decades. It is estimated that the total population size numbers 1.9 million individuals. The gravest threat this species faces is the destruction and clearing of woodland and forest habitat.
Red-shouldered Hawks are found in forests including bottomland hardwood, deciduous swamps and upland mixed deciduous-conifer forests. They also occur in suburban areas with woodland. In Iowa, they are uncommon but can be seen throughout the year.
The following are good areas to look for this species: Great River Birding Trail, Saylorville Reservoir, Yellow River State Forest, Hawkeye Wildlife Management Area, and Ada Hayden Heritage Park.
5. Broad-winged Hawk
- Scientific name – Buteo platypterus
- Lifespan – 12 years (average), 18 years (maximum recorded)
- Size – 13.4 to 17.3 in (34 to 44 cm)
- Weight – 9.3 to 19.8 oz (265 to 560 g)
- Wingspan – 31.9 to 39.4 in (81 to 100 cm)
- Status – Least concern
The Broad-winged Hawk is a small hawk species with broad, dark-outlined wings and a well-banded tail. The head and back are brown, and the underparts are brown with barring.
Rare dark-morph birds may be seen and are dark brown throughout their body. Broad-winged Hawks produce a sharp whistle – sounding like kee-eee.
The Broad-winged Hawk chooses nesting sites that are often near an opening in the forest, close to a water body. The nest is made from sticks and is usually placed on horizontal branches against the tree trunk or in the first large crotch of a tree – often found in the lower third of the forest canopy.
The nest is usually lined with materials such as lichen, pine needles, moss and feathers. Nests are often reused annually. A clutch usually contains one to five white, bluish or creamy-coloured eggs that are incubated for 28 to 31 days. Once hatched, the chicks fledge after 35 to 42 days.
Broad-winged Hawks feed almost exclusively on small mammals, insects and amphibians. The most commonly preyed upon items are small rodents, frogs and toads.
The Broad-winged Hawk is a common species which has increased in population size over the past several decades.
The population is estimated to comprise 1.9 million breeding individuals. This species is threatened by habitat destruction for development and human disturbance. Hunting is also a threat to this species during migration.
Broad-winged Hawks can be found in extensive mixed or deciduous forests. This species breeds in Iowa and can be seen in summer during the months of April to October. They migrate out of the state for the winter months.
The best places to try and find this species in the state are Hitchcock Nature Area, Saylorville Reservoir, Deere Dike, Hawkeye Wildlife Management Area, and Ada Hayden Heritage Park.
6. Swainson’s Hawk
- Scientific name – Buteo swainsoni
- Lifespan – 16 years (average), 26 years (maximum recorded)
- Size – 17 to 22 in (43 to 56 cm)
- Weight – 17.6 to 59.2 oz (500 to 1700 g)
- Wingspan – 46 to 54 in (117 to 137 cm)
- Status – Least concern
The Swainson’s Hawk is a long-winged, medium-sized raptor with a short tail. This species has variable plumage colours, but most individuals have whitish bellies, a reddish-brown chest and brownish-grey upper parts.
The underwings are lined in white, and the flight feathers are blackish. The head is brown on females and grey on males. Dark morph individuals are dark overall with a reddish-to-black colouration. The call of the Swainson’s Hawk is a shrill kreeee.
The Swainson’s Hawk constructs a nest from sticks and debris like wire and rope. The nest is lined with grass, hay, leafy twigs or bark. The nest may be reused from the previous year, or this species may fix an abandoned nest made by a corvid species.
The nest is usually placed close to the top of a tree, near a stream. The female lays up to five whitish, blotched eggs per clutch, and the eggs are incubated for 34 to 35 days. Once hatched, the chicks develop for a further 17 to 22 days before they fledge.
Swainson’s Hawks feed on mammals and insects mainly. Mammals make up the majority of their diet during the breeding season, and the prey items include mice, bats, voles, gophers, rabbits and ground squirrels.
In the non-breeding season, they feed on insects mainly. These include dragonflies, grasshoppers, crickets, beetles, moths and butterflies.
Swainson’s Hawks have increased in number over the past five decades, with an estimated increase of 1% per year. The population of breeding individuals is estimated at 900,000. This species has been persecuted and shot in the past, leading to decreases in population size.
Threats currently are a reduction in nesting sites and prey availability. Pesticides such as DDDT are mostly banned from use in many areas, but they still pose a threat to this species.
Swainson’s Hawks occur in open areas, including prairies, grasslands, and agricultural regions. In Iowa, they may be seen during summer from April until October, when they breed but remain uncommon. In winter, they migrate to South America.
Sites to look for this species in Iowa include Hawkeye Wildlife Management Area, Ada Hayden Heritage Park, Hitchcock Nature Area, Swan Lake State Park and Saylorville Reservoir.
7. Red-tailed Hawk
- Scientific name – Buteo jamaicensis
- Lifespan – 7 years (average), 30 years (maximum recorded)
- Size – 17.7 to 25.6 in (45 to 65 cm)
- Weight – 24.3 to 51.5 oz (690 to 1460 g)
- Wingspan – 44.9 to 52.4 in (114 to 133 cm)
- Status – Least concern
The Red-tailed Hawk is a large hawk characterised by its short, broad red tail. It is a broad-winged bird with a brown back and a pale underside showing a dark band on the belly.
The head is brown, and the throat is white. The Red-tailed Hawk call is one that many people have heard, even without knowing it was from this species. It produces a high-pitched, rough-sounding kee-eeee-arr that is often used as the call for birds of prey in movies.
The Red-tailed Hawk nests in tall trees, cliff edges, towers, and tall buildings. Their most usual nesting location is the top of a tall tree. The nest is made from sticks, and they often use the same nest over many years, refurbishing it each season.
The nest is lined with pieces of bark and fresh and dry vegetation. The female lays two to five brown-spotted whitish eggs. The incubation period is 28 to 35 days and the time taken before fledging is an additional 42 to 46 days.
Red-tailed Hawks primarily feed on mammals such as mice, voles, rabbits, wood rats, hares, ground squirrels and jackrabbits. Birds on which this species preys are namely, starlings, pheasants and blackbirds. They also sometimes eat carrion and snakes.
The Red-tailed Hawk is a common species that has increased by 1.3% each year since 1966, and the population is estimated to comprise 3.1 million breeding individuals. This species is threatened by human disturbance at nesting locations, hunting, and vehicle collisions.
Red-tailed Hawks are the most frequently seen raptors in Iowa during every season. This migratory species increases in number inside the state during winter as more birds arrive after breeding further north. Red-tailed Hawks are most often seen over open fields, but they also inhabit deserts, grasslands, scrublands, parks, and open woodland.
They may be found all over the state. Still, some good spots are Hitchcock Nature Area, Red Rock Reservoir, Hawkeye Wildlife Management Area, Deere Dike, and Saylorville Reservoir.
8. Rough-legged Hawk
- Scientific name – Buteo lagopus
- Lifespan – 2 years (average), 18 years (maximum recorded)
- Size – 18.5 to 20.5 in (47 to 52 cm)
- Weight – 25.2 to 49.4 oz (715 to 1400 g)
- Wingspan – 52 to 54.3 in (132 to 138 cm)
- Status – Least concern
The Rough-legged Hawk is a large, narrow-winged raptor. The body is well-patterned and dark brown. The base of the tail is white, while the tip is black. The wings are usually pale underneath, with black patches on the wrists.
The head is pale, and the belly is pale with a dark patch. Dark morphs occur, and they are dark brown all over with a pale trailing edge on the underwing. This species makes a mew-like call that sounds like a cat.
Rough-legged Hawks build bulky stick nests, which may include bones. The nest is lined with feathers, twigs, fur, sedges and grasses. The nest site is usually on a cliff edge, and a pair may reuse a nest the following year.
Occasionally, they may nest on artificial structures or in trees. The female lays up to seven pale blue or green-mottled eggs in a clutch. The incubation period is 31 to 37 days. Once the chicks hatch, it takes 31 to 45 days until they fledge for the first time.
In their wintering range, they mainly feed on voles, shrews and mice.
The Rough-legged Hawk is a fairly common species with a stable population of approximately 590,000 breeding individuals.
The size of populations changes regionally depending on food availability and harsh weather in their breeding range. Outside of the breeding territory, their biggest threat is car strikes when they feed on road kill.
Rough-legged Hawks are found in open areas such as prairies, semideserts, fields, dunes, bogs, marshes and shrubsteppes. In Iowa, they can only be seen during winter from October to April, after migrating south from Alaska and Canada.
They can be seen in many areas, including Hawkeye Wildlife Management Area, Red Rock Reservoir, Neal Smith National Wildlife Refuge, Saylorville Reservoir, and Ada Hayden Heritage Park.
9. Ferruginous Hawk
- Scientific name – Buteo regalis
- Lifespan – 12 years (average), 23 years (maximum recorded)
- Size – 22.1 to 27.2 in (56 to 69 cm)
- Weight – 34.5 to 73.2 oz (977 to 2074 g)
- Wingspan – 52.4 to 55.9 in (133 to 142 cm)
- Status – Least concern
The Ferruginous Hawk is a large, broad-winged raptor with a white belly and underwings, rusty patches underneath and rusty-coloured legs.
The back is chestnut, the tale is pail, and the primaries have white streaks. The dark morph is a dark, rufous-brown colour with white primary feather bases. The call made by this species is a scratchy scream that sounds like a gull call.
The Ferruginous Hawk nests on trees, cliffs, manufactured utility structures, boulders, shrubs and haystacks. The nest is often placed on remnant nests made by other species. The nest comprises twigs, sticks, plastic, metal pieces, bones or sagebrush.
The nest lining includes cow dung, bark or sod. The female lays as many as eight eggs per brood, and the creamy white eggs are incubated for 32 to 33 days. The hatchling period is 38-50 days, after which the chicks fledge.
Ferruginous Hawks feed on ground squirrels, hares, rabbits, prairie dogs and pocket gophers. Their diet is sometimes supplemented with birds, reptiles, amphibians and insects.
The Ferruginous Hawk population has increased by almost 1% per year for the past five decades, leading to an estimated population size of 110,000 breeding individuals. Regional population decreases may still occur because of agriculture, overgrazing, mining, fire, and pesticide use.
The Ferruginous Hawk occurs in open grasslands, shrublands and the edges of forests with surrounding open land. This hawk species is extremely rare in Iowa and has only been seen during winter from October to April.
There aren’t many locations to look for this species in the state, but they have been seen relatively frequently at Owego Wetland Complex and Hitchcock Nature Area. Other sites where they have been spotted in the past include Zirbel Slough, Big Marsh Wildlife Management Area, and Doolittle Prairie State Preserve.
10. Northern Harrier
- Scientific name – Circus hudsonius
- Lifespan – 8 years (average), 16 years (maximum recorded)
- Size – 18.1 to 19.7 in (46 to 50 cm)
- Weight – 10.6 to 26.5 oz (300 to 750 g)
- Wingspan – 40.2 to 46.5 in (102 to 118 cm)
- Status – Least concern
Northern Harriers are long, slender raptors with broad, long wings and a long tail. A significant amount of sexual dimorphism is seen in this species. The female is brown above and pale below with brown streaking.
On the other hand, the male is grey above and white below. Both genders have a pale white rump. The call produced by the Northern Harrier is a rapid series of kek notes.
Northern Harriers breed at ground level, making their nests amongst thick vegetation, including brushtails, grasses, reeds and willows. The nest is made from dense plants such as willows, alders and cattails. The nest is lined with sedges, grasses and rushes.
The female lays four or five white eggs in a clutch. The eggs are incubated for 28 to 36 days, and the hatchlings grow for 14 days after hatching, when they become ready to fly.
The Northern Harrier feeds on small mammals, birds, amphibians and reptiles. Specifically, they feed on deer mice, meadow voles, house mice, rabbits, shrews, meadowlarks, cardinals and sparrows.
Northern Harrier populations are steadily declining, although they are still reasonably common. They have decreased by around 34% since 1966, resulting in an estimated breeding population of 820,000 individuals.
The decrease is due primarily to a loss of habitat because of wetland draining and development for agriculture. Food availability has also decreased because their prey items have fallen victim to pesticides, overgrazing and reduced hiding places because of crop field growth.
The Northern Harrier is a migratory species that may be seen in the state commonly during winter, usually between September and May. They fly north to breed, and their numbers decrease in the state, but some remain all year round.
They are typically seen quartering over marshlands and grasslands. They also occur in undisturbed wetlands, upland prairies, old fields, meadows, shrubsteppe and riverside woodland habitats.
Some of the best places to see them in Iowa are Neal Smith National Wildlife Refuge, Ada Hayden Heritage Park, Hitchcock Nature Area, Dewey’s Pasture, and Cone Marsh Wildlife Management Area.
Iowa has a very well-represented range of hawk species that may be seen in different seasons. The different species have various reasons for visiting the state, from breeding purposes to escaping the cold weather further north during winter. Being in the state during migration can be very rewarding for hawk-watching in many locations.
Hawks have some of the best eyesight in the animal kingdom because of their ability to see ultraviolet light. That makes them incredible hunters and very successful survivors. They are, however, under threat from many factors.
They have faced many threats throughout history because of persecution, habitat destruction and indirect poisoning from pesticides such as DDT that are used to kill their prey items. Most of the species populations are now stable or increasing slightly due to advanced conservation and management practices that prevent illegal hunting in some areas and the formation of protected areas.
Hawks are often favourites amongst travelling birders, and seeing them soaring up in the sky never ceases to amaze a viewer.