Today, we embark on a journey to explore what North American Birds of Prey eat. While these raptors may share similar appearances, thee prey types they consume and preferences in their diets reveal remarkable distinctions. From the Bald Eagle to the stealthy Northern Goshawk, each species has honed its hunting strategies and behavior to target a specific type of prey. Join me as we uncover the diversity of food types in the diet of the diurnal birds of prey of North America.
North American Birds of Prey exhibit a diverse range of diets, with some species specializing in hunting birds, while others focus on mammals. Accipiter Hawks, such as the Sharp-shinned Hawk and Cooper’s Hawk, primarily consume birds, while the Northern Goshawk switches between birds and mammals depending on the season.
Buteo Hawks have a more varied diet, with proportions of mammals, birds, reptiles, amphibians, and invertebrates varying geographically and among years.
Falcons, known for their speed and agility, mainly prey on birds, while the American Kestrel targets large insects.
Vultures feed exclusively on carrion, snail-eating kites feed exclusively on snails, while the Osprey is a skilled fisherman that eats fish. Overall, the importance of birds or mammals in the diet of diurnal Birds of Prey depends on the specific species and their hunting strategies.
Accipiter Hawks
Accipiter Hawks are a group of quick and agile raptors found in boreal forests, mixed woodlands and scrub, and even backyard bird feeders throughout North American. They are known as “true hawks,” derived from the Latin word Accipiter.
These birds have evolved specific traits to capture other birds in dense woods and thick vegetation. They have short and rounded wings, which allows them to maneuver quickly and weave through heavy brush with ease.
Accipiter Hawks have rudderlike tails that aid in tracking the twisting and turning flight of their bird prey. They contribute to the ecological balance in their respective habitats and play an essential role in controlling bird populations.
Prey Selection and Diet of Accipiter hawks of North American
Accipiter hawks eat other birds and are the ultimate bird hunters. The three North American Accipiter hawks are well adapted to pursue and capture birds in thick foliage. Birds constitute the vast majority of the type of food they eat.
Sharp-shinned Hawk (Accipiter striatus): This is the most abundant and smallest species among the accipiters across its range.
Sharp-shinned Hawks specialize in very small birds. In parts of its range, this hawk follow migratory birds along their migration routes to breed in the same areas.
Cooper’s Hawk (Accipiter cooperii): The Cooper’s Hawk is the second most common and second largest accipiter hawk. This Accipiter is larger than the Sharp-shinned Hawk and prey upon larger birds such as starling, doves, and even ducks.
Due to its larger size, it also take mammals such as squirrels and small r rabbits.
Northern Goshawk (Accipiter gentilis): The Northern Goshawk is the least common Accipiter Hawk. It is mostly restricted to northern latitudes.
Northern Goshawks have a more flexible died. They feed on both birds and mammals throughout the year, but the proportions of these prey types vary with the seasons. During the breeding season, goshawks primarily consume birds, whereas in the nonbreeding season, mammals constitute the majority of their prey.
Approximate proportions of food types eaten by Accipiter Hawks.
| Mammals | Birds | Reptiles | Frogs & Amphibians | Insects – Invertebrates | |
|---|---|---|---|---|---|
| Sharp-shinned Hawk | 3.5% | 96.5% | |||
| Cooper’s Hawk | 8.7% | 91.3% | |||
| Northern Goshawk | 79(*) | 80%(*) |
(*) The Northern Goshawk switches its diet throughout the year. During the breeding season, it primarily consumes birds and the remaining portion consists of mammals. In the nonbreeding season, the majority of its prey consists of mammals, with the remainder being birds. Seasonal dietary shifts are partially influenced by bird abundance, particularly in relation to bird migration in northern latitudes.
Buteo Hawks of North American
The Buteo hawks of North America are a diverse group of medium-to-large hawks known for their exceptional soaring abilities. They are skilled at riding the winds and can soar for extended periods with their wings set. Unlike accipiters and falcons, which share common habitats and hunting methods, buteos exhibit great diversity among species and even within species.
Buteo Hawks have broad rounded wings and broad tails that are ideal for soaring and gliding over open spaces. They are relatively large which gives them power and strength, allowing them to take larger prey items.
Buteo hawks are equipped with keen eyesight, strong talons, and plumage patterns that allow them to blend into the environment. Their talons are well-adapted for capturing a variety of prey items.
In North America, Buteo Hawks include:
- Zone-tailed Hawks (Buteo albonotatus)
- Red-shouldered hawk (Buteo lineatus)
- Broad-winged Hawk (Buteo platypterus)
- Short-tailed Hawk (Buteo brachyurus)
- Swainson’s Hawk (Buteo swainsoni)
- White-tailed Hawk (Bueto albicaudatus)
- Red-tailed Hawk (Buteo jamaicensis)
- Ferruginous Hawk (Buteo regalis)
- Rough-legged Hawk (Buteo lagopus)
- Gray Hawk (Buteo nitidus)
Prey Selection, Types and Proportions
The diversity and adaptability of buteo hawks make them have the most diverse prey types in their diets. Percentage of prey types caught and consumed by Buteo Hawks varies geographically by habitat use, and often dramatically among years.
As an example, in part of their range, the diet of the Red-tailed hawk can be composed of 98% mammals. In other parts mammals, birds, reptiles and invertebrates are consumed in nearly similar proportions.
The following is an estimate of the average proportion of the type of food consumed by species within the group Buteo-hawks.
Across species, regions, and habitats, Buteo Hawks consume approximately 41% mammals, 27% birds, 12% reptiles, 10% amphibians (frogs), and 10% invertebrates.
The Gray Hawk of the extreme Southwest is less generalist than the other Buteo hawks. It occurs in riparian areas dominated by cottonwood with adjacent areas of mesquite. The Gray Hawk is a solitary hunter that has specialized on reptiles. Up to 68.6% of their diet is composed of reptiles, followed by 19.6% mammal, 9.8% bird, and 2% amphibians.
Hawks outside the Buteo Group
There are two North American hawks that do not belong to the Buteo genus; each belongs to a separate genus. These hawks are more specialized in their habitat and diet compared to the Buteo Hawks.
Common Black hawk (Buteogallus anthracinus): The Common Black Hawk occurs near the southwest border and it favors streams and the associated riverine or riparian forests. This hawk is a habitat specialist and food generalist.
The Common Black-Hawk eats just about anything that moves within the narrow habitat they favor. Their diets include 59% fish, 17.6% amphibians, 13.7% reptiles, 5.5% mammals, 2.2% invertebrates (caterpillar and other types of larvae), 1.9% birds.
Harris’s Hawk (Parabuteo unicinctus): The Harris’s Hawk occurs in semi-open desert scrub, savanna, grassland, and wetland habitats. They are cooperative hunters that have specialized on hunting rabbits, mice and other small mammals. Up to 91% of their diet is composed of mammals. The remaining 9% is composed of snakes, lizards, birds, and insects.
Falcons
Falcons are renowned as incredibly fast birds of prey and their name is synonymous with speed and agility. These blade-winged raptors are commonly found in open habitats such as arctic tundra, prairie sage, floodplains, tidal flats, open marshes, plowed fields, and barrier beaches. During migration, they can even be spotted in offshore waters.
Most Falcons are Aerial Hunters
Falcons are built as efficient predators, specializing in capturing prey in flight. Unlike Accipiter Hawks, which are skilled at maneuvering through dense vegetation, falcons prefer wide open spaces for their hunting strategies. They engage in one-on-one shootouts with their prey, utilizing their superior flying skills to secure a meal.
Prey Selection and Diet of North American Falcons
Falcons are specialized in capturing their prey mostly in the air. Hence, the main food type in their diet is birds. As with other birds of prey, percentages of birds consumed by falcons vary geographically, by habitat use, and often among years.
The following is an estimate of the average proportion of the types of food consumed by falcons.
Peregrine Falcon (Falco peregrinus): Studies on the diet of the Peregrine Falcon found that their diet is composed of 77% to 99% of birds. They may take small mammals and occasionally insects such as dragonflies.
Gyrfalcon (Falco rusticolus): Up to 95% of the food taken by the Gyrfalcon are birds. They have specialized on ptarmigan, grouse, and waterfowl. They can also take lemmings, voles and shrews.
Prairie Falcon (Falco mexicanus): The diet of prairie falcons vary dramatically according to region. They feed on mostly 95% of birds while in other regions mammals, particularly ground squirrels constitute nearly 100% of the prey types they take.
Merlin (Falco columbarius): Up to 90% of the food taken by merlins are small birds. The rest is composed of bats, dragonflies and small rodents.
Aplomado Falcon (Falco femoralis): The diet of the Aplomado Falcon is composed of mostly (93%) of birds. They also take bats and small rabbits.
This chart summarizes the diet of the Peregrine, Gyrfalcon, Prairie, Merlin, and Aplomado Falcons. IT show shows how specialized falcons are in hunting birds as their main food source. The falcons represented in this chart have special adaptations for high-speed flight and maneuverability. The fact that they are unable to catch other types of prey with ease makes their diets heavily skewed towards birds, which is easy to understand.
The following two species of North American falcons have very different hunting strategies and have a very different diet compared to the aerial hunting falcons.
American Kestrel (Falcon sparverius): The tiny American Kestrel is the smallest of all falcons. It uses mostly the sit-and-wait from vantage point strategy from where it pounce on mostly large insects. They can also hover to locate a prey on the ground. American Kestrels take mostly large insects (74%), followed by mammals (10%), birds (9%) and herps and reptiles (1%).
Crested Caracara (Polyborus plancus): The Crested Caracara stands as an unusual member of the Falcon family, foraging exclusively on the ground in open country. Its diet includes 24% reptiles, 23% fish, 13.4% birds, 7.4% frogs, and other amphibians. Caracaras also scavenge carrion when available.
Summary tables depicting the proportions of various prey types consumed by North American Falcons.
| Mammals | Birds | Reptiles | Frogs & Amphibians | Insects | |
|---|---|---|---|---|---|
| Peregrine Falcon | 77% – 99% | ||||
| Gyrfalcon | 95% | 5% | |||
| Prairie Falcon | 100% (*) | 95% | |||
| Merlin | 5% (bats, rodents) | 90% | 5% (dragonflies) | ||
| Aplomado Falcon | 7% (bats & rabbits) | 93% | |||
| American Kestrel | 10% | 9% | 0.5% | 0.5% | 74% |
Summary table depicting the proportions of various prey types consumed by the Crested Caracara.
| Mammals | Birds | Reptiles | Frogs & Amphibians | Fish | |
|---|---|---|---|---|---|
| Crested Caracara | (*) | 7.4% | 24% | 7.4% | 13.4% |
North American Kites
The term “kite” refers to a small, insect-eating raptor. Kites swoop on their prey in mid air.
Some associate the word “kite” to describe a behavior of hanging (hovering) motionless in the air; a behavior often performed by American Kestrels and Red-tailed Hawks.
North American kites can be divided into two distinctive groups. Although they share the same name, they have distinct diets and hunting behaviors. One group consists of snail-eating kites, and the other comprises aerial foragers.
Snail-eating Kites
Snail-eating Kites are resident birds with highly specialized beaks geared to dislodge snails from their shells. They search for snails from branches or the air and often transport them to a perch for manipulation and consumption.
Prey Selection and Diet of North American Snail-eating Kites
Snail Kite (Rosthramus sociabilis): The snail kite is the ultimate snail specialist with a diet composed of nearly exclusively aquatic apple snails.
Hook-billed Kite (Chondrohierax uncinatus). The Hook-billed Kites is not specialized on only one type of snail but consumes land snails of many types. They also include lizards and invertebrates.
| Mammals | Birds | Reptiles | Frogs & Amphibians | Insects – Invertebrates | |
|---|---|---|---|---|---|
| Snail Kite | 0.5% (baby turtles) | 99% (apple snails) 0.5% (insect larvae) | |||
| Hook-billed Kite | 0.5% (lizards) | 99% (snails), 0.5% (grasshoppers, centipedes) |
Prey Selection and Diet of North American Aerial Foraging Kites
Aerial foraging kites are masters of the sky. They often spend most of the day gliding, soaring, hovering, and performing maneuvers through trees and land contours. They have long pointed wings, slender bodies and long tails that enables them to perform such graceful flight.
| Mammals | Birds | Reptiles | Frogs & Amphibians | Insects – Invertebrates | |
|---|---|---|---|---|---|
| Swallow-tailed Kite | 33% (nestlings) | 3% (lizards) | 33% (mostly frogs) | 30% (insects) | |
| Mississippi Kite | 1% | 3% | 3% | 3% | 80% |
| White-tailed Kite | 95% (mice, voles) | 1% | 1% | 2% | 1% |
Northern Harrier
The Northern Harrier (Circus hudsonius) is a slim and graceful raptor that represents the only species of its genus in North America. The Norther Harrier favors open habitats where it is often seen cruising low to the contour of the land rocking its body from side to side interspersed with sudden drops to the ground swoop of prey.
Northern Harriers use their keen eyesight specialized hearing aided by the facial disks on this raptor’s face.
Prey Selection and Diet of the Northern Harrier
The Northern Harrier excels in the subtle art of sneaking up from behind to catch its prey. It favors marshy meadows, wet pastures, freshwater and brackish marshes, upland prairies, mesic grasslands, old fields, and riparian woodland.
Its hunting strategy involves a low, cruising flight with pull-ups, wing-overs, and drop-pounces, perfectly suited for capturing small creatures like meadow voles, mice and small birds.
The approximate average food type approximated from multiple studies include:
| Mammals | Birds | Reptiles | Frogs & Amphibians | Insects – Invertebrates | |
|---|---|---|---|---|---|
| Northern Harrier | 90% | 4% | 2% | 2% | 2% |
North American Vultures
North American vultures are remarkable birds that excel in two disciplines: soaring and sanitation. Vultures play a vital role in the ecosystem as carrion feeders, helping to keep the environment clean. North American Vultures include.
- Black Vulture (Coragyps atratus)
- Turkey Vulture (Cathartes aura)
Both vultures possess unfeathered heads, a characteristic they share with the endangered California Condor. This adaptation aids them when feeding on carrion, as a naked head avoids accumulating gore compared to a well-feathered one.
Prey Selection and Diet of the Northern Harrier Vultures
Black and Turkey vultures’ mastery of soaring is unparalleled, and they can effortlessly ride the wind to find carrion even when other soaring birds are grounded. Vultures feed exclusively on carrion.
If the opportunity presents itself, vultures can take incapacitated small reptiles and birds, eggs, and larvae.
The approximate average food type approximated from multiple studies include:
| Carrion | Birds | Reptiles | Frogs & Amphibians | Insects – Invertebrates | |
|---|---|---|---|---|---|
| Black Vulture | 99% | 0.25% | 0.25% | 0.25% | 0.25% |
| Turkey Vulture | 99% | 0.25% | 0.25% | 0.25% | 0.25% |
Eagles
Among North America’s native eagles, the Bald and Golden eagles are the largest true birds of prey. The Bald Eagle is more widespread and can be found throughout the continent associated with coastal areas, large inland lakes, and rivers. Despite being primarily known for their fish-eating habits, the bald eagle is an impressive hunter.
Snail eating kites are specialized in snails. No other North American bird is equipped with a highly specialized beak that enables them to dislodge snails from their shells.
Golden eagles have a more in-land distribution. They inhabit a wide range of environments, spanning from the tundra to grasslands, intermittent forested areas, and woodland-brushlands. They can also be found in the southern regions, including arid deserts and canyonlands.
Prey Selection and Diet of North American Eagles
The Bald Eagle is a versatile hunter, foraging on fish, waterfowl, and other prey. Bald Eagles are more opportunistic and often gather in areas where dead or dying fish is likely to occur.
Perch-hunting is a common practice for Bald Eagles, and their relative inactivity demonstrates their ability to locate and capture food when needed.
The Golden and Bald Eagle have dissimilar food habits. The Golden Eagle employs active search-and-soar tactics while hunting. It also uses perch-hunting from where it scans their surroundings in search of prey to pounce.
The approximate average food type approximated from multiple studies include:
| Mammals | Birds | Fish | Reptiles, & Amphibians | Carrion | |
|---|---|---|---|---|---|
| Bald Eagle | 14% | 28% | 56% (*) | 1% | 1% |
| Golden Eagle | 84% | 15% | 0.3% | 0.3% | 0.3% |
Osprey
Ospreys (Pandion heliaetus) are found across much of the globe, primarily in the Northern Hemisphere. In continental North America, Ospreys range from coastal Alaska to Newfoundland, avoiding arid and treeless regions.
The Osprey is a large raptor with a unique evolutionary specialty – diving for fish. Unlike other birds of prey, Ospreys dive talons-first into the water, often immersing themselves completely in pursuit of fish near the water surface.
Prey Selection and Diet of the Osprey
The Osprey exhibits fisherman-like patience while hovering over the water until it spots its prey. It folds up its wings and dives head-first, adjusting the angle to account for refraction, and catches its prey with a net of talons just before hitting the water. While fish is the primary prey, Ospreys may occasionally catch snakes or muskrats.
More than half the time, the Osprey emerges with its catch, which it carries off to a perch to feed.
| Mammals | Fish | Reptiles | Frogs & Amphibians | Insects – Invertebrates | |
|---|---|---|---|---|---|
| Osprey | (*) | 100% | (*) | (*) |
Conclusions
North American Birds of Prey eat mostly mammals and birds. Reptiles and invertebrates are consumed with less frequency. Each species has evolved to master the art of hunting specific prey types, showcasing their remarkable adaptability and resourcefulness. From the Snail-eating Kites, delicately extracting snails from their shells, to the powerful Golden Eagles, swooping down to catch their avian or mammalian prey, their predatory prowess is remarkable.
References:
- Birds of the World (2022). Edited by S. M. Billerman, B. K. Keeney, P. G. Rodewald, and T. S. Schulenberg. Cornell Laboratory of Ornithology, Ithaca, NY, USA. https://birdsoftheworld.org/bow/home
- Del Hoyo, J., A. Elliott, J. Sargatal. 1994. Handbook of the birds of the World. Vol 2 New World Vultures to Guineafowl. Barcelona: Lynx Edicions.
- Falcons and Caracaras (Falconidae). 2002. M Hutchins, J Jackson, W Bock, eds. Grzimek’s Animal Life Encyclopedia, Vol. 8, Second Edition. Detroit: Gale Group.
- Griffiths, C. 1999. Phylogeny of the Falconidae inferred from molecular and morphological data. The Auk, 116: 116-130.
- Kemp, A., I. Newton. 2003. Hawks, Eagles and Old World Vultures. Pp. 162-175 in C Perrins, ed. The New Encyclopedia of Birds. Oxford: Oxford University Press.
- Thiollay, J. 1994. Family Accipitridae (hawks and eagles). Pp. 52-105 in J del Hoyo, A Elliott, J Sargatal, eds. Handbook of the Birds of the World. Vol. 2. New World Vultures to Guineafowl. Barcelona: Lynx Edicions.