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16 Largest Birds In Illinois (Size Comparison+Photos)

Living in Illinois and saw some big birds but are not sure which ones they were?

Illinois is known for its avifauna. According to the Illinois Ornithological Records Committee (IORC), there are over 450 species of birds there! And just like in Florida, Michigan, Ohio, Colorado, Pennsylvania, and Texas, plenty of those can grow up to impressive sizes.

Examples of large birds in Illinois include the black vulture, snowy owl, great horned owl, Canada goose, golden eagle, bald eagle, sandhill crane, and many others. 

The largest bird in Illinois is the trumpeter swan with a wingspan of up to 98 inches, a length of almost 71 inches, and a weight of up to 30 pounds.

Some of these giant birds, like the great horned owl and black vulture, can be seen year-round in the state, while others, like the snowy owl and golden eagle, will spend only winter there. 

Here are their photos, sizes, and fun facts – from the smallest to the largest bird.

Large Birds In Illinois

1. Pileated Woodpecker

pileated woodpecker

Scientific name: Dryocopus pileatus 
Lifespan: 12 years
Length: 16-19 in
Wingspan: 26-30 in
Weight: 7.9-14.1 oz
Range In Illinois: Year-round resident in Southern Illinois

Pileated woodpeckers are the largest woodpeckers found in Illinois. They are permanent and statewide residents there and can be found in bottomland forests and woodlots.

The word “pileated” comes from the Latin word “pileatus” which means “capped” – pileated woodpeckers are primarily black with a prominent red crest on their heads.  They also have white lines on their throats and white on their wings. Males are also with red lines on the side of their heads; this is absent in females. 

Look for them hitting dead trees in pursuit of ants and making rectangular holes in the process. These black and red woodpeckers are omnivores that feed on insects (especially carpenter ants), fruits, nuts, and berries. 

They are rare around bird feeders; the only way they visit them is if the winter is extremely cold. Try to attract pileated woodpeckers to your backyard by adding suet to your feeders, leaving dead trees for them to forage or roost there, or putting up a nest box to attract a breeding pair. 

Pileated woodpeckers are crucial for making tree holes that other bird and animal species use to nest. Their nesting season in Illinois lasts from April to May and females lay 4 white eggs.

Fun Fact: The famous cartoon character, Woody Woodpecker, is said to have been based on pileated woodpeckers.

2. Double-crested Cormorant

long eyebrows of a double crested cormorant

Scientific name: Phalacrocorax auritus
Lifespan: 6-17 years
Length: 28-35 in
Wingspan: 45-48 in
Weight: 2.6-5.5 lb
Range In Illinois: Winter resident in Southern Illinois

Double-crested cormorants are the largest cormorants found in Illinois. These large black water birds measure from 28 to 35 inches in length and can reach 5.5 pounds!

Most populations just migrate through the state, but there are double-crested cormorants that can be seen in Illinois during summer (northern parts) and winter (southern parts), usually around lakes, rivers, or swamps. 

They are the most widespread cormorant species in North America and can be recognized by their jet-black plumage, small heads, long necks, and thin, strongly hooked orange beaks

Identify them also by their most common call which is a deep guttural grunt that resembles a pig oinking. When the breeding season starts, males will also develop bushy white eyebrows (feathery tufts). 

These birds are excellent swimmers that can dive over 24 feet and stay there for over a minute. However, since they do not have fully waterproof feathers, after hunting, they will need to stand on the shore with their wings spread to dry. 

Double-crested cormorants are carnivores that feed on fish, and occasionally amphibians and crustaceans. The oldest documented wild double-crested cormorant lived to be almost 18 years old!

3. Swainson’s Hawk

Swainson's Hawk

Scientific nameButeo swainsoni 
Lifespan: Up to 26 years
Length: 17–22 in
Wingspan: 46–54 in 
Weight: 1.1–3.7 lb 
Range In Illinois: Summer resident in Northern Illinois

Swainson’s hawks are one of the largest hawks of Illinois. These giant raptors were named after a British naturalist William Swainson. 

People also call them grasshopper hawks or locust hawks due to them eating large amounts of locusts and grasshoppers. They breed in grasslands of the midwestern and Western USA; in Illinois, Swainson’s hawks are summer residents in the northern half of the state and can be seen there from late March to late September. 

While flying, they love to soar in circles and will winter in South America. These hawks will cross 6,000 miles when migrating – this makes them one of the longest-distance migratory raptors in the world. 

Identify Swainson’s hawks by their pale to brown plumage, dark bands on their breasts, hooked beaks, and whistled “kreer” calls. According to the Illinois Department of Natural Resources, Swainson’s hawks are considered endangered in Illinois.

4. Rough-legged Hawk

Rough-legged Hawk

Scientific name: Buteo lagopus 
Lifespan: 15 years
Length: 18-24 in
Wingspan: 47-60 in
Weight: 1.3-3.6 lb
Range In Illinois: Winter resident throughout Illinois

Rough-legged hawks or rough-legged buzzards are large birds of prey found in Europe, Asia, and North America. Females are bigger than males and weigh from 2.3 to 3.6 pounds; males are 1.3 to 2.2 pounds heavy. 

In Illinois, they are winter residents throughout the state, although they are seen more often in northern parts. During their non-breeding season, these long-winged raptors are common around marshes, fields, and open plains.

Rough-legged hawks come in different morphs. Light morphs have pale plumage with dark bellies and dark “wrist” patches while dark ones are brown-black with white flight feathers.

They were named after their feathered legs that help keep them warm in the Arctic regions. 

They also love to hover by beating their wings quickly, just like kestrels, osprey, and kites. Rough-legged buzzards have small talons which explains why they mostly hunt small mammals.

They have an interesting adaptation for locating their prey – rough-legged hawks have UV vision

Some small mammals, like voles and mice, leave trails of urine as they move. Those urine trails reflect ultraviolet light – rough-legged hawks see them glowing bright yellow which helps them locate their next meal and highlight hunting areas with high prey densities.

They nest in trees and cliffs, lay 1-7 bluish-white eggs with brownish spots, and males feed the females as they incubate the eggs – the species are monogamous. 

5. Great Horned Owl

great horned owl

Scientific name: Bubo virginianus
Lifespan: 15-25 years
Length: 17-25 in
Wingspan: 35.8-60.2 in
Weight: 2.7-3.5 lb
Range In Illinois: Year-round resident throughout Illinois

Also known as the tiger owl, the great horned owl is the second largest owl in Illinois. It is also among the largest owls in North America and lives in mountains, grasslands, conifer forests, deserts, chaparrals, and many other habitats. 

The great horned owl has the most diverse diet of all North American raptors. An aggressive and excellent hunter, this big bird feeds on rabbits, hares, rats, mice, voles, other small mammals, larger mid-sized mammals, reptiles, amphibians, and invertebrates.

It might occasionally even attack larger prey, including raptors such as ospreys, Peregrine falcons, prairie falcons, and other owls. It hunts using its acute hearing and excellent eyesight and can fly in near silence to catch its prey by surprise. 

In case you see a great horned owl in person, you will notice long, earlike tufts, intimidating yellow eyes, and a deep hooting call. It has a gray-brown plumage with a mottled pattern and a white patch at the throat. 

This large night owl is monogamous and pairs may stay together for over five years, sometimes even for a lifetime.

6. American Hering Gull

herring gull

Scientific name: Larus argentatus
Lifespan: up to 50 years
Length: 24-26 in
Wingspan: 47-61 in
Weight: 2.31–3.64 lb
Range In Illinois: Winter resident in Northern and Southern Illinois

Herring gulls are common gulls found in Illinois, one of the largest there. Their population in the state increases during winter, especially around Lake Michigan and other larger bodies of water.

Identify these large birds by their sloping foreheads, full chests, and long and powerful beaks. Adults are light gray with dark wingtips, white irises, and pink legs. Notice their massive beaks with a red spot on the lower mandible.

These birds are omnivores, primarily scavengers (like other gulls). They feed on invertebrates, fish, insects, carrion, and human refuse. Herring gulls are intelligent birds that can be often seen dropping clams and mussels from a height on hard surfaces to open them.

They nest on rocky cliffs and are one of many white birds found in Hawaii.

7. Black Vulture

black vulture

Scientific name: Coragyps atratus
Lifespan: 10 years in the wild
Length: 22–29 in
Wingspan: 52-66 in
Weight: 3.5-6.6 lb
Range In Illinois: Year-round resident in Southern Illinois

Black vultures are aggressive large birds of prey that have black plumage, naked black heads, chalky white feet and legs, and white wing patches that can be seen during flight. Both sexes look similar. 

Black vultures are year-round residents in southern Illinois and their population has increased in those parts of the state in recent years. 

People often mistake them for turkey vultures; the main difference is the bigger size and wider wings and tails in turkey vultures. In addition, black vultures flap their wings more frequently when flying. 

Black vultures are highly gregarious birds and might form large communal roosts at night that can often include turkey vultures. They are carnivores and primarily feed on carrion; black vultures may also hunt and eat small reptiles, birds, and mammals. They will spend most of their day looking for food. 

To escape from danger, these large black birds will regurgitate partially digested food to distract the attacker and become lighter before flying away. Black vultures are monogamous and pairs are believed to mate for life – both the male and female will take turns incubating their eggs. 

Black vultures are protected under the Migratory Bird Treaty Act and you can’t kill them without a permit.

8. Snowy Owl

snowy owl

Scientific name: Bubo scandiacus
Lifespan: 10 years in the wild
Length: 21-28 in
Wingspan: 45.7-72 in
Weight: 2.9-6.5 lb
Range In Illinois: Winter resident in Northern Illinois

Snowy owls are giant white birds of prey. They are the heaviest owls in Illinois and have a longer wingspan than any other owl found there. 

Because of the cold weather in the Arctic regions they inhabit, snowy owls need good insulation; that is why their feet are covered with feathers! This resulted in them being one of the heaviest owls in the world, reaching up to 6.5 pounds.

Females are larger than males and span up to 6 feet across the wings. They are the only white owls in the world and males tend to be whiter than females; both have some black or brown markings on the body and wings and yellow eyes. 

Snowy owls are native to the Arctic region of North America and breed on the tundra. Snowy owls will occasionally winter in Illinois, mostly in the northern parts of the state. They are common around prairies, fields, marshes, lake edges, airports, golf courses, and urban areas where they are most active during the day.

They are very vocal birds with over 15 different calls. The most common call consists of 2-6 rough notes that sound like “krooh-krooh” and can be heard for miles. They might also make some rattle “rick-rick-ha-how-quock” calls. 

Snowy owls are diurnal birds that sleep during the night and hunt during the day, especially when the summer comes; their diet includes small mammals, some water birds, fish, and even carrion.  Their favorite food is lemmings (small mouselike rodents) – they might hunt as much as 1,600 of those per year. 

Snowy owls are monogamous and mate for life. A female will lay 3-11 eggs in the nest on the ground. The male will feed her while she incubates the eggs for around a month.

9. Turkey Vulture

turkey vulture

Scientific name: Cathartes aura 
Lifespan: 16 years 
Length: 63-72 in
Wingspan: 24-32 in 
Weight: 1.8-5.3 lb
Range In Illinois: Summer resident throughout Illinois

Turkey vultures are huge black birds and the most widespread of the New World vultures. Also known as turkey buzzards or just buzzards, they were named after their resemblance to wild turkeys. 

With a wingspan of around 6 feet, black-brown plumage, bare red heads, and white legs, turkey vultures are hard to miss in the sky. Look for their silvery flight feathers that are contrasted with dark wing linings while they fly. They are one of the largest raptors in the USA, just after the eagles and condors. 

Turkey vultures are summer residents and occasional winter residents in the southern two-thirds of Illinois.

Using their keen vision and sharp sense of smell, turkey vultures can locate carrion easily. They lack a syrinx (the vocal organ) which makes them voiceless; all turkey vultures can do is hiss, whine, and grunt. 

They are very social birds that roost in large community groups with several hundred individuals. You might also spot them sitting in trees on the sides of roads waiting for their next meal. 

They do a great service across the US by removing dead animals and preventing the transmission of any diseases those dead animals could have carried. Because of their extremely strong stomach acids, turkey vultures can eat and digest carcasses tainted with anthrax, tuberculosis, and rabies, without getting sick.

10. Canada Goose

canada goose

Scientific name: Branta canadensis
Lifespan: 10-24 years 
Length: 30-43 in
Wingspan: 50-73 in 
Weight: 5.7–14.3 lb
Range In Illinois: Year-round resident throughout Illinois

With a 6 ft wingspan, 3.5 ft length, and weight of over 14 pounds, they are the largest goose species found in Illinois. There are 7 subspecies of Canada geese – the largest of them, the giant Canada goose (B. c. maxima), is the only one that breeds in the state.

These ridiculously large birds are commonly found around wetlands, parks, fields, and golf courses; you will identify Canada geese by their brown color above that is paler below, black necks and heads, white cheeks, and black bills and legs. 

Canada geese are considered a nuisance in the state for eating field crops, feeding upon golf course greens and lawns, attacking people to defend their nests, or leaving droppings on lawns, athletic fields, and parks.

Canada geese mostly breed between February and April and have a clutch size of 4 to 10 eggs that females incubate. They are also known for flying in a distinctive V-formation and series of loud “honk” calls.

11. Sandhill Crane

sandhill crane

Scientific name: Grus canadensis 
Lifespan: 20 years
Length: 47.2 in
Wingspan: 78.7 in 
Weight: 6-14.8 lb
Range In Illinois: Breeding resident in Northern Illinois

Sandhill cranes are one of the most striking birds in Illinois. They measure almost 4 feet in height, span almost 7 feet across the wings, and weigh almost 15 pounds.

You will recognize them by their mostly slate gray plumage, rusty washes on the upperparts, pale cheeks in adults, red patches on their heads, and black legs. These extremely tall birds also have long necks and legs, and very broad wings. 

Sandhill cranes are summer residents in Northern Illinois, usually found around fields, prairies, the edges of swampy areas, lakes, and marshes.

These migratory birds start arriving around late February and after breeding, move south from late September to late November. Sandhill cranes are fairly social birds and can be usually found in pairs or family groups throughout the year. 

They are also monogamous and mate for life, staying together for years, until one of the cranes dies. Sandhill cranes mostly feed on plants, insects, and snails.

12. Great Blue Heron

a great blue heron with orange beak

Scientific name: Ardea herodias 
Lifespan: 15 years 
Length: 36–54 in
Wingspan: 66–79 in 
Weight: 4-7.9 lb
Range In Illinois: Year-round resident throughout Illinois

Great blue herons are one of the largest blue birds of the world

They are also the largest herons native to North America and can be found year-round throughout Illinois. Blue herons mostly inhabit marshes, ponds, lakes, flooded fields, swamps, and river shorelines.

With a wingspan of up to 6.6 ft, these blue-winged birds are hard not to see. Great blue herons are blue-gray and have large yellow-orange beaks, short black plumes on their heads, and black and chestnut patterns on the shoulders. During the flight, they will hold their neck in an S-shape with legs trailing behind. 

Great blue herons are monogamous only for a single season and will go through some interesting courtship rituals, locking and rubbing their bills on the feathers of the other bird before mating.  Both parents will take turns in incubating the eggs. They nest in colonies called heronries that can occasionally have more than 500 nests!

Great blue herons are carnivores that feed on fish, amphibians, reptiles, invertebrates, small mammals, and even other birds. These wading birds will slowly stalk their prey in shallow waters, striking with lightning speed, and catching them with their long and sharp beaks.

13. Golden Eagle

golden eagle

Scientific name: Aquila chrysaetos
Lifespan: up to 30 years
Length: 26-40 in
Wingspan: 70.8-90.1 in
Weight: 7.9-11 lb
Range In Illinois: Winter resident throughout Illinois

Golden eagles are one of Illinois’ largest eagle species. They measure from 30 to 40 inches in length and can weigh as much as 11 pounds.

These enormous birds are also one of the fastest and most agile birds of prey in the USA. Identify golden eagles by their overall dark brown plumage and the lighter golden-brown color of their napes. Their agility and speed together with powerful feet and large, sharp talons allow golden eagles to hunt rabbits, hares, and ground squirrels. 

Although seen in most of Illinois during winter, golden are most common along the Mississippi River and at wildlife refuges in southern Illinois. They start arriving in the state around late October and leave in March.

These raptors will catch rising masses of warm air to soar in the air with very little effort and look for their next meal – when they spot their prey, these brown-colored eagles will swoop at 200 mph. They are common around lakes, ponds, reservoirs, rivers, and streams.

Golden eagles are monogamous and mate for life. They are very territorial and will often attack hawks, eagles, and falcons that enter their territory. They construct huge nests that can be 5-6 feet wide and 2 feet high – the largest ever recorded golden eagle nest was 20 feet tall and 8.5 feet wide!

14. Bald Eagle

Bald Eagle With a Beak

Scientific name: Haliaeetus leucocephalus
Lifespan: 20-30 years in the wild
Length: 28-40 in
Wingspan: 70.8-90.5 in 
Weight: 6.6-13.9 lb
Range In Illinois: Winter resident throughout Illinois

Bald eagles are the largest eagle species found in Illinois. They range from 28 to 40 inches long and have a wingspan of up to 7 feet 7 inches.

These large raptors were selected in 1782 to be the national symbol of the United States and can be identified by their brown bodies, white heads and tails, and yellow legs and beaks. Before attaining these characteristics around the age of five, bald eagles are mostly dark brown with varying amounts of white mottling. 

With a growing eagle population, Illinois is a great place to see over 3,000 bald eagles in at least 27 counties during winter. These magnificent raptors can be first spotted in the state around December and stay there until March; they are most common along rivers or near lakes with large trees. 

Bald eagles build one of the largest nests of any North American bird – the largest recorded one was in Florida and measured 10 feet wide and 20 feet deep. 

These magnificent raptors are hard to miss as they soar through the air with their 7.5-foot-wide wingspan. Bald eagles are carnivores and opportunistic feeders that primarily consume fish they snatch from the water with their sharp talons.

Want to have a good laugh? Here are some photoshopped examples of birds (including bald eagles) without beaks.

15. Mute Swan

mute swan

Scientific name: Cygnus olor
Lifespan: up to 10 years in the wild 
Length: 49-67 in
Wingspan: 79-94 in 
Weight: 18.7-26.2 lb
Range In Illinois: Year-round resident throughout Illinois

Mute swans are the second largest birds in Illinois. They measure up to 5 ft 7 in long, span 7 ft 10 in across the wings, and weigh up to 32 pounds.

These large swan species were introduced to Illinois in 1971 and were named “mute” for being less vocal than other swan species. Regardless, they still produce a variety of hisses and other sounds. 

Identify mute swans by their all-white plumage, orange beaks with black borders, and pronounced knobs on top of their beaks. While swimming, mute swans will keep their necks curved and wings raised; when resting, the necks are curved like a letter S and the beaks are pointed downwards. 

Mute swans are permanent residents found throughout Illinois. They are common around ponds and lakes where they feed on submerged aquatic vegetation, crustaceans (crayfish, shrimp), fish, and aquatic insects.

These aggressive, territorial, and invasive swans that are not native to Illinois will fight with native trumpeter swans, pushing them out of their nesting area. 

Due to their large numbers and negative effect on other waterfowl and vegetation, they are now considered invasive species. Mute swans are monogamous and males will also incubate the eggs. Male swans are called “cobs”, females “pens”, and young are “cygnets”.

16. Trumpeter Swan

trumpeter swan

Scientific name: Cygnus buccinator
Lifespan: up to 25 years
Length: 54.3-70.8 in
Wingspan: 72.8-98 in 
Weight: 15–30 lb
Range In Illinois: Winter resident in Southern Illinois

Trumpeter swans are the largest birds native to Illinois. They have a wingspan of up to 98 inches, a length of almost 71 inches, and a weight of up to 30 pounds!

Trumpeter swans have been exterminated from Illinois by the late 19th century, but have been recovering in recent years. Thanks to the Endangered Species Act and strong reintroduction efforts, these swans are once again increasing in numbers and recolonizing their historic breeding range.

You will best identify trumpet swans by their white plumage and black bills. They are big, North America’s heaviest flying birds. Trumpeter swans are loud and their calls sound similar to a trumpet, which resulted in the specie’s name. 

They are mostly vegetarians and mainly eat plants found in or near the water. Occasionally they will eat insects, small fish, and eggs, but trumpet swans prefer plants overall.

Summary

This concludes our list of big birds in Illinois. There are plenty of eagles, swans, owls, and herons that grow to immense sizes and that can be found in the state. We hope you found this article interesting.

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