Illinois’s wetlands and waterways are home to a remarkable variety of herons, making it a prime location for bird watchers and nature enthusiasts.
At least 10 different types of herons can be found across the state, including the widespread Black-crowned Night-Heron and the majestic Great Blue Heron.
These elegant wading birds bring a touch of wild grace to the marshes, lakes, and rivers throughout Illinois.
These fascinating birds play important roles in local ecosystems and display striking differences in appearance, behavior, and habitat preferences.
Some, like the Black-crowned Night-Heron, are primarily nocturnal hunters, while others feed during daylight hours.
Illinois provides critical breeding grounds for many heron species, with rookeries established in protected wetlands where these birds build their nests and raise their young each breeding season.
The distinctive plumage of Illinois herons ranges from the yellow crown of the Yellow-crowned Night-Heron to the snowy white feathers of egrets.
Conservation efforts have helped protect these elegant birds, which were once hunted extensively for their decorative plumes.
Today, ornithologists and bird enthusiasts monitor heron populations across Illinois wetlands, recognizing them as important indicators of ecosystem health.
1. Great Blue Heron
The Great Blue Heron (Ardea herodias) is the largest heron found in Illinois. This impressive wading bird stands about 4 feet tall with a wingspan that can reach 6 feet across.
With its distinctive blue-gray plumage, the Great Blue Heron is easy to identify.
It has a white face with black plumes extending from behind its eyes. The bird also displays black and chestnut patterns on its shoulders.
Both male and female herons look similar, featuring long, skinny yellow-green legs and large yellow-orange bills.
These physical traits help them wade through water and catch prey efficiently.
Habitat & Behavior:
- Freshwater and saltwater wetlands
- Slow-moving rivers and streams
- Lake shores and pond edges
- Farm fields (when hunting for rodents)
Great Blue Herons are patient hunters. They often stand motionless in shallow water, scanning for prey before striking with lightning speed.
Their diet consists mainly of fish, but they also eat frogs, insects, rodents, and other small animals.
During breeding season, these herons build large stick nests in tall trees, typically in colonies called rookeries. They lay 3-7 pale blue eggs per clutch.
In Illinois, Great Blue Herons can be spotted year-round in suitable habitats.
Some individuals migrate south during harsh winters, while others remain if open water is available for feeding.
2. Great Egret
The Great Egret (Ardea alba) is a striking white heron found in Illinois.
This elegant bird is completely white with black legs, making it easy to identify even from a distance.
Equal in size to the Great Blue Heron, the Great Egret stands out with its impressive stature.
It features a long, slender neck and a yellow bill that turns orange-black during breeding season.
These birds are known for their graceful movements as they wade through shallow waters hunting for prey.
They primarily feed on fish, frogs, and other small aquatic animals.
The scientific name Ardea alba comes from Latin, with “Ardea” meaning heron and “alba” meaning white.
This large, lanky wading bird is also sometimes called the common egret, large egret, or great white heron.
In Illinois, Great Egrets can be found near wetlands, marshes, ponds, and lake edges.
They are more common during spring and summer months when they establish nesting colonies in tall trees.
Great Egret Quick Facts:
- Size: Large (similar to Great Blue Heron)
- Color: All white with black legs
- Bill: Yellow (orange-black during breeding)
- Habitat: Wetlands, marshes, ponds
- Diet: Fish, amphibians, small reptiles
Great Egrets were once threatened due to hunting for their beautiful plumes used in the fashion industry.
Today, they are widely distributed and fairly common throughout Illinois, thanks to conservation efforts.
The Illinois Department of Natural Resources identifies the Great Egret as one of several notable wading birds in the state, alongside other species such as the Great Blue Heron and Little Blue Heron.
3. Snowy Egret
The Snowy Egret (Egretta thula) is a striking white heron with distinctive features that make it easy to identify.
This medium-sized bird has pure white feathers that create a beautiful contrast against its black bill and black legs.
One of its most recognizable features is its bright yellow feet, which stand out dramatically against its dark legs.
During breeding season, the Snowy Egret becomes even more distinctive.
The area between its eye and bill (called lores) is usually bright yellow but flushes reddish during breeding.
They also develop elegant plumes on their heads, necks, and backs that they display during courtship.
In Illinois, these elegant birds are not commonly seen throughout the state.
They are considered a rare migrant through Illinois and only become summer residents in the southwestern part of the state along the Mississippi River.
Snowy Egrets have a distinctive hunting style. They are active feeders that run through shallow water with their wings partially spread, stirring up small aquatic prey.
Their diet primarily consists of:
- Small fish
- Crustaceans
- Insects
- Amphibians
The scientific name Egretta thula comes from Provençal French for the little egret “aigrette,” which is a diminutive of “aigron”.
These elegant birds are part of the heron family and contribute to the diverse wetland ecosystems where they live.
4. Little Blue Heron
The Little Blue Heron (Egretta caerulea) is about 24 inches long and displays striking plumage that changes with age.
Adult birds have a distinctive appearance with dark blue-gray feathers covering most of their body and rich purple-maroon coloration on the head and neck.
Young Little Blue Herons look completely different from adults.
Immature birds are actually white, often causing confusion with other heron species.
This unique color change helps birdwatchers identify this species in the field.
The adult’s bill is slate-colored with a darker tip, providing another identifying feature.
Their legs are greenish in breeding season and darker at other times.
Little Blue Herons tend to be wary birds that are difficult to approach in the wild.
They prefer shallow wetlands, marshes, and pond edges where they hunt for small fish, amphibians, and aquatic insects.
These herons have interesting nesting behaviors. They nest in colonies, sometimes forming single-species groups.
When part of larger mixed heron colonies, Little Blues typically establish nests along the outer edges.
In Illinois, Little Blue Herons are less common than Great Blue Herons or Great Egrets.
Birdwatchers should look for them in the southern and central parts of the state, particularly during spring and summer months.
Identifying characteristics at a glance:
- Size: Medium (about 24 inches)
- Adult coloration: Blue-gray body with purple-maroon head/neck
- Immature coloration: All white
- Habitat: Shallow wetlands and marshes
5. Tricolored Heron
The Tricolored Heron (Egretta tricolor) is a sleek and slender heron with distinctive coloration.
It showcases a beautiful mix of blue-gray, lavender, and white plumage that makes it stand out among other heron species.
This medium-sized heron has several notable physical characteristics.
Its body is primarily slaty-blue with a contrasting white belly and white underwings.
The most distinctive feature is the white stripe running down the middle of its sinuous neck, which helps with identification in the field.
In Illinois, the Tricolored Heron has a limited range. It appears primarily in the southern seven counties during summer months.
Birdwatchers should focus their efforts in these areas for the best chance of spotting this beautiful wader.
Physical Characteristics:
- Size: Medium-sized, slender build
- Coloration: Blue-gray body with white belly
- Bill: Extremely long bill
- Breeding Plumage: Features distinctive buffy plumes
The Tricolored Heron prefers quiet shallow waters for feeding. It can often be observed wading belly-deep as it hunts for small fish and aquatic creatures.
During breeding season, these herons develop special plumage.
Breeding adults display buffy plumes that enhance their elegant appearance and play an important role in courtship displays.
6. Green Heron
The Green Heron (Butorides virescens) is a small, stocky heron that can be found throughout Illinois.
Unlike its taller relatives, this heron stands only 41-46 cm in length, with relatively short legs and a thick neck that’s often pulled in close to its body.
Its appearance is quite distinctive. The Green Heron displays a beautiful blue-green back, contrasted by a rusty-colored neck and dark cap.
This coloration provides excellent camouflage when hunting near water edges.
These birds are masters of patience. They typically adopt a crouched position in vegetation, remaining perfectly still as they wait for prey.
This hunting style makes them somewhat difficult to spot despite their colorful plumage.
Green Herons prefer small bodies of water like ponds, streams, and marshes.
They’re particularly fond of areas with dense vegetation where they can hide and hunt effectively.
Unlike some heron species that form large colonies, the Green Heron tends to be solitary and secretive.
They’re most active at dawn and dusk when they feed on small fish, amphibians, and aquatic insects.
One fascinating behavior sets Green Herons apart: they’re among the few birds known to use tools.
These clever birds sometimes drop bait (like twigs or insects) onto the water’s surface to attract fish within striking distance.
The Green Heron is part of a complex of similar small herons that are sometimes considered a single species called Green-backed Heron when grouped together.
7. Black-Crowned Night Heron
The Black-crowned Night Heron (Nycticorax nycticorax) is a stocky bird compared to other herons.
It has a distinctive appearance with its black cap and back, pale grayish body, and red eyes.
These birds are known for their compact build and shorter legs than typical herons.
Unlike other herons, Black-crowned Night Herons are primarily nocturnal, becoming most active at night or dusk. This nighttime hunting behavior is reflected in their name.
In Illinois, these herons are common migrants and uncommon summer residents.
They can occasionally be spotted during winter, though this is rare.
Their preferred habitats include:
- Marshes
- Swamps
- Ponds
- Lakes
Young Black-crowned Night Herons look noticeably different from adults.
Juvenile birds display a brown and streaky appearance, making identification challenging for new birdwatchers.
These herons are colonial nesters, typically gathering in large rookeries.
They find safety in numbers and often return to the same nesting sites year after year.
The Black-crowned Night Heron is currently listed as endangered in Illinois.
However, researchers have noted that these birds are thriving in Chicago, prompting studies to understand why urban environments might be beneficial for their population.
Bird watchers can identify them by their distinctive “quock” call, often heard as they fly overhead in the evening hours.
8. Yellow-Crowned Night Heron
The Yellow-crowned Night Heron (Nyctanassa violacea) is a distinctive wading bird with a stocky body and relatively short legs.
Adults have a black head with a white cheek patch and a yellow crown that extends down the back of the head. Their bodies are mostly gray with a blue-gray back.
These herons are fairly small compared to other herons, with large, blocky heads and thick necks.
They typically measure about 22-28 inches in length with a wingspan of approximately 42 inches.
In Illinois, the Yellow-crowned Night Heron holds a special status.
It is listed as endangered within the state, making sightings particularly noteworthy for bird enthusiasts.
Habitat & Range in Illinois:
- Primarily found in the southern two-thirds of the state
- Prefers wooded swamps and wetlands
- Often nests in trees near water bodies
The Yellow-crowned Night Heron is an uncommon migrant through Illinois and a rare summer resident.
Unlike its relative, the Black-crowned Night Heron, this species tends to be more solitary and secretive.
These birds have specific dietary preferences, mainly feeding on crustaceans like crayfish and crabs.
They hunt primarily during dusk and dawn, true to their “night heron” name.
A notable breeding pair was documented nesting in Rock Falls, IL in recent years, providing hope for this endangered species’ presence in the state.