The Great Blue Heron is the largest and most widespread heron species in North America. With its distinctive blue-gray plumage, bold black and white head markings, and imposing stature, the Great Blue Heron is unmistakable. But there are some key identification tips to look for when trying to identify a Great Blue Heron.
Size and Shape
Great Blue Herons have an elegant silhouette and stand very tall, from around 3 to 4.5 feet in height. Their wingspan measures 5 to 6 feet across when in flight. Compared to other heron species, the Great Blue Heron has a thicker neck that curves in an S-shape when flying or hunting. The body is slender overall. Legs are long and yellowish. The bill is long, dagger-like, and yellowish as well.
In Flight
When flying, the Great Blue Heron keeps its head tucked back against its shoulders. The long neck gives it a very distinctive kinked profile mid-flight. Slow and steady wing beats carry the bird along. Unlike egrets which fly with their slim necks outstretched, herons have that signature compressed S-shape.
Standing
When standing, the same S-curve shape is evident. The neck may be contracted and curved or extended upward depending on activity. Compared to smaller heron species, the Great Blue Heron stands very tall with long legs that contribute to its height. When agitated, the heron may stand fully upright with neck feathers ruffled.
Color Pattern
The Great Blue Heron has a unique color pattern consisting of blues, grays, blacks, and whites. The head has a black cap above and a thick black stripe running vertically behind the eye to the back of the head. The cheeks and throat are white. The back and upper wings are a blue-gray color. The belly and underwings are paler gray to white in color.
Blue-Gray Plumage
The blue-gray plumage covers the bird’s back, rump, wings, and tail. Depending on lighting conditions, it can appear more blue or more gray. When shadows are low and daylight is bright, the blues tend to stand out more. In low light or when shadowed, the plumage often looks more gray.
Black and White Head
In contrast to the subtle blue-grays of the body, the head is a bold black and white pattern. The top of the head is black, as is the thick vertical stripe behind the eye. The white of the cheeks, throat, and forehead set off the dark head markings in a striking high-contrast pattern.
Beak and Legs
Additional identifying features of the Great Blue Heron include its large yellow beak and long yellow legs:
- Beak: The beak is long, thick and dagger-like. The upper mandible is darker while the lower is pale yellow.
- Legs: As with other herons, the Great Blue Heron has very long legs, which are yellowish in color with gray scaly patterns on the upper parts.
Beak Shape
The heron’s large beak is ideally shaped for spearing fish and other prey. The upper and lower mandibles taper to a sharp point. While the upper is darker, the lower is a pale yellowish hue. The beak’s yellow color stands out against the blues and grays of the body.
Leg Length
The heron’s legs are exceptionally long, even for a heron. This allows the bird to wade into deeper water when hunting. The legs are yellowish but fade to a grayish color on the upper portion with flaky or scaly patterns. Bare skin above the tibiotarsal joint appears yellow as well.
Behavior and Habitat
Behavioral traits and habitat preferences can also help identify the Great Blue Heron:
Hunting
Great Blue Herons commonly hunt in shallow wetlands and along shorelines. They stand motionless or move slowly with an upright, patient posture. When prey is spotted, they strike with lightning speed to grasp it in their beak. Fish are the primary prey, but herons also take amphibians, small mammals, insects, and other aquatic animals.
Nesting
Male and female Great Blue Herons build large stick nests high up in trees. Nesting sites are usually located near foraging areas. Nests are re-used and expanded each year. Great Blue Herons nest in colonies containing just a few to hundreds of pairs. Colonies are often found on islands or relatively undisturbed wetlands.
Habitat
Great Blue Herons inhabit a variety of aquatic habitats at low to moderate elevations. These include freshwater and saltwater wetlands, river and lake shorelines, marshes, ponds, and lagoons. They favor areas with shallow, calm waters containing plenty of prey fish.
Distinguishing from Similar Species
The large size, blue-gray body plumage, and bold black and white head make the Great Blue Heron distinctive. But it may sometimes be confused with the following species:
Great Egret
The all-white Great Egret is similar in size but lacks any blue-gray coloration. Its yellow beak is also thinner and longer than the heron’s heavy beak. Great Egrets fly and wade with a straighter, more graceful neck than herons.
Little Blue Heron
As its name suggests, the Little Blue Heron is a smaller, more petite version of the Great Blue Heron. Adults have Solid blue-gray plumage compared to the larger heron’s variegated grays. The Little Blue’s bill is multi-colored with a black tip while juvenile birds are solid white.
Tricolored Heron
Formerly called the Louisiana Heron, the Tricolored Heron is stocky with a white belly, bluish-gray back, and reddish-purple head and neck. The white on its throat extends down the neck unlike the Great Blue’s separated black and white head pattern.
Cattle Egret
The completely white Cattle Egret is a smaller heron species that often associates with livestock in fields. When found near water, it could potentially be mistaken for a Great Egret or Great Blue Heron. But its much smaller size, compact shape, and blunt beak help distinguish it.
Key Identification Features
The following table summarizes some of the main identification features of the Great Blue Heron:
| Feature | Description |
|---|---|
| Size | 3 to 4.5 feet tall; 5 to 6 foot wingspan |
| Shape | Large, elegant; neck forms S-curve in flight and when standing |
| Plumage | Blue-gray back, rump, wings; paler underparts; black and white head |
| Beak | Thick, long, yellowish dagger-like shape |
| Legs | Very long yellow legs |
| Behavior | Patient, standing hunts; spearing strikes for fish |
| Habitat | Fresh and saltwater wetlands; shorelines |
Conclusion
With its large stature, patient hunting behavior, and striking blue-gray and black and white plumage, the Great Blue Heron is one of the most distinctive and remarkable waterbirds in North America. Key features to note are its large size, S-shaped neck, thick yellow beak, blue-gray back and upperwing plumage, and bold black and white head pattern. Taking note of habitat and behavior – like standing in shallow water waiting to spear fish – can also aid identification. With a little practice, anyone can learn to recognize these elegant and widespread herons.
