Grey Heron vs Great Blue Heron

Grey heron with a freshly-caught fish in its beak
© Angyalosi Beata/

Written by Hannah Ward

Updated: July 10, 2022

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Herons are large freshwater birds that are best known for their long-legged and long-necked appearance. There are more than 60 recognized species of herons in the world and they can be found on every continent except AntarcticaGrey herons and great blue herons are some of the most common, with great blues herons being the largest herons native to North America. At first glance they can look quite similar, but luckily there are actually some distinct differences that we can use to tell the two apart. So join us as we take a closer look at grey herons vs great blue herons.

Comparing Great Blue Heron vs Grey Heron

The great blue heron and gray heron differ in habitat, location, size and appearance.

Grey herons and great blue herons are both members of the Ardeidae family group. There are four subspecies of grey herons and five subspecies of great blue herons. The great blue heron subspecies Ardea herodias occidentalis is native to Florida and the Caribbean islands and was originally classified as a separate species and known as the great white heron.

Great Blue HeronGrey Heron
Species NameArdea herodiasArdea cinerea
SizeHeight – 45 to 54 inches
Length – 36 to 54 inches
Wingspan – 66 to 79 inches
Height – 40 inches
Length – 33 to 40 inches
Wingspan – 61 to 77 inches
DistributionNorth America, Central AmericaEurope, Asia, parts of Africa
HabitatVirtually any wetland habitatAny wetland habitat shallow enough to wade in
PlumageGray neck, black and white down the front. Light colored head with white face. Grayish-blue flight feathers, reddish-brown thighs, reddish-brown and black stripes on flanksGrey body and wings, some black on flanks. White head and neck with black stripe extending from eye
BillDull yellow. Orange at beginning of breeding seasonLong, straight, pinkish-yellow
LegsGrey outside of breeding season, orange duringBrown
DietPrimarily small fish, but also larger fish, crabs, rodents, reptiles, and amphibiansFish, frogs, toads, insects, small mammals, juvenile birds
PredatorsAdults: bald eagles
Juveniles and eggs: turkey vultures, ravens, crows, hawks, black bears, raccoons
Adults: no main predators
Juveniles and eggs: crows and kites
LifespanAverage 15 years, oldest approximately 25 yearsAverage 5 years in the wild, but oldest recorded 23 years 9 months

The 4 Key Differences Between Grey Herons and Great Blue Herons

Grey Heron vs Great Blue Heron: Location and Habitat

Great Blue Heron flying over water.

Great Blue Herons are the largest herons native to North America

©Tom Franks/

The most important difference between grey herons and great blue herons is their location which is key to determining which species is which. Grey herons are widespread across Europe, Asia, and parts of Africa, where they live in any wetland habitat with water that is shallow enough for them to wade in. If the body of water is deeper, then the key is that there must be shallower areas that are suitable for them. They usually nest in high trees near to the water, although other nesting locations include trees, bushes, cliff edges, and bramble patches. Grey herons are largely absent from the Americas, although recently there has been some sightings of them on islands off the coast of North America.

As we mentioned earlier, great blue herons are the largest herons native to North America. They are widespread across much of North and Central America where they live in virtually any wetland habitat. Great blue herons rarely ever venture far from water and they often nest in trees and bushes near the waters edge. They are hardy birds and can survive the cold northern winters so long as their fishing grounds do not freeze over.

Grey Heron vs Great Blue Heron: Size

One of the main things to look out for when distinguishing between these two stunning birds is their size. To put it quite simply, great blue herons are much larger than grey herons. Grey herons are 40 inches tall and have a length of between 33 and 40 inches. They also have a wingspan that between 5ft and 6ft 5ins wide and weigh no more than 4 pounds, 10 ounces.

Great blue herons are almost twice as heavy with weights up to 7.9 pounds. They also have a larger wingspan of 5ft 6ins to 6ft 7ins. Additionally, they are 36 to 54 inches long and 45 to 54 inches tall.  Great blue herons exhibit sexual dimorphism whereby males are larger than females, although this difference is not great.

Grey Heron vs Great Blue Heron: Appearance

Another distinctive difference between grey herons and great blue herons is their color. Grey herons have a white head and neck with grey bodies and wings. They also have some black plumage on their flanks and wings, as well as a black stripe on their head which extends from the eye and a pinkish-yellow bill which is long, straight, and powerful. Juveniles are a more greyish color and they lack the dark stripe on their heads.

Great blue herons have grayish-blue flight feathers with reddish-brown and black stripes on their flanks. They also have a grayish colored neck with black and white markings down the front of it and a light colored head with a white face. Possibly the most distinctive markings on great blue herons are their thighs which are reddish brown. They also have a large bill which is a dull yellow color.

Grey Heron vs Great Blue Heron: Legs

Grey heron fishing in a lake

The grey heron gets its name from the gray plumage found on its neck, back and wings

©Budimir Jevtic/

Another noticeable difference between these two herons is the color of their legs. Great blue herons have gray legs outside of the breeding season, during which their legs turn orange. However, grey herons have brown legs all year around.

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About the Author

Hannah is a writer at A-Z animals where her primary focus is on reptiles, marine life, mammals, and geography. Hannah has been writing and researching animals for four years alongside running her family farm. A resident of the UK, Hannah loves riding horses and creating short stories.

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