- Appearance: blue-gray body, dark blue feathers on insides of wings, long legs, long and dagger-like orange beak, black or blue stripe around eye
- Height: 3 to 4.5 feet
- Despite their height they only weigh 5-6 lbs
- Wingspan: 65-80 inches (about 5.5 to 6.5 feet)
- Status: least concern, populations are increasing
- Nearly hunted to extinction for their fashionable blue plumage in the 1800s
- Habitat:
- Open coasts, salt marshes, riverbanks, lakes, swamps, may nest in forests
- The great blue heron is the largest heron in North America and the most common
- Pure white subspecies can be found in Florida = “Great White Heron”
Legend:
Common Year-Round
Breeding Range (Summer)
Common in Winter
Great Blue Herons are one of the few species of heron that overwinter in Long Island. They do not migrate. The only populations that migrate are those with seasonal ranges (blue and pink). It is only found in the Americas and parts of Europe.
- Diet:
- Mostly fish, but may also eat crustaceans, frogs, salamanders, turtles, snakes, and small birds and mammals
- Can hunt during the day or at night
- Wade through water, stand and wait, when prey comes close they strike with beak
- Spend up to 90% of walking hours hunting
- Sometimes they shake their prey around to disorient them before swallowing them whole
- Aggressively defend their feeding territories from other herons, gulls, and sometimes even humans
- Sometimes congregate around fish hatcheries and backyard ponds for easy food source, which can become a nuisance to fish farmers and homeowners
- Migration:
- Only certain populations migrate – see map above
- Populations near the coast can survive during the winter because they have access to open water
- Inland populations need to migrate because during winter their source of water freezes
- Migrate during the day alone or in small flocks
- Average flight speed of 25 mph, but can fly up to 35 mph
- Breeding season begins February-March, southern migration begins September-October
- Widest wintering distribution of any heron species in North America
- Nesting:
- Breeding great blue herons gather together in colonies called “heronries”
- One colony can have 500 or more breeding pairs (1,000+ birds)
- Great blue herons are extremely territorial around their nesting grounds
- Breeding colonies settle within 2 to 4 miles of their feeding grounds
- Both sexes grow long feathers on their necks and backs during breeding season
- Males collect sticks from ground, trees, and unguarded/abandoned nests, females weave the sticks into their own nest
- Nests are usually built at least 100 feet off the ground
- In salt marshes nests are built on the ground using large blades of grass
- Nests can be reused over many years, in which case material is added each year
- Nests can reach up to 4 feet across and 3.5 feet deep
- Great blue herons have one mate per year, but they find new mates every year
- Average brood is 2-6 pale blue eggs
- Parents care for their young until they can fly on their own
- Fledglings learn to fly at about 60 days old
- Great blue herons normally live 15 years, but one was found to be 25 years old
- Breeding great blue herons gather together in colonies called “heronries”