Quick Facts · No. 01

Ardea herodias

The Great Blue Heron

Order
Pelecaniformes
Family
Ardeidae
Range
Alaska → Galápagos
Status
Least Concern

North America’s largest heron: a four-foot bird that weighs about as much as a bag of sugar, hunts like a held breath, and nests five hundred to a treetop. This is the short version — the long one is in the field guide.

4.5ft

Standing height

Up to 138 cm — eye to eye with a child

6′7″span

Wingspan

167–201 cm, tip to tip

5.5lb

Weight

Hollow bones. All that bird, less than a housecat

24mph

Cruising speed

GPS-tracked birds in Maine, everyday flight

500+nests

Largest rookeries

Treetop colonies, noisy as a fairground

700kbirds

Global population

Stable to increasing since 1966

Plate I

Drawn to scale

Standing height, in true proportion, with a six-foot person for reference. The great blue comes up to your shoulder.

6′
Human
4′6″
Great blue heron
4′
Sandhill crane
3′3″
Great egret
2′
Little blue heron
Wingspan 6′7″ at full stretch

The Bird Itself

  1. A giant made of air

    Nearly four and a half feet tall, a wingspan over six and a half feet — and a body weight of only five or six pounds. Hollow bones make the giant possible.

  2. Blue-gray, not blue

    Despite the name the plumage is slate gray, with a chestnut-and-black shoulder, a white face, and a black plume sweeping back above the eye.

  3. The folded neck

    Herons fly with the neck coiled into a tight “S” and the legs trailing past the tail. Cranes fly neck-out. It is the fastest way to tell them apart at distance.

  4. A comb on its toe

    Powder-down feathers crumble into a dust that soaks up fish slime. The heron combs it through its plumage with a fringed, pectinate claw.

The Hunter

  1. Built like a spear

    Modified neck vertebrae give the strike its speed — the neck coils and fires like a loaded spring.

  2. The statue act

    A hunting heron may stand motionless for minutes at a time, letting the fish forget it is there. Patience is the entire strategy.

  3. Not just fish

    Fish lead the menu, but herons also take frogs, snakes, crayfish, insects, small birds — and a surprising number of gophers and voles, hunted in dry fields.

  4. The night shift

    Eyes dense with rod photoreceptors let the great blue keep hunting after dark, when most waders have stopped.

  5. Cold-water specialist

    Great blues winter farther north than any other American heron. They need only open water and something in it.

Courtship & the Rookery

  1. The neighborhood

    Herons nest in treetop colonies — rookeries — from a handful of nests to more than five hundred, usually on islands or in flooded groves where nothing can climb to them.

  2. The stick ceremony

    The male gathers sticks one at a time and presents each to the female, who works it into the nest. The exchange is the bond.

  3. Pale blue beginnings

    Two to six dusty blue eggs. Both parents incubate, for about four weeks, and both feed the young.

  4. Sixty days to the sky

    Young herons make their first flights at roughly two months, then come back to the nest for several more weeks of free meals.

Survival

  1. The hard first year

    Roughly two out of three young herons do not survive their first year. The ones that do can live fifteen years and more; the banding record stands near twenty-five.

  2. Eagle trouble

    Recovering bald eagle populations raid rookeries for eggs and chicks, and can push an entire colony to abandon a site. Maine has lost 93% of its island-nesting pairs since 1983.

  3. A sentinel species

    Contaminants concentrate up the food web into heron tissue and eggs. Scientists on the St. Lawrence have tracked mercury, PCBs and flame retardants in heron eggs since 1991 to read the health of the whole river.

  4. Wetlands are everything

    The heron's future rides on wetlands. Protect the marshes and the river bottoms and you protect the bird.

Keep going

Twenty-one chapters, properly sourced.

Identification, migration, hunting, rookeries, calls, adaptations, threats — the whole bird, with citations.

Read the field guide See the prints