The largest and most common heron in North America, the great blue heron is also one of the largest herons in the world, so large it is occasionally mistaken for a crane. Easily recognized by its colorful plumage and widespread range, this is a familiar wading bird for birders of all experience levels.

Common Name:

Great Blue Heron, Blue Crane, Blue Gaulin, Great White Heron

Scientific Name:

Ardea herodias

Scientific Family:

Ardeidae

Appearance:

• Bill: Long, thick, straight, Yellow-gray or orangish below and darker above, brighter in the breeding season
• Size: 45-52 inches long with 80-inch wingspan, very long thin neck and legs, short tail
• Colors: Gray, black, white, yellow, rust, pink
• Markings: Genders are similar with a whitish face, white crown, blue lores and wide black stripe above the eye. The upperparts are medium gray, and a black or rust patch may show on the scapulars. The front of the throat has vertical black and white streaks and a pink wash may show on the sides of the neck. Underparts are pale, and the undertail coverts are white. The primary and secondary feathers are gray-black, but the color is more visible in flight. The eyes are yellow and the legs and feet are dark gray. During the breeding season, long, thin plumes extend from the crown, the lower front of the throat, the breast and the back.
  
  Juveniles are more mottled overall and have less defined, darker head markings.
  
  In coastal areas of southern Florida and in the Caribbean, a plain, off-white color morph with no distinct markings is present, called the great white heron. Previously considered a separate species, this variation is now lumped together with the great blue heron. Another subspecies, the Wurdemann's heron, has an almost completely white head and the typically colored body, and may appear leucistic. These birds are the result of breeding between the standard colored birds and the great white heron.

Foods:

Fish, amphibians, reptiles, insects, invertebrates, birds (See: Carnivorous)

Habitat and Migration:

These herons are widespread and are typically found near water sources that support adequate fish and other marine life for food. Great blue herons can be found in swamps, wetlands, bogs and flooded fields, as well as alongside lakes and rivers, and they will also forage in open agricultural fields for insects. They are even regularly found in urban and suburban areas on golf courses and similar areas that meet their needs. Their year-round range extends through the southern and central United States from coast to coast and even more extensively in the west, including along the Pacific Coast as far as southern Alaska, and they are year-round residents in Cuba as well. In summer, great blue herons spread throughout all of the United States and southern Canada. In winter, northern populations of these birds migrate, and they can be found throughout Mexico, Central America and as far into South America as Colombia, Venezuela and Ecuador.

Vagrant sightings are regularly reported in both Europe and Hawaii.

Vocalizations:

These herons are mostly silent but can be noisy in rookeries. The typical call is a raspy, grunting croak, higher pitched than would be expected for such a large bird. Calls are also common in flight, and young birds use a rapid begging croak to attract their parents' attention.

Behavior:

These herons are solitary outside their breeding colonies, and they forage very slowly and deliberately, either waiting patiently for prey to come within reach or else stepping carefully as they hunt. They stab prey quickly with a powerful thrust of their strong necks, and swallow it whole. Those same long necks are held contracted in a compact S shape in flight while the legs stretch out far behind the short tail, and their wings use slow, steady beats.

Reproduction:

These herons are monogamous and colonial, nesting in large rookeries. Courtship rituals include bill snaps and clattering as well as fluffing plumage or posing to show off their long plumes. A mated pair works together to build a nest of sticks and twigs that is shallow but bulky, with the female doing the majority of the actual construction while the male gathers the nesting material. The nest is positioned 20-60 feet above the ground and is lined with moss, pine needles, leaves or similar material.

The oval-shaped eggs are pale blue or pale green, and 2-7 eggs is typical per brood. While northern birds only lay one brood per year, southern populations may have two broods if conditions are favorable. Both parents incubate the eggs for 25-30 days, and the young birds stay in the nest to be cared for by both parents for an additional 60-90 days after hatching.

Attracting Great Blue Herons:

While great blue herons are not typical backyard birds, they will visit backyards with fish ponds and marsh-like landscaping that includes tall grasses or other native vegetation bordering the pond.

Conservation:

Great blue herons are not threatened or endangered, but they can be susceptible to pollution and toxic chemicals that build up in their aquatic prey, and discarded fishing line is always a problem. Habitat loss can also impact their populations, and they are sensitive nesters that may abandon nests if their rookery is disturbed.

Similar Birds:

• Gray Heron (Ardea cinerea)
• Tricolored Heron (Egretta tricolor)
• Great Egret (Ardea alba)
• Great-Billed Heron (Ardea sumatrana)
• Sandhill Crane (Grus canadensis)
• Black-Crowned Night-Heron (Nycticorax nycticorax)

Photo – Great Blue Heron – Breeding Adult © Andrea Westmoreland
Photo – Great Blue Heron in Flight © Don DeBold
Photo – Great White Heron © Kashyap Hosdurga