Birds of Ocracoke Series

Birds of Ocracoke: The Great Blue Heron

Text and Photos by Peter Vankevich

“A bird so grand, so majestic, and so picturesque is surely a fitting subject for the artist’s brush,” so wrote Arthur Cleveland Bent in 1927 about the Great Blue Heron.

Bent is the author and assembler of the multi-volume “Life Histories of American Birds,” published over a period of many years by the Smithsonian Institution.

Indeed, the highly photogenic Great Blue Heron (Ardea herodias) is a striking figure whether perched on the ground or in flight with its slow wing beats and the neck folded into an S-shape and has appeared on countless magazine covers, T-shirts and Facebook pages.

The largest wading bird of North America and third largest heron in the world can be seen on Ocracoke year-round, though less in the summer since it does not breed on the island.

Long legs and neck and distinctive grey/blue plumage make it easily identifiable. Aside from some subtle differences, males and females look alike.

This heron’s distribution covers most of United States and southern Canada where there are suitable bodies of water and wetlands habitat. Herons also forage in fields and uplands.

Highly adaptable, with their long legs these larger herons can forage in deeper waters up to about 20 inches.

Solitary hunters, they wade slowly or stand still, peering into the water in search of prey. Using their strong mandibles, they grab their prey or use their dagger-like bills to impale larger fish, often shaking them to break or relax the sharp spines before swallowing them whole.

Their primary food source is fish, though they will eat amphibians, reptiles, small mammals, insects, and even other birds that have the misfortune to get too close to them. Famed ornithologist Alexander Wilson in 1832 noted when the grasshoppers have been thick, he has seen Great Blue Herons feeding in open meadows on these insects entirely, often for two hours at a time; not chasing them but standing very still, allowing the insects to come within reach of their quick beaks.

Within an extensive distribution area, there are both non-migratory and migratory populations with those in the northern range most likely to migrate farther south.

Unlike the vocal, year-round islander, Black-crowned Night Herons, whose squawks can be heard at dusk as they fly over the village, Great Blue Herons are mostly silent.

On a dock, Silver Lake harbor, Ocracoke

The Birds of North Carolina website, managed by the Carolina Bird Club, notes that Great Blue Herons were poorly known as a breeding species as late as the 1970s, with nesting colonies few and far between, mainly in remote swamps.

But with the increase in beaver ponds, reservoirs and other man-made lakes and ponds, Great Blue Herons now nest in most counties east of the western mountains. Increased beaver populations have helped the species elsewhere in the eastern United States and southern Canada.

With its extensive marshes and wetlands, Ocracoke is habitat to 12 bittern and heron species, the most common being the Great Egret.  Both Great Blue Herons and Great Egrets have been reported every year on the island’s Christmas Bird Count since it began in 1981, usually in the seven to 12 individuals range.

Great Blue Herons may nest as single pairs, but mostly in colonies that can vary in size from a few pairs to several hundred. Males arrive at the colony and settle on nest sites where they court passing females. A nest, usually in a tree, has two to five eggs that take a little under 30 days to hatch and six to eight weeks for the chicks to fledge.

In the past, herons and egrets were shot for their feathers used to adorn hats and garments.

The slaughter of these birds went relatively unchecked until 1900 when the federal government passed the Lacey Act, which prohibits the foreign and interstate commercial trade of feathers. Greater protection was afforded in 1918 with the Migratory Bird Treaty Act. With this protection, herons and many other birds have made dramatic comebacks.

In recent years, Great Blue Herons have had to face new challenges. The loss of nesting sites, and deterioration of water quality and wetland habitat affects this species as with many others, including their principle food source, fish.

Toxic chemicals in the environment pose another threat.

Although Great Blue Herons currently appear to tolerate low levels of pollutants, these chemicals can move through the food chain, accumulate in the tissues of prey and may eventually cause reproductive failure.

Listen:  

Courtesy of OhioLINK Digital Resource Commons

Best time to see: Year-round, less so in mid-summer months

Where: Marsh areas, sound side, in flight over island, in village

Click here for the Birds of the Outer Banks Checklist

Unusual sighting on Ocracoke beach, with Great Black-backed Gull in background