Impressive Great Blue Heron likely to be found in all 88 Ohio counties

The bird family Ardeidae (ar-dee-ih-dee) includes the bitterns, egrets, and herons. Nearly 75 species wade waters worldwide, with representatives on every continent but Antarctica. An even dozen is found — or has been found — in Ohio.

Many Ohio herons and their allies would not be familiar to most people, excepting birders. Two of them are great rarities in our part of the world. The reddish egret has been found only twice in the state, and the tricolored heron appears every few years. Both are vagrants from the Deep South.

Another southerner, the little blue heron, is somewhat more frequent but still rare, as is the yellow-crowned night-heron. Ohio is at the northern limits of its breeding range. Sticking out like lanky-legged sore thumbs are great and snowy egrets. These snow-white herons are also southerners, but their ranges are expanding northward in recent decades.

The somewhat enigmatic cattle egret is indigenous to Africa and Eurasia but began spreading far and wide in the 20th century. Ohio’s first record came in 1958 and it has even nested but remains a rarity.

Two bittern species occur here, the diminutive least bittern and the much larger American bittern. Both are denizens of emergent marshes, and people have not treated their habitat well. About 90% of Ohio’s wetlands have been lost since settlement, and consequently bitterns – and scores of other species – have become much rarer.

More common than suspected is the black-crowned night-heron. Their habits make them elusive, though. The well-named bird is mostly nocturnal and tends to hole up in thick cover during the day.

Ohio’s second most common heron is the green heron. About the size of a crow, green herons nest in every county, and favor well-vegetated ponds, lakes, streams and the like.

Number one on Ohio’s heron roster is the conspicuous great blue heron. Probably everyone reading this has seen this species many times. Seeing one of these impressive beasts is like clapping eyes on a living, breathing pterodactyl. Flushed from a riverbank or pond shore, one of these gargantuan fish-spearers launches itself into the air with cumbersome rows of its massive wings, uttering god-awful, frightening croaks.

Like its little brother the green heron, great blue herons probably breed in all 88 Ohio counties. Unlike its diminutive sibling, which breeds solitarily and expertly conceals its nest, the great blue is an extroverted nester.

Great blue herons nest communally, their collective aggregation of nests known as a rookery. Sometimes rookeries are small, with only a handful of nests. But if sited in an especially favorable locale, rookeries expand over the years and can become quite large. The largest is probably the rookery on West Sister Island in western Lake Erie. At its peak in the early 1990s, it contained nearly 2,500 nests.

Most rookeries probably support a maximum of a few dozen nests. The accompanying photo of a Ross County rookery has about 50 nests (not all are visible in the image). Conspicuous local rookeries include one along the Olentangy River at State Route 315 and Hyatt Road. Another is on a small island in the old quarry behind Shrum Mound off McKinley Avenue, near Marble Cliff.

Many herons, including the great blue, were persecuted in the late 1800’s for the millinery trade. The birds’ showy plumes were used to adorn hats, and heron ranks were decimated in many regions. An end was put to the frivolous slaughter at the dawn of the 20th century, and great blue herons and others have become much more common, and many species continue to increase.

Naturalist Jim McCormac writes a column for The Dispatch on the first and third Sundays of the month. He also writes about nature at jimmccormac.blogspot.com.