The great blue heron (Ardea herodias) is an impressive and increasingly common sight in the Cuyahoga Valley. The success of nesting colonies in the valley is a reflection of favorable habitat created by beavers, along with protection of the valley by the National Park Service; Cleveland Metroparks; Metro Parks, Serving Summit County; the City of Akron; and other organizations and individuals. Use this bulletin to learn more about great blue herons and to find the best places to observe them.
Physical Features and Distribution
The great blue heron is the largest heron found in North America. Great blue herons stand four feet tall, weigh slightly over four pounds, and have a wingspan of nearly seven feet. These herons are generally seen in their nesting colonies or in wetlands and along the river, where they feed on small fish, amphibians, and a variety of aquatic invertebrates. The migration patterns of the great blue heron in Ohio are extremely variable. Some birds travel to the Gulf States. Others fly just one or two states south. The remainder stay throughout the year.
Great blue herons nest in colonies, called heronries. Nests are typically in 30-70 foot high trees surrounded by water. Both the male and female share in nest building and caring for the young. Depending on the severity of the winter, males usually start returning to the nesting areas in early February to claim their nests. Two to three weeks later the females arrive, and seasonal monogamous pair bonds are established. From early March to early April is the best time to observe nest building. A male will gather a stick and present it to the female, who takes the stick and adds it to the nest, strengthening the pair bond. Later the inside of the nest will be lined with find twigs and leaves. Great blue herons are known to use nests from previous years, although it is not known whether or not the same individuals use the same nests each year.
Incubation and Fledging Development
After courtship and mating, the female heron lays three to seven eggs over a period of a few days. Both parents share in incubating the eggs for approximately 28 days. The eggs are rolled every few hours so heat is evenly distributed to the developing embryo. Hatching occurs over the span of a few days, typically in late April or early May. May and June are busy months at the heronries, when adult birds can be observed bringing food to the growing nestlings. The young herons fledge after 56 to 60 days, usually by early July.
Last updated: June 14, 2020