Great Blue Heron 

Ardea herodias 

By Chad Carson 

The Great Blue Heron or Ardea herodias is the largest and most widespread heron species in North America.  They can be found in wetlands throughout the United States and Southern Canada.  Adult Great Blue Herons can stand about 4 feet tall and have a 7 foot wing span.  The feathers of these birds are blue-gray on their body and wings.  The underside of the neck is white with black streaks and they have black plumes above their eyes. 

 The species is classified in the phylum chordate, class Aves, order Ciconiiformes, family Ardeidae, genus Ardea, and species herodias.  The family Ardiedae includes other herons, egrets and bitterns.  The genus Ardea dates back to around 14 million years ago and has changed little in the last 1.8 million years. 

The Great Blue Heron is a wading bird and feeds mostly on fish.  However they will also go after insects, small mammals, birds, small reptiles and amphibians.  They use a keen sense of vision and hearing to locate their prey and use their bills to stab it.  They may walk slowly to their prey or simply stand still and wait.  Sometimes they may even hunt prey outside of the water.  Great Blue Herons are active both during the day and night.

 These Herons nest in large colonies will over kinds of herons that can number in the thousands.  They build their nests in trees that can be over 100 feet tall.  The males gather the materials and the females build the nest.  These nests can be as wide as 40 inches.  The female heron can lay about 6 eggs but 4 at best may survive to adolescence.  It is not abnormal for 1 or 2 chicks to be kicked out of the nest by stronger siblings.  The parents feed the chicks with regurgitated food from the hunt.  The chicks will also throw up at any intruder that might want to eat them.

 The Great White Heron is a subspecies of the Great Blue Heron that lives in Florida.  They are somewhat bigger than the normal Great Blue Heron and are completely white.  They reside in the mangrove swamps on the Florida coast.

 The Great Blue Heron can be a pest, especially to backyard pond owners and fish hatcheries.  The Herons will eat the fish that were put into those ponds and hatcheries.  That is precisely not what the owners want to happen to their fish.  Pond owners sometimes place heron decoys to discourage the heron because they do not like to hunt in groups.  Netting can also be used to protect fish from hungry herons.  Herons are also hunted to stop them from eating the fish.

Written spring 2004, as a service learning project for Dr. Gary Coté's Biology 102 class at Radford University.  Copyright Pathways for Radford.