Photo Credit: Terry Hartley
SCIENTIFIC NAME: Egretta caerulea
STATUS: Breeder. Common in summer, but uncommon in other seasons in Inland Coastal Plain and Gulf Coast regions. Rare to uncommon in spring to mid-summer in Mountain and Tennessee Valley regions, but fairly common in late summer and early fall. MODERATE CONSERVATION CONCERN.
DESCRIPTION: Both male and female little blue herons are similar in coloration with slate-blue bodies and wings, and a purple head and neck. Adults are 24 inches tall with a wingspan of 40 inches, and weigh about 11-12 ounces. During the breeding season the skin around their eyes and the base of their black-tipped bills turn a brilliant cobalt blue. Also, they have long plumes on their crests and backs, and their eyes and legs darken in color. Immature birds are often confused with snowy egrets because they are mostly white, but they have the black-tipped bills to distinguish them, as well as their greenish colored legs, when snowy egrets have distinct black legs with yellow feet. By their first summer, juvenile little blues will begin to transition to adult plumage and will have a mottled, or ‘pied’, blue and white coloration, which they will mostly loose by the second year.
DISTRIBUTION: Little blue herons can be seen throughout the southeast and breed from Kansas, south to Texas, across to Georgia and Florida, and up the Atlantic coast to Maine. In Alabama they can be found across the state, but breed mostly in central and south AL.
HABITAT: Little blue herons can be found foraging in freshwater and marine-estuarine wetlands such as rivers, ponds, lakes, ditches, flooded fields, fish farms, impoundments, lagoons, tidal flats, etc. They also breed in similar wetlands such as swamps, ponds, lakes, impoundments, and often on island habitats in lakes and ponds.
FEEDING HABITS: Little blue herons consume mostly fish, invertebrates, and small amphibians. Their prey varies depending on location, but they are often found eating small fish such as sunfish and minnows, crayfish and grasshoppers, and frogs and tadpoles. They forage during the day by walking slowly along shallow water.
LIFE HISTORY AND ECOLOGY: Herons are known as colonial waterbirds because they nest in large groups called colonies or rookeries. Often they can be found nesting in mixed-species colonies with other heron or egret species. Males will be the first to arrive at a rookery site, and will establish a territory that may start out about 10-11 yards in diameter, but once other birds show up the males may only have a part of a branch or an area as small as a yard in diameter to claim as their own. Many rookeries have individuals nesting close enough that birds could step from one nest to the next. Once females choose a mate, the males will help them to build their twig nests in 3-5 days. After nest construction and copulation occurs, females lay 3-4 pale bluish-green eggs. Both males and females will incubate the eggs for about 3 weeks (22 days) and will then work together to feed their young for 5 weeks until they are ready to leave the nest on their own.
Little blue herons are not known to have problems with predation, but have been known to decrease with increases in cattle egrets, which tend to be more aggressive at rookeries. With little population information known for these herons in Alabama, it is hard to say how their populations are doing, but overall they have seen a decrease across their range.
The oldest known little blue heron in the wild was almost 14 years old.
Rodgers, Jr., James A. and Henry T. Smith. 2012. Little Blue Heron (Egretta caerulea), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/145
Author: Carrie Threadgill, Nongame Wildlife Biologist, Division of Wildlife and Freshwater Fisheries