Tricolored Heron

Egretta tricolor

(c) John Cassady
  • ARDEIDAE
  • Herons, Bitterns, Egrets
  • Ciconiiformes
  • Garceta tricolor
  • Aigrette tricolore
Introduction
The Tricolored Heron is built for marsh life: long legs enable it to wade and see down through the water; long toes churn up food and distribute weight over soft mud; a long neck and bill help reach prey; and broad wings can lift the heavy body vertically out of a brushy wetland. Once called the "Louisiana Heron," this colonial nester is a close relative of bitterns and one of only four North American egret species.
(c) Glen Tepke
Appearance Description
The Tricolored Heron measures about 26 inches long and weighs 13 ounces, with a 36-inch wingspan. Long, slim, and ornately colored, this fancy egret has notably long legs, neck, and bill. Contrasting with straw colored back plumes, the upper parts, including the head and neck, are slate blue. Below the base of the neck, the under-parts are white. During breeding season, the Tricolored Heron sports a short white head plume, a buffy throat and fore-neck, a blue face, and a blue bill, tipped with black. The eyes are reddish, and the legs pinkish. Nonbreeding adults have a yellow face, bill, and legs; the throat and fore-neck are white. On juvenile Tricolored Herons, rusty red adorns the head, neck, upper back, and the front parts of the wings.
Range Map
Courtsey Kenn Kaufman
Range Distribution
In North America, most Tricolored Herons breed coastally from New Jersey through Florida and then west and south along the Gulf Coast. A few breed into New England and the coastal plain. Populations concentrate around places like Florida's Cape Canaveral, Louisiana's Sabine River estuary, and Texas's mid-coast bays. The Tricolored Heron's winter range covers much of this same area, with most birds withdrawing below North Carolina. Tricolored Herons also breed and winter coastally from Mexico south to Peru and northern Brazil.
 
A legend for the range map to the right can be found here.
Habitat
Tricolored Herons most often breed in coastal wetlands such as mangroves, estuaries, lagoons, and salt marshes, but they also use freshwater marshes, like the Florida Everglades. Wintering birds are generalists that are more attracted by food sources than by a specific habitat type. Rarely found on dry land, Tricolored Herons prefer wetlands with low vegetation and shallow water, suitable for wading up to their chests.
Feeding
Along shorelines and in water as deep as seven inches, Tricolored Herons actively pursue small fish like topminnows, killifish, and livebearers, which together comprise almost 90% of the diet. Other prey items include marine worms, water bugs, and spiders. This egret waits in ambush, then walks methodically, runs or twirls with open wings, and even hovers over fish schools. Typically, the bird then crouches and thrusts out its long neck to snatch up prey.
Reproduction
In colonies with other herons, Tricolored Herons usually nest in short trees, tall shrubs, and mangroves. Males establish territories with twig shaking displays, nest platform construction, and exaggerated preening. Courtship displays include the "snap-stretch," in which the male elongates his body upward, then collapses down with upheld bill, neck folded in an S, and plumes erect. As his neck sways, the male emits an "Unh!" Pairs are monogamous. Males gather twigs and pass them to the female, who constructs a loose nest, with increasingly smaller twigs, and finally, course grasses. Both sexes incubate three to four bluish-green eggs for about 22 days; together they brood, feed, and defend the yellowish hatchlings.
 

For the first week after hatching, parent herons regurgitate clumps of food onto the nest floor, which the hatchlings eat until they are strong enough to be fed directly. Young birds are fed for about seven weeks. When they are able to fly, begging juveniles pursue their parents around the colony. Adults lead the juveniles to feeding areas, where their association appears to end.

Migration
Almost all Tricolored Herons breeding north of North Carolina migrate south; fewer of these egrets are seen along the southern Atlantic seaboard in winter than in summer. Northern migrants winter into the southeastern U.S., the Caribbean, and Central America. Immediately after breeding, the Tricolored Herons disperse, but less widely than other herons or egrets. Spring migration probably starts as early as February and ends as late as early May.
  • 500,000
  • 293,000
Population Status Trends
In North America, Tricolored Heron populations appear stable, but have fluctuated significantly since the 1930s. Overall, Florida's breeding population dropped from an estimated 500,000 to 16,000 between the 1930s and the 1980s. Since the early 1990s, Breeding Bird Surveys and Christmas Bird Counts have recorded several population spikes connected to range expansion along the mid-Atlantic coast as far north as Massachusetts and at scattered sites along the Gulf Coast. Arkansas, Florida, North Carolina, and Virginia list this wader as of "a species of conservation concern." It is a "priority species" in Maine, and a "species of greatest conservation need" in Maryland and New York.
Conservation Issues
Although Tricolored Heron populations appear stable in North America, they are not secure. The wetlands in which this egret breeds and forages are disappearing at an alarming rate, despite mitigation efforts, government studies, and repeated warnings.
 
The state of Louisiana's coastal wetlands is particularly dire, since this state accounted for 67% of total U.S. coastal wetland losses between 1978 and 1990, and as much as 90% from 1990 to 2000. Despite legal efforts like the Breaux Acts, restoration has proven politically and economically difficult. Changes in river channels for navigation, increased silting from the Mississippi, and ground subsidence caused by the removal of oil and gas submerge as many as 47 square miles of marine wetlands per year. This degraded ecosystem is vulnerable to catastrophic events, like hurricanes Katrina and Rita, which submerged an estimated 217 square miles of wetlands in 2005. Before 2005, Tricolored Herons were already declining in large parts of Louisiana at a rate of more than 1.5% per year. Similar patterns have been observed in Florida's Everglades, where some restoration efforts are underway, and along coastal Texas, where no state law protects wetlands.
 
Tricolored Herons are additionally impacted by subsistence hunting in South America and increases in permits to kill herons at U.S. marine farms—a four-fold increase between 1989 and 1996. Nevertheless, aquaculture overall probably benefits this egret by providing food.  Human-created habitats like dredge islands also benefit Tricolored Herons.
What You Can Do
Look for Tricolored Herons at coastal refuges like Huntington Beach State Park in Murrell's Inlets, South Carolina. For an adventurous experience, visit the remote Lacassine National Wildlife Refuge, an Important Bird Area, and part of Louisiana's disappearing coastal wetlands near Port Arthur.
 
Attend a wildlife festival where Tricolored Herons can be seen: Georgia's Colonial Coast Bird and Nature Festival, on Jekyll Island, Georgia; or the Pelican Island Wildlife Festival  outside Sebastian, Florida, the site of the first federal reservation for birds.
 
Respect Tricolored Herons with an 80-meter buffer between yourself and their nesting/roosting sites.
 
For more actions you can take, including Audubon activities, please visit our resources page.
More Information
Visit our resources page for more information about this species.
Natural History References
Frederick, P. C. 1997. Tricolored Heron (Egretta tricolor). In The Birds of North America, No. 306 (A. Poole and F. Gill, Eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.
 
Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, Results and Analysis 1966 - 2005. Version 6.2.2006. USGS Patuxent Wildlife Research Center, Laurel, MD.
 
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.
Conservation Status References
Barras, John A. 2006. "Land area change in coastal Louisiana after the 2005 hurricanes—a series of three maps." U.S. Geological Survey Open-File Report 06-1274.
 

 

Dahl, T. E. 1990. Wetlands: Losses in the United States 1780s to 1980s. U. S. Department of the Interior, Fish and Wildlife Service. Washington, D. C. 13 pages.
 
Frederick, P. C. 1997. Tricolored Heron (Egretta tricolor). In The Birds of North America, No. 306 (A. Poole and F. Gill, Eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.
 
Moulton, D. W., T. E. Dahl, and D. M. Dall. 1997. Texas Coastal Wetlands; Status and Trends, mid-1950s to early 1990s. U. S. Department of the Interior, Fish and Wildlife Service, Southwestern Region. Albuquerque, New Mexico. 32 pages.
 
Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, Results and Analysis 1966 - 2005. Version 6.2.2006. USGS Patuxent Wildlife Research Center, Laurel, MD.
 
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.
 

Williams, S. J. "Louisiana Coastal Wetlands: A Resource at Risk." U.S. Geological Survey Fact Sheet. 3 November 1995.