The great egret, a spectacular large, white bird stalks the quiet waters of large rivers and lakes looking for prey, such as fish, frogs, snakes, and crayfish.
These carnivorous birds have special adaptations of long legs for wading and a sharp bill designed for grasping or spearing slippery prey. The great egret’s neck, like all herons, contains a modified vertebrae that gives the bird’s neck its characteristic “S” shape and that provides the bird with a swift stabbing motion.
This bird was once hunted for the millinery (hat) trade nearly to the point of extinction by early 1900s. Their spectacular breeding feathers, long flowing plumes originating head, neck and shoulders, literally were worth their weight in gold. Since protection from market hunting in the early 1900s and the ban on DDT in the 1970s (which also affected their populations), this species has recovered.
Both members incubate the eggs. Nest exchanges, in which the male and female exchange the incubation responsibilities, contain elaborate greeting ceremonies that reinforce pair bonds.
Incubation begins immediately upon the laying of the first egg, but this leads to chicks of different sizes in the same nest. Siblicide, when larger nest mates kill smaller ones, often occurs, especially in years when food is scarce and competition is high. Brood reduction seems harsh, but food resources are concentrated on those remaining nestlings maximizing the number of young that are successfully raised. In good years, there is much less competition and siblicide is much reduced. Parents are either unwilling or unable to interefere when chicks begin fighting.
Once rare in the Mississippi National River and Recreation Area, great egret populations slowly moved northward in the 1930s and began to stay for a few late-summer weeks in the Twin City area by the early 1940s. By the 1950s, these birds were a regular summer resident.
Great Egret (Casmerodius albus)
Key ID Features: Very large, white, long-legged, long-necked bird. Legs are black and bill is yellow.
Present in Park: Mid-May through October, but many leave before October. Look for them throughout the Park.
Habitat: The shallow waters of wetlands, rivers, lakes. Nests are flimsy platforms made from twigs and located in trees or tall shrubs. Nests in colonies, often with other species.
Did You Know?
At Lake Onalaska, near LaCrosse WI, the Mississippi River is about 4 miles wide. The combination of water held behind Lock and Dam #7 and water held by damming the Black River form this broad reach of the Mississippi River.