By Caitlin Bell
A small fish swims amid shoreline reeds in warm estuarine waters. As the fish pauses to suck up bits of floating plant material, the water around it darkens as a huge shadow blocks the sun. The fish tries to dart for cover, but instead is pulled out of the water and thrown high into the air. The fish catches a flash of white before disappearing down the gullet of a hungry Great Egret.
The Great Egret (Ardea alba) is easily distinguished from its larger, bluer cousin, the Great Blue Heron, because of its pure white plumage and long, yellow beak. In the breeding season, the beak may become darker and the legs lighter.
Great Egrets are common along the California coast in winter. In the 19th century, large numbers of these snow-white birds were killed for their sought-after feathers, which were used to decorate hats. In 1953, the Great Egret was chosen as the symbol of the National Audubon Society, which was founded in part to prevent birds from being killed for the feather trade. Nearly 95 percent of the population of the Great Egret was wiped out, but conservation measures have allowed the egret’s population to recover. Great Egrets are adaptable and co-exist well with humans, and can be seen preying on fish and frogs in urban ponds and roadside ditches.
The Great Egret is an ambush predator, known for its ability to stand perfectly still to allow small animals, like frogs and fish, to come within striking range. This bird’s dinosaur-like feet silently plod through marsh mud, and occasionally will follow large animals like cows, and even machines such as lawnmowers, to catch frogs and insects stirred up by their passing.
During the breeding season, Great Egrets can be observed courting mates. Males will display their long, plumed back feathers, called aigrettes, for nearby females. Great Egrets nest in a colony called a rookery where they build flat nests out of sticks and reeds in trees that overlook a body of water. The Great Egret lays 1-6 greenish-blue eggs that hatch after 25 days. Chicks are semi-altricial, meaning that they hatch covered in downy feathers, but are helpless and must be fed and kept warm by their parents. After 45 days the chicks fledge and begin their lives in California’s estuaries.
Photo credits (from top): William Hood, Steve Shinn, Tim Laman.