Great Egrets Nest in Alameda

Great Egrets Nest in Alameda

Recently while bird watching at Crab Cove, my friend and I saw three Great Egrets wading just offshore in the low tide. Hunting and moving slowly through the water that rose on their long legs nearly to their bodies, with their long necks outstretched, yellow beaks poised like daggers, ready to strike, and white feathers shining in the early morning sun, they made an impressive tableau. We watched as the first one stabbed and grabbed a small fish on its first try. Then the second bird tried one, two, three times and finally came up with a small wriggling fish. Down the hatch! It takes persistence and plentiful fish to fuel those 3 ½ foot-tall bodies.

We’re fortunate in Alameda to have a nesting colony on Bay Farm Island. The Great Egrets and their smaller cousins, the Snowy Egrets, use the trees in one of the lagoons as their nesting colony. Every spring they arrive. The males choose the spots they prefer, usually high up in the trees, and then set about attracting a mate. Their large nests of sticks dot the trees and their cacophony of guttural calls resound around the lagoon. This is just one of a few nesting sites around the Bay Area.

In the 1800s, Great Egrets nearly became extinct for fashion. Their long white plumes were highly sought after for ladies’ hats. When conservationists finally stopped the slaughter of the birds in the early 1900s, the egrets were able to make a comeback. They became the symbol of the Audubon Society. Their ranges have expanded and they’ve made good use of habitats that humans have created for them, such as our Bay Farm lagoons.

I suspect the egret trio my friend and I saw might be a family group from the Bay Farm nesting colony. Egret pairs lay two to five greenish-blue eggs with two to three days between each egg resulting in chicks that are each two to three days apart in age. The older siblings are bigger and stronger and more likely to survive in years where food is scarcer. The younger chicks survive in years of plentiful food, when all the babies can reach adulthood. Both parents feed the growing young with fish, frogs, and small mammals. Around seven weeks old, the young begin to test their wings, but won’t fledge on their own until 10 to 12 weeks. They’re almost identical to the adult birds and very hard to tell apart. Their first year of life is hazardous with more than 76% not making it to a second year.

Egret migration is an interesting topic. Studies of an egret colony in Sonoma County tracked several birds with backpack transmitters attached to them. One Great Egret stayed close to home during the non-breeding season. A second Great Egret took a long flight down to the Gulf of Mexico and then came north through Arizona, the Sierras, and finally back to Sonoma County. Scientists can’t yet explain why one migrated and another didn’t. They are documented to migrate as far south as Central America. Kids might appreciate https://www.egret.org/resources-for-teachers-families, an especially wonderful pair of coloring books featuring Ephran the Great Egret. We can all appreciate their comeback story and their graceful beauty.

Sharol Nelson-Embry is the retired Supervising Naturalist at the Crab Cove Visitor Center, EBRPD. She currently serves on the Board of the Golden Gate Audubon Society. Sharol also started www.cocoacase.com which features “bird friendly” chocolate.