Lifestyles of the White and Feathered

Snowy Egret Nestlings at Palo Alto Baylands

(A photo essay based on this article appeared as "Snow in Silicon Valley" in Birder's World, June 2006)

Bored At Home
You're a youngster at home for a few hours. Mom went out to get food and won't be back for awhile. There's nothing to eat until she comes home so you decide to check out the house to pass the time. But your big brother's being a jerk - he keeps biting you. So you decide to preen your new feathers instead.

Parents Get Ready
Welcome to a young snowy egret's life in the rookery at Palo Alto Baylands Nature Preserve. The adults have been foraging for for small fish and mollusks to build strength for the last 6 months around this marsh- and slough-filled preserve on San Francisco Bay. Then they fought with other egrets over the best sites, and built a flimsy nest from sticks in the palm trees.

2004 was the first year since the Baylands' 1948 establishment for a hundred or more of these graceful white birds to nest in the palm trees of its bird sanctuary, according to Palo Alto naturalist Deb Bartens. She adds, "We don't know why they chose the bird sanctuary here, they just showed up and started building nests. There were only five or six pairs nesting last year and none before that." It's become a regular spot for egrets to raise new families.

The female bird lays the first couple of four or more eggs in March or April. Both adults share incubation duties until the first nestlings hatch around three weeks later. Then the race is on for parents to keep constantly hungry young birds fed, and keep themselves nourished too. Adult birds can just drop food on the nest for the nearly helpless newborns in the first few days, but after that they regurgitate it into the nestlings' wide-open mouths.

Care and Feeding
Downy young birds don't stay weak and helpless for long. They'll get big enough to challenge parental strength, grabbing a parent's bill in their own and pulling the adult around to demand a meal. Adult egrets quickly learn to put their bills in range briefly and stay turned away the rest of the time they're at the nest, appearing to ignore their brood. Adult birds sometimes close their eyes to prevent gouging when an overeager egret chick grabs on. The adults squawk loudly to intimidate their own young and keep them away when the food's gone.

Nestlings Go Exploring
After three or four weeks of nest-bound life, the young venture out to nearby branches to explore. Some get shoved out of the nest by siblings or fall out before then, and adults don't feed grounded nestlings. Palo Alto Baylands rangers like Bonnie Natrass pick them up and give them temporary homes in shoeboxes or cat-sized pet crates with a soft nest of paper towels until their transfer to wildlife rescue centers for care and feeding. When they're big enough to be released, the birds get a limo ride back to the rookery they fell out of to start adulthood in a familiar place. The older nestlings climb and fly back up to the nest after venturing out to keep getting food from the adults. They want to keep getting a free lunch.

Sharing The Roost
Snowy egrets share their roosts and nesting habits with bigger great egrets and stocky black-crowned night herons. Great egrets, night herons and other snowy egrets steal sticks for their own nests while parents are off foraging for nestlings, who cower out of the way of the thieves. Nesting time provides a rare occasion to see night herons during the day when they're usually sleeping out of sight. Night herons couldn't sleep in the rookery in daytime anyway. It's a maelstrom of squawking, flapping adults chasing each other away from nests and territories, feeding their young and preening, and nestlings flapping their wings and demanding food. It can be as hectic as an airport at Christmas.

Growing Up Poses Challenges
After a month or more of feeding by adults and growing feathers, fully-fledged young birds fly off to find their own roosts and territory along San Francisco Bay and as much as 30 to 40 miles inland. Not all of them make it that far if it's a lean year and the parents can't find enough food for the single brood of four or five chicks. Stronger nestlings muscle their weak siblings out of the way to feed. The weaker birds starve to death and get eaten by the others. In wild settings without human intervention the fallen nestlings die, and hawks and other predators also hunt the young birds.

Egrets have also survived human hazards. We hunted snowy and great egrets nearly to extinction in the late nineteenth and early twentieth centuries to get their wispy white plumes to use in ladies' hats. We poisoned marine animals egrets and night herons feed on with DDT and other pesticides after World War II. The chemicals made birds' eggs brittle enough to crack before they could hatch, so rescuing fallen egret chicks is probably the least we can do for these beautiful white birds.