Consumer article - title:
Snow in Silicon Valley: The Palo Alto Egret Rookery
(Birder's World, June 2006)

You're at home wondering what to do without getting into too much trouble. Mom went out to get food and won't be back for awhile. There's nothing to eat until she gets home so you decide to check out the sticks and twigs of the house to pass the time. Your big brother's being a jerk though, and keeps biting you. So you move away from him and preen your new feathers instead.

Welcome to a young snowy egret's life in the rookery at Palo Alto Baylands Nature Preserve. Adult birds have been foraging for small fish and mollusks to build strength the last six months around this marsh- and slough-filled preserve on San Francisco Bay, fighting with other egrets over the best sites and building flimsy stick nests until the female bird lays the first couple of four or more eggs in late March or April.

This large egret rookery took naturalists, birders and wildlife photographers by surprise. 2004 was the first year since its 1948 establishment for a hundred or more of these graceful white birds to nest in the palm trees of the Baylands' bird sanctuary. "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," said Palo Alto naturalist Deb Bartens. Will they show up again in 2005? Nobody knows.

Egrets had chosen other locations in nearby Redwood City and San Jose for nests in the past. Fellow nature photographer Scott Norton told me the Redwood City rookery was empty as he lined up his tripod with over a dozen other photographers and birders at the bird sanctuary one Sunday. It made me wonder about a bird telegraph alerting everybody to the rookery's new address.

Both parents share incubation and nest repair duties until the first nestlings hatch after three or four weeks. 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 the first few days, but after that they regurgitate it into the nestlings' wide-open mouths.

Downy young egrets don't stay weak and helpless for long. I watched 3/4-sized nestlings challenge parental strength, grabbing a parent's bill in their own and jerking the adult around to demand a meal ahead of their hungry siblings. Adult egrets quickly learn to put their bills in range briefly and keep turned away the rest of the time they're at the nest, appearing to ignore their brood. I've also watched parents close nictating membranes over their eyes to prevent gouging when an overeager egret chick grabs on. And the adults squawk loudly to intimidate their own young and keep them away when the food's gone. Some fly off right away after feeding to escape demanding young birds.

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. Then they're transfered to Suisun Wildlife Rescue and other northern California facilities 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.

Snowy egrets at Baylands share their roost 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 opportunity to see night herons active during the day when they're usually sleeping out of sight. I'd been trying to catch them in flight for months, but it had always been too dark to see them when they normally hunt. Night herons couldn't sleep in the rookery during the day 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.

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 around places like San Jose's Almaden Lake Park. Not all of them make it that far if it's a lean year and the parents can't find enough food for the entire brood of four or five chicks. Stronger nestlings muscle their weak siblings out of the way to feed, and weaker birds starve to death and get eaten by the others. In wild settings without human intervention the fallen nestlings die on the ground, and hawks and other predators hunt them. I watched an adult night heron swallow a rag-doll-limp egret nestling that was probably injured or too weak to compete for food.

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 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, and the chemicals made birds' eggs brittle enough to crack before they could hatch. Rescuing fallen egret chicks is probably the least we can do for these beautiful white birds.