Egrets Take Up Residency in Downtown Oakland

Birders seek protections by copying a Santa Rosa solution, but that fix won’t fly in Oakland.


Published:

Photo Gerry Traucht

(page 1 of 2)

 

Twig in beak, a snowy egret glides past the clock face of the Tribune Tower in downtown Oakland, and lands in the thick foliage of a tall ficus tree at 12th and Harrison streets, just minutes from City Hall. The tree, which extends over several lanes of traffic, is home to a colony of egrets and black-crowned night herons—large wading birds that are a familiar sight along the margins of Lake Merritt and the San Francisco Bay, where they hunt. But each spring, the birds nest in a clump of ficus trees in downtown Oakland, raise their chicks high in the trees—and splatter vehicles and sidewalks with streaks of white guano.

Each time parent birds return with food, a cacophony of squawks erupts within the trees, as hungry chicks flap wings and jostle for position, sometimes shoving siblings out of the nest. On the sidewalk, ants crawl over the lifeless form of a chick that died when it hit the concrete. Farther along the street, a speckled baby night heron that landed unharmed in a playground but is not yet able to fly, peers at the world of humans with large brown eyes.

Welcome to the amazing, messy, and sometimes tragic, intersection of big birds and the big city. How large the Oakland colony is no one knows for sure, but advocates hope to find out this year, as they launch a project to monitor nests, protect, and educate people about the birds’ role in the ecosystem.

The city of Oakland’s supervising naturalist Stephanie Benavidez said the colony has not been surveyed since it relocated to downtown, after trees on Lake Merritt’s Duck Islands—where the herons previously nested—died and lost their leaves.

The downtown ficus trees provide the colony with welcome shade, but the thick foliage makes it challenging to survey birds. Still, kwok-kwoking chicks and guano accumulation provide Golden Gate Audubon Society’s director Cindy Margulis with plenty of clues.

“Our first priority is to get the herons protected, then generate public enthusiasm about the colony,” said Margulis, who has identified 16 known and 30 possible nesting sites, scattered across several city blocks, with some branches extending over busy streets.

In 2014, five baby herons from the Oakland colony triggered a public outcry when a tree trimmer dislodged them from trees outside the United States Postal Service’s Lake Merritt facility. A federal investigation determined that bird poop was at the root of the fiasco: USPS hired the tree trimmer because it was tired of washing poop off trucks that its workers parked under the trees where the herons nest. Happily, no birds died, and eventually the United States Fish and Wildlife Service dropped charges against the tree trimmer, after he offered to pay the birds’ rehabilitation costs. The International Bird Rescue Center released the birds at Arrowhead Marsh on the Martin Luther King Regional Shoreline, and Golden Gate Audubon partnered with a local arborist to produce a free brochure that warned against tree trimming March through August, because doing so “can eliminate valuable nest sites.”

The postal episode also underscored broader challenges that the colony faces. Bolinas-based heron expert John Kelly said it’s fairly common for herons to nest in urban areas, perhaps because they encounter fewer natural predators, but it’s even more common for baby herons to fall from the nest. “You can go to the most remote nesting sites, and you’ll find baby birds falling out of nests,” Kelly said, explaining that herons lay three to four eggs that don’t hatch at the same time. “That means chicks of different ages fall out, starve, get killed by their siblings, or get pushed out of the nest and end up on the ground.”

But as Margulis observed, real estate is at a premium in Oakland, including for birds. “Herons nest in sizable trees near water, so they’re using what’s available—mostly ficus trees on city blocks. These trees don’t have any understory of vegetation that would cushion a baby bird’s fall and provide a means for an unflighted young bird to climb back up again. Unfortunately, without protective zones beneath those trees, Oaklanders will be likely to encounter injured baby birds on downtown sidewalks and streets in need of some help.”

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