Hole in Bodega Head now refueling stop for migrating birds

The Hole in the Head, a rectangular pit more than 100 feet deep, was precisely cut in 1963 by PG&E to hold a nuclear power reactor. Now it has become an unexpected resource.

The artificial aberration in the coastal landscape today is “a happy artifact of the mistake PG&E made” almost 60 years ago.

Once PG&E abandoned the plan, a freshwater pond in the pit at the edge of Bodega Bay attracts a wide variety of migratory and residential birds and insects during the winter.

Typical seasonal visitors at the Hole include warblers, vireos, tanagers, and thrushes. The more common Western migrants include the Yellow Warbler, Yellow-rumped Warbler and Western Tanager. Migratory insect visitors include butterflies: the Painted Lady, West Coast Lady, and Monarch; dragonflies: the Black Saddlebags and Wandering Glider; and damselflies, such as the Familiar Bluet.

As winter turns into spring, year-round avian residents make the Hole a lively spot. A thick bank of willows grows along the bank of the pond and serves as a home to a group of Black-crowned Night Herons. Seagulls, which feed along the coast, occasionally need to bathe in fresh water. After dipping into the pond, they shake themselves like dogs while rising up into the air. Great Blue Herons, Snowy Egrets, Great Egrets, Pied-billed Grebes, Western Scrub-jays and Song Sparrows also can be seen near the Hole.

Jim Tietz, a staff biologist at the Petaluma nonprofit Point Blue Conservation Science, said that the Hole serves as a “refueling” station for birds flying south.

“Any wet habitat that’s perennially wet is going to be very important for migrating birds as a stopover site,” Tietz said. “The birds can find a lot of insects and fruit to eat from the trees and shrubs.”

Before PG&E dug the pit, the terrain at the site of the Hole “was the same as everywhere,” said Peter Leveque, a member of the Madrone Audubon Society, Sonoma County’s chapter of the Audubon Society.

Because the Hole is close to the Pacific Ocean, it attracts a wide variety of disoriented migrants called vagrants. These are eastern migratory birds that are supposed to fly down the east coast, cross south over the Gulf of Mexico and head toward Central or South America.

Many of the eastern migratory species that show up along the California coast breed in boreal forests in Canada. A number of them have a genetically coded map of the stars in their heads, but a small percentage have a genetic mutation that causes them to orient in the wrong direction. They migrate southwest instead of southeast, a phenomenon called “mirror-image navigational migration.”

Many of these juvenile birds, or “first-year birds,” “stack up along the Pacific Coast trying to build up fat,” said Tietz. Most then try to cross the Pacific Ocean but are not able to cross the vast expanse. Others decide not to migrate and overwinter here.

Tietz said conservation efforts should not focus on the birds that are misoriented vagrants.

“Migrant birds need extremely accurate navigation. It’s important to let natural selection run its course,” he said.

Point Blue is able to monitor the populations of species flying down from places further north, such as the Hole, through its research station on the Farallon Islands, a national wildlife refuge located 30 miles west of San Francisco.

On Southeast Farallon Island, Tietz and other biologists assess migrant populations during the fall months, looking to see which species of birds and insects stop to rest. Most bird species migrate at night because they use the stars to guide them, while insects except for moths migrate during the day.

At the Hole, bird and insect enthusiasts can view all the species gathering together before they begin their separate journeys south.

Audubon Society member Chris Dunford brings a group to the Hole four times a year from Yolo County.

“Visitors’ reactions are usually very positive,” he said. “Photographers can get very close to the birds at Bodega Bay.”

Birding is a little bit like a treasure hunt, Dunford said. “You’re not sure whether you’re going to find anything, but when you do, you’re just thrilled.”

He has been coming to Bodega Bay for 28 years, since he first moved to Davis.

Doris Sloan, one of the original activists who helped end the PG&E project, said she has also traveled out to the Hole and brought geology tour groups many times.

“I didn’t think we (the original group of activists) had any idea of what would happen to the Hole, how it would evolve,” she said. “We did have a victory celebration out there after PG&E quit. Then I went back to school and became a geologist.

“I didn’t go back for a couple of years, but by the time I did, it had filled up with water.”

Sloan said she likes what the Hole has become and is proud of her work to save it.

“I love going out there. I think it’s highly unlikely that the spot will ever be developed because it’s now part of a park. It’s in the people’s hands now to enjoy for as long as I can think.”

Sloan said all of her feelings about the power plant and PG&E are in the past.

“What you see now is nature and the beauty of the area,” she said. “It almost makes it worthwhile that there was a hole dug because there wouldn’t be a pond without it.”

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