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Wildlife refuge Aramburu Island in Richardson Bay near Strawberry has recently become home to a young family of oystercatchers.

Black oystercatchers and their chicks have appeared on Aramburu Island near Tiburon, a sign that restoration efforts on the small site are working.

It's the first time the birds have successfully nested in Richardson Bay that anyone can remember and Aramburu Island is now only one of four nesting locations for the species in the bay.

That the oystercatchers -- first seen last month -- are even in the bay is noteworthy, said Rachel Spadafore, restoration ecologist with Audubon California.

"Black oystercatchers are identified as a focal species by the U.S. Fish and Wildlife Service and an Audubon species of special concern due to its rarity and vulnerability to a number of threats," she said. "Threats include sea level rise, ocean acidification, and increased recreational and commercial use of coastal areas."

Despite its name, the bird rarely eats oysters, but rather forages along shorelines for limpets and mussels at low tide. Breeding pairs generally nest at locations with food sources nearby, speaking to the improvements made to the island specifically designed to attract shorebirds.

The Tiburon-based Richardson Bay Audubon Center and Sanctuary has worked to improve salt marsh habitat and restore native plant communities on the trio of islands that are largely the remnants of 1960s development.

"We have been working on the shoreline to make it suitable for breeding and we finished only late last year so this is immediate validation," said Jordan Wellwood, center director. "We also saw the egg shells hidden as we thought they would be. The birds identified this as a good location."


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The biggest of the three islands in the area, Aramburu, is 17 acres thick with non-native plants that make it undesirable for birds. About 60 percent of the island was covered with invasive plants such as thistle, French broom, Harding and pampas grass until restoration work began.

The other two islands -- Pickleweed, about 7 acres, and one simply known as Unnamed Island, 2 acres -- were in better shape ecologically in large part because their elevation is much lower than Aramburu. Pickleweed, jaumea, San Francisco Bay gumplant, Pacific cordgrass, salt grass and marsh rosemary are some of the native plants that grow on the islands. The islands are ideal for attracting wildlife, in part because they are isolated, with Wellwood asking people not get to close via boat to protect the birds.

The islands' existence can be traced back to home construction. When the Strawberry Spit area was developed in the 1960s, a hillside had to be graded and much of the material was placed in the bay, forming a peninsula.

Seals discovered the spot and would haul out there, but dogs would scare them back into the water. In order to protect the seals, a channel was cut, making the peninsula an island, which was later named for former Marin County Supervisor Al Aramburu. The two smaller islands were built from dredge material from a channel that runs along the islands.

It's possible seals that once hauled out on the site could come back.

"They are such gregarious creatures, they need to see one up there to know it is safe," said Kerry Wilcox, sanctuary manager. "It could happen." ------ (c)2014 The Marin Independent Journal (Novato, Calif.) Visit The Marin Independent Journal (Novato, Calif.) at www.marinij.com Distributed by MCT Information Services