Herons and otters and grebes, oh my!

By Paul Belz

Wilderness areas are precious, and must be preserved. Wildness also thrives everywhere around us, including in a small Oakland park near Interstate 24. Ron Felzer, an instructor in Merritt College’s Environmental Studies Department led a December hike in Temescal Regional Park. He mentioned that Temescal Creek has flowed through this region for ten million years, providing healthy habitat for wildlife, native plants, and Ohlone settlements. The creek used to end at the San Francisco Bay, but the developing Hayward Fault turned it in a new direction.

Hayward fault graphic from park display.

Hayward fault graphic from park display.

 

Hydraulic engineer Anthony Chabot dammed the creek during the 1860s to form a reservoir for the little town of Oakland.  East Bay voters passed a tax to create the East Bay Regional Park District in 1936.  “Imagine that,” Ron mused, “people voting to tax themselves during the Great Depression!” The 54-acre Chabot Regional Park, Redwood Regional Park, and Tilden Regional Park were the first three preserves.

Fox sparrow.  Photo: Damon Tighe

Fox sparrow. Photo: Damon Tighe

Ron led the thirty hikers to a white alder, a local tree that usually lives on riverbanks, but thrives here because of the park’s sprinkler system. Alders produce fruits that feed many insects; yellow-rumped warblers and Townsend’s warblers eat insect eggs and cocoons that form on the bark. They also fly in wide arcs to catch flying bugs. Many yellow-rumped warblers gathered around us and filled the air with their “Chip! Chip!” Ron was pleased to see a rarer and more brightly colored Townsend’s. “I see about one of them to a hundred yellow-rumped warblers,” he commented.

A Stellar’s jay squawked from a coast live oak. These evergreen oaks have small, tough leaves that hold water during summer droughts. Stellar’s jays and their cousins the scrub jays bury their acorns to hide them from other animals that feast on them. Jays are members of the corvid family, which includes the common raven that flew past calling “Rawwwnnnkkk!” Ron mentioned that ravens are bigger than the closely related crows. The smaller birds, who yell “Cawww! Cawww!” resemble large blackbirds, and their feathers look like they’ve been neatly trimmed.

Lake Temescal was full of aquatic birds. We easily spotted a great blue heron, followed by the slightly smaller great egret. Ron pointed to a juvenile black crowned night heron. Black crowned night herons are gray and white as adults; young ones are brown so they can blend with aquatic plants. They prey on smaller animals such as insects, crayfish, and small fish. This one seemed unconcerned with the fact that we hikers were using binoculars to stare at it.

Ron shared facts about the many ducks that drifted through the lake. Mallards are dabbling ducks; they point their tails in the air as they grab plants that grow on the lake’s bottom. Buffleheads, goldeneyes, and ruddy ducks dive to find their food. They limit their air when they dive by shutting down most of their bodies. Their heads stay active to propel them, and their heads work to find and grab food.

Dabbling ducks’ legs are located around the middle of the body. This adaptation lets them swim and walk on land. Diving ducks’ legs are located towards the rear of their bodies; they are restricted to water. Ron showed us some brownish gray pied billed grebes. These little birds are not ducks, but they also dive to forage. “I don’t think I’ve ever seen one on land,” Ron reflected, and mentioned that they build floating nests.

Ron described coots’ unique adaptations. Their long, frilled toes allow them to dive; their legs are located in the middle of their bodies, allowing them to walk on land. These black birds with white beaks live in marshes, and sometimes gather on golf courses. They are members of the rail family. Clapper rails, Virginia rails and other members of this family tend to be secretive, but “coots seem frustrated if you don’t stare at them,” Ron laughed as several swam close to the shore.

A spotted sandpiper surprised us as it foraged for insects in the grass. This species and its relatives visit California’s coastal areas by the thousands in winter. One hiker asked Ron why they would migrate from Alaska. He mentioned that insect eaters can find food for twenty four hours during the Arctic summer, but migrate southward when days grow short. “You’d have to have been around for 11,000 years to see exactly how these patterns developed,” he reflected.

A hiker recently photographed an otter in Lake Temescal. “We’d see it if it were here now,” Ron said, “They’re very active.” He wasn’t sure of how the otter wound up in this spot, but speculated that it followed Temescal Creek. Otters are appearing in other East Bay habitats, including Tilden Regional Park!

“The park district is one of many reasons why I live here,” Ron said. He knows treasures when he sees them. Let’s remember to celebrate small wild places!

Lake Temescal.  Photo: Constance Taylor

Lake Temescal. Photo: Constance Taylor

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