The provocative ridgetop stone walls overlooking the Berkeley-Oakland-Fremont side of San Francisco Bay, with mountain views to the east and maritime vistas to the west, play a contemporary ecological role better defined than the conjectural one surrounding their origin. Researchers reason that some civil society beyond reach of our records fashioned them. Their orientation suggests a demarcation, whether defensive or territorial, between Pacific-based and interior North American culture. Today, they serve to keep intact a natural culture predating any human one.
The walls trap soil and moisture and encourage the growth of native shrubs and wildflowers, which build a sheltering habitat similar to that created by English fencerows. Insects frequent the flowers, birds such as the wren tit consume the insects, ground squirrels forage for plant seeds.
The linear preserve extends into the air, where golden eagles sail by in search of ground squirrels, northern Pacific rattlesnakes, lizards and Alameda whipsnakes.
At night, bobcats and gray foxes follow the lines of the stone walls in search of small birds, on the heels of a long-lost community of human wall-builders. On these embellished ridgetops, flora and fauna line up in a link to an unknown past.