Excerpt:

The 9.7-acre nesting area for the endangered California least terns at Alameda Point recently received a new layer of sand. On Sunday, April 13, a dozen volunteers showed up for the last work party prior to the nesting season.

Sixty dump-truck loads of sand were delivered to the site on the former Alameda Naval Air Station’s runways in March. U.S. Fish & Wildlife Service (USFWS) paid for the project. Once workers moved the sand into place, USFWS joined volunteers to set up a numbered cinderblock grid system for recording least tern behavior. They also distributed chick shelters and oyster shells for the chicks to use as protection from the elements and predators. The shells make it more difficult for avian predators like red-tailed hawks and peregrine falcons to spot the chicks The task of the day was distributing oyster shells around the site. The shells provide a nominal amount of sun protection for chicks and, in theory, help the chicks hide.