Gull protection fence to go up in 2023

Low lake means California Gulls will need protection from coyotes next spring

As California weathers another drought and Mono Lake’s level continues to drop, the landbridge from the mainland to one of the world’s largest California Gull nesting colonies is re-emerging, and with it, concern for the gull population put at risk of coyote predation.

Lake level projections for next year indicate Mono Lake, which entered the drought well below the required management level that would buffer it from these problems, will be at a dangerously low level for nesting gulls because the landbridge will be further exposed. A narrower water channel, shallow water, and exposed shoals will allow coyotes easier access to vulnerable gull eggs and chicks. Anticipating this, Mono Lake Committee staff are once again planning to install the temporary electric fence that successfully protected the gulls five years ago.

Familiar fence, new route

In early 2017 the Committee, in partnership with land management agencies, installed a mile-long, solar-powered electric fence. The fence was the type normally used for livestock—a light mesh construction designed for temporary setup and quick adjustment. While fence installation across a mile of barren, silty, alkaline lakebed was anything but easy, the fence was highly effective.

In early fall of this year, we began surveying the landbridge for fence installation once again. It proved challenging even to land the boat on the landbridge because the water was only about a foot deep for over 70 yards to the shoreline. After paddling the boat to the exposed muddy shore, we walked across the landbridge to map out the fence’s length, which is projected to be more than a mile long. Before leaving the exposed island, we installed a camera at the landbridge’s edge to track the changing shoreline.

Back in Lee Vining, we have pulled the fence and solar panels from storage and prepared them for redeployment. Committee staff are discussing logistics, permitting, and funding for the effort with California State Parks and the California Department of Fish & Wildlife. The fence requires detailed coordination and cooperation with land management agencies prior to the arduous winter installation before the California Gulls arrive to breed and nest in spring 2023.

Stop-gap protection measures

In November 2021, the Committee planned to install the fence for the 2022 nesting season. However, a wet December ensured that Mono Lake would stay around the 6380-foot elevation level for the nesting season—the minimum level that keeps the landbridge from being critically exposed. When Mono Lake drops below 6380 feet, landbridge exposure begins to accelerate, creating increasing opportunities for coyotes to reach the gull nesting habitat.

In consultation with California Gull biologists from Point Blue Conservation Science, a decision was made to deploy a monitoring system of six motion-detecting wildlife cameras strategically placed across the length of the exposed landbridge. On three occasions we were alerted to coyotes patrolling the edge of the landbridge, but there was no photographic evidence of coyotes attempting to access the nesting islets. This was confirmed when Point Blue conducted their annual California Gull study and found no coyote activity at the nesting sites.

However, with the landbridge expected to expand in the months ahead, action is needed. Until Mono Lake can rise significantly closer to the Public Trust lake level mandated by the State Water Board, the Committee will stay ready to implement these kinds of stop-gap measures in order to protect the gulls. To permanently protect the gulls and solve countless other problems in the Mono Basin there is only one solution—raise Mono Lake.

This post was also published as an article in the Fall 2022 Mono Lake Newsletter. Top photo by Bartshe Miller: In preparation for putting up the gull protection fence, Committee staff installed a camera on the landbridge to observe changes in the shoreline as Mono Lake continues to drop this fall.