It was on a sunny March morning that a group of intrepid volunteers gathered at the mudflats near the mouth of the slough. Their mission: to relentlessly stomp, squish, trod, prod, and dig in the mud.
This is the second year that Elkhorn Slough volunteers have been called forth to an event known as the Mud Stomp, part of the Snowy Plover Recovery Projects, initiated and managed by Point Reyes Bird Observatory Conservation Science biologists. The purpose is to provide nesting sites for the Western Snowy Plover (Charadrius alexandrinus), a species that lays eggs in shallow depressions in the ground or in beach sands above the wrack line. The footprints also provide disruptive ground cover that can help plover chicks, which are flightless for their first month, to avoid predators.
The Moss Landing Wildlife Area is owned by the California Department of Fish and Wildlife.
These mudflats – once a series of evaporation pools in a saltworks – have been used by the snowies for a few years now. But when the mud dries completely it becomes a flat, hard crust unsuitable for nesting. The Mud Stomp creates favorable nesting conditions in an effort to help the recovery of this threatened species.
The group of two dozen volunteers met in the parking lot of the Moss Landing Wildlife Area, just north of the Highway 1 bridge. There we pulled on our rubber boots, swabbed on the sunblock, and strapped on binoculars. Then we got a quick orientation from the expedition leader, Carleton Eyster, who explained the purpose of the program and the routes we’d be taking to and through the various ponds. We grabbed our shovels and set out.
It wasn’t long before the whole group was tromping through the muck, sometimes in a narrow band alongside a channel, other times spread out over a wide area. Occasionally someone would sink knee-deep and require assistance to get free. And there were a few cases of pitching forward into the muck – all part of the fun.
The ponds are north of the slough (see photos for a view) and east of Highway 1. Water levels in these ponds are managed throughout the year to provide roosting and foraging habitat for migratory shorebirds. In early spring, water is released through culverts to allow some of the ponds to begin to dry. During a brief two week window in March or April, footprints and shovel relief can be created in the drying mud. From March through September, snowy plovers and other shorebirds (American Avocet, Black-necked Stilt, and Killdeer) will lay eggs and raise their young in the ponds, foraging on brine flies and other prey along the wet margins of the old borrow channels, which were created when the levees were built. Throughout the summer, seawater is periodically brought in through gated culverts, providing a mosaic of wet and dry areas to meet the needs of these breeding shorebirds.
If we needed any proof that our efforts were welcomed by the birds, it wasn’t long in coming – more than once, a mated pair of snowies started exploring our boot prints. One pair allowed the volunteers to get pretty close, then gave forth with some mating calls, and the male did a “rodent run” to impress his mate.
In three hours we had made a serious dent – actually thousands of them – in the flat surface of several ponds. We headed back to the parking lot and made quick work of two plates of Carleton’s homemade cookies, baked in his toaster oven!