One of the main goals of the NCOS restoration project is to enhance habitats that support a broad range and diversity of wildlife. The restoration plan includes features designed to benefit groups of wildlife such as birds and reptiles, as well as features designed specifically for important endangered species.
A significant part of the restoration project is the expansion of estuarine wetlands, which are beneficial for shorebirds, waterfowl and wading birds, as well as some fish and amphibians. A variety of water levels and salinities will create a mix of niches suitable for different migratory and resident bird species, and the creation of a number of pools will provide refuge for fish, particularly the endangered Tidewater Goby (see map of refuge pools below). Devereux Slough is an intermittently tidal estuary, which means that one to a few times per year, after large rain events or high surf and tide events, the beach berm at the mouth of the slough breaches and most of the water in the slough drains out into the sea in a few hours. The pools and refugia that will lie behind peninsulas in the restored NCOS site will allow endangered gobies and other fish to avoid being washed out to sea during these breach events.
Map of NCOS restoration site showing location of pools and refugia for Tidewater Goby.
Another key species that the NCOS restoration project will support is the Western Snowy Plover, a threatened shorebird. Careful monitoring by Coal Oil Point Reserve has revealed that this species is as succesful nesting on a sand bar along the northern edge of the existing Devereux Slough, just south of the Venoco access road, as they are on the beach. The NCOS project will create a 2.5 acre sandy area on the north side of the access road that will mimic the conditions that currently support nesting on the south side of the road. These inland nesting areas may become more important in the future under projected sea level rise conditions.
Map of NCOS restoration plan with snowy plover nesting area, and picture of sand collection from NCOS site for the snowy plover area.
Other wildlife habitat features in the restoration project design will be made from salvaged materials. The main trunks from the majority of the trees that were removed have been saved to be used as perches for birds and squirrels, and provide other habitat features in the restored landscape. We will drill a variety of holes into these logs to help support a range of solitary nesting bees as well as beetles that make their homes in old logs and under bark. Woodchips from the smaller branches will be incorporated into the restoration project as a way to retain soil moisture and re-incorporate organic matter. In addition, piles of brush will be placed around the landscape to serve as intermediate cover areas for rabbits and squirrels until the restored vegetation provides that cover naturally. The California Native Plant society special status species, Southern Tarplant, forms excellent brush piles with nutrient rich seeds and prickly stems that help protect smaller animals from larger predators. Conversely, areas of compacted and stable bare ground can provide important open spaces that are excellent for ground nesting bees and foraging by a variety of seed and insect-eating birds and lizards.
Stockpile of tree trunks and willow branches salvaged for creation of habitat features on NCOS.
Newly graded restoration sites lack hideaways that naturally develop in an area over time and can be important habitat for some reptiles, amphibians and small mammals. The NCOS project includes a habitat feature known as a "hibernaculum" to help provide that support. These semi-subterranean features have narrow entrances into a multi-layered underground habitat with a pipe feature that connects the surface to a water reservoir below ground. All around the restoration site, 2 to 4 foot deep holes will be dug and filled with carefully arranged "urbanite" (concrete, wood, tiles, and pipes) and covered with wood chips and soil to create a zone that is thermally stable and inaccessible to predators like skunks, raccoons and hawks. Species that particularly benefit from these features include field mice, snakes, lizards and salamanders, as well as a diversity of insects. The project site will also include burrows for burrowing owls on mounds within the restored grassland, adjacent to the vernal pools, which may enable that species to return to the site.
Hibernaculum construction: pipe supplies water to underground reservoir, and "urbanite" material provides many layers and spaces.
Hibernaculum covered with boulders, twigs, soil and mulch; multiple small entrances keep large predators out.
By incorporating these features into the restored landscape, we will help support the food web from the bottom up: the restoration of native plant communities will provide food and other resources; the creation of various refugia will provide shelter and nesting habitat for invertebrates, small mammals, reptiles and amphibians; and the perches will give hawks, kestrels and other species access to prey and opportunities to display their breeding plumage.