A report by the National Park Service and a nonprofit agency recommends methods and enhancements needed in local mountain areas to help maintain natural movement of wildlife between large habitat areas.
By Ward Lauren / Special to The Malibu Times
A “missing linkages” report designed to ensure the continued existence of wildlife indigenous to the Santa Monica/Sierra Madre mountains has been released by the National Park Service, in conjunction with the nonprofit South Coast Wildlands organization, to approximately 90 civic agencies, jurisdictions and public action groups focused on open space and wildlife habitat conservation.
The 213-page report, part of the South Coast Missing Linkages Project and titled “A Linkage Design for the Santa Monica-Sierra Madre Connection,” is an informational rather than an action document and is advisory in nature, Parks Service officials said. It recommends methods and enhancements for maintaining critical corridors, the “linkages”, that allow wildlife to move naturally between large habitat areas. The sector affecting Malibu specifically includes the Santa Monica Mountains, the Susana Hills, Simi Hills and north to the Los Padres National Forest.
Some of the recommendations include not only keeping open and maintaining wildlife corridors for mammals in urbanized areas to allow for migration, but to remove nonnative vegetation and to restore riparian vegetation in certain creeks and watershed areas that would inhibit the recovery of Southern steelhead trout and other species. Removal of barriers such as Arizona crossings (low-water concrete crossings) and dams, including the Rindge Dam in Malibu, is discussed as well.
“Their report addressed many species of plants, birds, reptiles, amphibians and mammals that live in the Santa Monica Mountains area,” said Kristeen Penrod, executive director South Coast Wildlife, which is headquartered in Idlewild in the San Jacinto Mountains. “The ‘focal species’ they concentrated on consisted of those sensitive to habitat loss and fragmentation caused by housing developments, roads and other barriers.”
South Coast Wildlife’s Web site listed some examples of focal species of the Santa Monica-Sierra Madre area and why they were chosen for study: “Badger have recently been sighted in the Santa Susan Pass; mule deer are utilizing an existing overpass to travel between the Simi Hills and Santa Susanas, and P2, a collared female mountain lion in the Santa Monica Mountains, has been sitting on a bluff overlooking Interstate 101 for long periods, with the Simi Hills on the other side.”
Also, “the critically endangered Southern steelhead trout was also chosen as a focal species to ensure watershed integrity. The steelhead population in Malibu Creek historically occupied spawning and rearing habitat as far upstream as East Las Virgenes Creek in the Simi Hills.”
The stimulus for the missing linkages project came from a workshop in 2002 sponsored by South Coast Wildlife, Penrod said. Featuring speakers from the National Park Service and other scientists, the meeting laid the biological basis for the project, to which experts from agencies such as the Santa Mountains Conservancy, the Nature Conservancy and California State Parks also contributed.
“The importance of this effort,” said Woody Smeck, superintendent of Santa Monica Mountains for the National Park Service, “is that in order to insure the persistence of survival of large mammals, in particular mountain lions, bobcats, coyotes and mule deer, we need to preserve these corridors that link the mountains to larger open space areas. This will allow the appropriate exchange of genetic material over time. The intermixing of gene pools is vital in preventing inbreeding within the populations of various species.”
While development and urban expansion present the most immediate concern in maintaining wildlife corridors, Smeck said, it is not development in general that is the problem. The government recognizes the value of continued growth for sustaining the economies and for other values. But growth can be shaped and planned strategically so that it occurs in a way that preserves linkages, he said.
“The good news is that these corridors are already in existence, and, for the most part, those identified in the report represent areas that are already undeveloped. The important thing now is to ensure that the development that occurs in these critical areas is done appropriately, that the developers keep in mind the importance of preserving the corridors. This is what the report is all about.”
An example of the effectiveness of the report that is already being felt, Penrod said, is the work now being done by the California Department of Transportation on some existing freeways that form barriers to animals.
“Caltrans is already working to improve wildlife access across the 118 [Freeway], and soon will [do so] on the 101 [Freeway],” she said. “Existing structures that animals use include box culverts, ditch culverts and bridges. Some bridges are for cars to use, but animals are using them, too. Caltrans has agreed to maintain these existing structures and plan for others where they’re needed in the future.”
More information on South Coast Wildlife and Project Missing Linkages can be obtained on the organization’s Web site, www.scwildlands.org.