Protecting Wildlife Corridors in Ventura County

1. What are wildlife corridors? 
2. Why are wildlife corridors important?
3. What are some of the species that benefit from wildlife corridor protections?
4. How can wildlife corridors be better protected?

Southern California has long been a biodiversity (a term that signifies species variability and variety of organisms) hotspot, but because of urban development and other factors during the past century, many ecosystems and wildlife have been increasingly impacted in negative ways. Highways, malls, housing developments, and more have all had significant consequences for native plants and animals living in the area.

Creating wildlife corridors for vegetation and wildlife to safely move between habitats that may have been divided because of urban development or other human-related activities will be able to provide an avenue for animals to travel safely, and for humans to live in harmony with them, providing benefits to both sides.

A wildlife corridor is a strip of habitat that has seen less significant development than surrounding areas and which connects wildlife populations that are separated by roads, buildings, agricultural land, and other infrastructure.

Altogether, the Los Padres National Forest, Angeles National Forest, and Santa Monica Mountains National Recreation Area support a wide variety of wildlife species.  ⁴   The Los Padres is home to at least 27 species protected under the Endangered Species Act, the largest amount compared to any other national forest in California. Iconic species such as mountain lions, black bears, and bobcats can be found in all of these areas, but they have serious issues moving from one place to another due to the heavily fragmented landscapes of Los Angeles and Ventura Counties.

Wildlife survival depends on movement, whether it is to look for shelter, find food, seasonal migrations, or to find mates. In order to preserve biodiversity, species must be able to move around for gene flow and change geographic locations if needed, especially regarding the effects of climate change.  ¹   The more development there is, the more likely species are to be isolated, putting them at risk of extinction because they are isolated from other populations.

Different species have varying needs for survival and thus will vary in their range of habitat as well as to what extent habitat fragmentation will affect them. Bigger mammals like mountain lions, bears, badgers, and bighorn sheep require a wider range of habitat, and are the most threatened by issues of habitat fragmentation.  ⁴   They may become lost if isolated due to urban development and encounter barriers for habitat access such as roads. In addition to habitat barriers, roads and highways also result in wildlife-vehicle collisions, noise and light pollution, unplanned human-caused fire ignitions, and the spread of non-native species. 

The South Coast Missing Linkages report offers a detailed plan for various wildlife corridors located along the California South Coast, complete with where habitat crossings are needed to maintain not just what we have left of the precious wildlife, but also clean air, water, and environment for human recreational activity.  ¹    This report was based on extensive research and collaboration with biologists, conservationists, planners, land managers, conservation organizations and groups and thorough GIS analyses, South Coast Missing Linkages has noted 109 focal species (including plants, insects, fish, amphibians, reptiles, birds, and mammals) that cover a wide range of habitat, ecosystem, and movement needs. Some examples of ecosystems that support focal wildlife species in the the Los Padres National Forest and Angeles National Forest include chaparral, coastal sage scrub, oak woodland, riparian woodlands, and even conifer forest (at higher elevations).  ⁴   

Additionally, a study conducted on the wildlife usage of highway under crossings in Southern California a decade ago has already demonstrated that wildlife do indeed regularly frequent the passages, including but not limited to large and medium-sized mammals such as deer, coyotes, and bobcats, and a single record of a mountain lion crossing through.  ⁴    Combining evidence of use of corridors along with the benefits of allowing species to traverse across their habitats demonstrates that establishing wildlife corridors will help increase diversity and better conserve plants and animals that may have been harmed by urban development, especially if it has already been proven that animals have been using the corridors since 2004. 

The linkage designs proposed in the South Coast Missing Linkages report aim to achieve the following: provide substantial habitat for species to continue gene flow, ensure key resource accessibility and natural processes, and allow enough space for wildlife to respond to any changes in climate, with a minimum width of two kilometers (1.2 miles).  ¹  

Over ten wildlife corridor connections were recommended in the South Coast Missing Linkages report, ranging from corridors connecting our local mountains to linkages along the U.S.-Mexico Border. These strategies have been applied to other states as well, such as Arizona. This plan is backed by the U.S. Forest Service, California State Parks, Conservation Biology Institute, South Coast Wildlands, and many other organizations dedicated to conserving wildlands and habitats.

In 2019, the Ventura County Board of Supervisors  adopted  new ordinances aimed at adding some additional layers of protection to the known wildlife corridors identified in the South Coast Missing Linkages Report where they intersect Ventura County. This was the result of several years of work by County staff, who conducted an immense amount of outreach with ranchers, farmers, and other landowners with properties in these corridor zones as well as conservation and wildlife protection organizations. In November of last year, the 2nd Appellate District of the California Courts of Appeal  upheld  these ordinances after years of being challenged by some industry groups.

The ordinances in Ventura County were a huge step in the right direction, and other counties will likely look at them as a model for adopting similar protections for wildlife corridors. So an important question to ask now is: are there ways that these corridors can be protected even further?

The existing wildlife corridor protections in Ventura County only apply to lands within the County of Ventura's jurisdiction, but the corridors themselves cross through incorporated cities that are not affected by the ordinances. In fact, some of the corridors are completely bisected by non-County lands within cities, which we refer to as chokepoints.

When Ventura County was in the process of adopting their wildlife corridor protection ordinances several years ago, many cities in the county signaled that they would implement something similar in order to protect these corridors where they cross city jurisdictional lands. However, none of the cities have fully followed the County's lead since the ordinances were established. Thousand Oaks, Camarillo, Simi Valley, and Moorpark all have an opportunity to implement essential wildlife corridor city ordinances to clear up the chokepoints identified above. This would not only help protect sensitive, threatened, and endangered species, but it would also help our communities better live with wildlife on these fragmented landscapes. And addressing these chokepoints is especially important now as other areas around the country look for tangible examples of how local governments can effectively implement wildlife corridor protections.

 ¹  South Coast Wildlands. 2008. South Coast Missing Linkages: A Wildland Network for the South Coast Ecoregion. Produced in cooperation with partners in the South Coast Missing Linkages Initiative. Available online at  http://www.scwildlands.org . 

 ²  Zellmer, Amanda J., and Barbara S. Goto. “Urban Wildlife Corridors: Building Bridges for Wildlife and People.” Frontiers in Sustainable Cities 4 (2022).  https://www.frontiersin.org/articles/10.3389/frsc.2022.954089 . 

 ³  Curtin, Susanna. “Wildlife Tourism: The Intangible, Psychological Benefits of Human–Wildlife Encounters.” Current Issues in Tourism 12, no. 5–6 (November 1, 2009): 451–74.  https://doi.org/10.1080/13683500903042857 . 

 ⁴  Ng, Sandra J, Jim W Dole, Raymond M Sauvajot, Seth P.D Riley, and Thomas J Valone. “Use of Highway Undercrossings by Wildlife in Southern California.” Biological Conservation 115, no. 3 (February 1, 2004): 499–507.  https://doi.org/10.1016/S0006-3207(03)00166-6 .