Wildlife-Friendly Fencing

By Nancy Reyering, Board Member

The San Francisco Bay Area is one of the most diverse and important ecosystems on earth. Our biodiversity hotspot is the only home for numerous species that are at great risk from human impacts. Expansion of developed areas contributes to habitat loss for both plants and animals. Along the Peninsula, expanding development areas, commercial farming industries, and population pressures contribute to habitat loss for both plant and animals. Much of our wildlife is forced into the margins.

Animals like the fox, bobcat, deer, and mountain lion take many paths to navigate this semi-urban landscape. According to the Urban Wildlife Research Project, animals use creeks as a primary transportation node between the mountains and the Bay. But when you track individual animals’ paths across this creek-side wildlife corridor, you find a much more harrowing journey: animals consistently navigate backyards, culverts, drainage ditches, busy freeways, and barbed wire fences. However, impassible property fences in semi-rural areas often divert wildlife into busy streets and unsafe urban areas. Rural and semi-rural residents can help these animals stay safely in wilderness areas by using wildlife-friendly fencing on their properties to improve animal crossings.

Several peninsula towns, including Woodside and Portola Valley, serve as “buffer zones” between wilderness and suburbia, and are situated squarely in the last remaining habitat for threatened wildlife. Because habitat cannot exist as “islands,” one of the most important ways residents of these semi-rural areas can live in harmony with wildlife is by designing fencing that permits animals to jump over, climb over, or pass through. Especially important on larger properties, wildlife-friendly fencing allows wildlife to traverse property lines, have access to creeks and forage sources, and keep wildlife where they belong: away from the building envelope and off the roads. The goal is not to eliminate fencing, but to use it appropriately. For example, rather than fencing in an entire property’s borders, it is more appropriate to focus on deterrent fencing—high and sturdy fences around gardens, livestock, and other sensitive areas that prevent predators or garden plunderers from getting in.

Admittedly, it can be daunting to imagine a large predator like a mountain lion or coyote in your backyard. Smaller mammals like bobcats and raccoons, which can harm house pets or chickens, may also give pause. Deterrent fencing can keep pets and livestock safe, while larger property boundaries can remain open to wildlife in order to provide safe and efficient crossing to wilderness areas that serve as more appropriate food and water sources.

By giving animals access to creeks and riparian corridors, they find both food and water away from residential habitation. When wildlife is prevented from accessing their natural habitat, they become stranded on islands, including roadways. Young deer become separated from their mothers; foxes lose access to their nesting places; even quail can have difficulty raising their young when their habitats are fractured.

We need to provide connectivity throughout our communities to create sustainable habitat for wildlife. When we incorporate “smart fencing” strategies, and refrain from surrounding large properties with impermeable fencing, we allow our wildlife to move naturally, find forage, raise their young—and leave us undisturbed.