A wildlife corridor is a continuous thread of habitat that connects species of animals that may have been separated by roads, housing developments or other human activities.

These animal corridors are important because they allow different populations of animals to inter-breed, which gives them genetic diversity. It also allows access to more areas of habitat so predators can follow sources of food.

Animals trapped within smaller habitats that do not have access to additional habitat areas might inter-breed and suffer from genetic disintegration. Eventually, if they are not allowed to migrate, the species within an enclosed habitat will disappear.

Let me give you an example. A male mountain lion needs 100 miles of continuous habitat for himself. A female mountain lion needs 50 miles of continuous habitat. That is 150 miles of habitat for two cats.

When the male and female have a kitten, that kitten needs to migrate out of its parents areas and find its own territory. If it is cut off from other habitats, it cannot disperse, and the male (its own father) will probably kill it. If the offspring is a female, her father might mate with her. Over time, the progeny from this union will suffer genetically, and the mountain lions will die out in this area.

To state this even more simply, imagine you were walking down a trail and a large tree fell down in front of you, blocking your way. Imagine there were no passage around the tree. This is what a large animal experiences when its historical crossings are blocked by a freeway or a new housing development.

The animal must try to find a way around the blocked area to maintain the integrity of his genes, to find a mate, and to eat.  The animal might try to cross a road. Recently we saw a mountain lion death in Santa Clarita. The animal was trying to cross the road and the driver could not stop in time. This has also recently happened on Mulholland Highway. Another dispersing mountain lion was killed on Interstate 5 at Calgrove.  Unfortunately, roads are not always safe corridors for animals.

Freeways, roads and housing developments are not the only things that can block animal corridors. Even in rural areas, people might feel the need to fence off their property completely. If everyone puts high fences around lots of acreage, the animals cannot pass through. As urban sprawl takes over, the animals have less and less room to roam.

Some of you might not care that a mountain lion was killed, or that there are approximately three (3) left in our local mountains. The consequences of losing such a great predator could be many.

Mountain lions eat an average of 1.5 deer per week. This is why a male needs 100 square miles to roam. He moves around so he does not deplete the deer population, and he follows herds of deer around his territory.

If there were no mountain lions, there would be a huge overpopulation of deer, rabbits and other rodents. The deer might be in your yard eating all of your flowers and grass. The same would be true for the rabbits. The mice and rats might invade your house and gather meals in your pantry. This would be especially prevalent in years of drought when wild foods could no longer sustain large populations. We’ve seen this happen on the East Coast where yards have been invaded by hundreds of deer at a time.

Southern California Wildlands, along with the Mountains, Recreation and Conservation Authority, The Nature Conservancy and Caltrans have been looking for solutions to this problem. They have identified crucial animal corridors and have proposed ways to keep these critical habitat areas open.

Caltrans has been researching ways to go under or over freeways to give the animals a safe way to cross and open up good habitat that exists on both sides of the roadways. The Nature Conservancy, MRCA and S.C. Wildlands have been acquiring property which will remain wild and will assist these animals before it is too late.

We are lucky in California to have some nice core habitat left. Animal corridors can connect these large areas of habitat and assure the survival of many of our indigenous species.

Key species include mountain lions and black bear. Coyote, fox and a multitude of smaller species such as skunk and raccoon that might take a little longer to migrate into new habitat will also be able to use the corridors, and a new gene pool will guarantee their survival.

The bottom line is maintaining what we have and adding a few crucial pieces such as vegetated crossings over freeways to complete the puzzle. By keeping these areas open, our ecosystem will remain healthy, our species will survive, and we will improve our quality of life, as well.

Dianne Erskine-Hellrigel is executive director of the Community Hiking Club and president of the Santa Clara River Watershed Conservancy.