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>> We humans have a huge impact on our environment. We hear about a lot of things like Climate ChangeÉpollutionÉbut actually the most important influence that we have on our natural environment is by destroying that environment. Actual destruction and then the fragmenting of the parts that remain.

Roads are a classic example of the kinds influences that our society has that we don't typically think about on a regular basis. So if you pick any road next to your house and take 15 minutes and just sit there and count how many vehicles go by per day, it turns out that's a huge number. And you multiply the roads outside your house by the rest of the roads around the county, around your state, around your nation, etcetera, and you find that we've crisscrossed most of the civilized world with a huge network of roadways. For you and I roads can possibly be dangerous, but we rapidly learn as young children to be wary of these structures.

Not all animals have that ability or that luxury to learn as we do. So one of the projects that we're working on here at Cal State Channel Islands is an effort to document how intensive the death rate on these roads are for mobile animals, things like deer, things like coyotes, things like squirrels.

We do this by surveying the entire county and evaluating the number of individuals that die on each particular segment. We go out in cars and survey. We have one individual driving, someone else or a couple of other people observing from the passenger seats safely, and we go down and we drive roads and we look for road kill. When we see a road kill, we mark the location and we identify the species. Importantly, we also say when we don't see individuals killed. So that helps us create a much more accurate rate of the kills that happen along the road.

We survey a variety roads from small roads such as Latigo Canyon here in the Santa Monica's to relatively large roads such as the 126 right here between the 5 and Fillmore in the inland edge of Ventura County. To intermediate-sized roads, in this case the 23 through Grimes Canyon that has a relatively heavy vehicle load but very low road kill, presumably because there's not a lot of ideal habitat on either side of the road and the roads are very cliff-like. Coastal roads, such as Las Virgenes Canyon Road here approaching the Pacific Ocean. We also survey the periphery of the county including the very edge of the terrestrial environment, for example here along the Pacific Coast Highway in Malibu. You can imagine a small squirrel or deer or raccoon trying to get across a virtually impenetrable barrier like this. It's pretty much a death sentence if you try to.

Managing these landscapes is always challenging. Roads always grow. Their influences always expand. People are always wanting to do additional developments along the spine of a roadway.

Researchers that have looked at road kill have found disturbingly high levels of kills, and so much so that many people now believe that the deaths from cars exceed most all other, if not all other, sources of mortality for animals like deer. Here's some preliminary data so far from my research. On the left, a map of Ventura County. Areas that are within a hundred meters of a road are in yellow. Area within in five hundred meters of a road all in orange. And what you see is the vast majority of the area in the county is very close to one or more roads. On the right hand side, you'll see some preliminary data from last year which suggested that, give or take, we're killing something on the order of 5,000 large animals a year in the Santa Monica National Recreation Area; deer, bobcat, etcetera. County-wide, we're killing somewhere on the order of about 14,000 animals a year and that's probably conservative.

So the hope is that we can take this information, do things better, minimize accidents and minimize contacts with animals.


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