Sean Manion

Earlier this month Point Mugu State Park was closed for two days while officials searched in vain for a mountain lion that had approached hikers in the Santa Monica Mountains. A day later, police officers were forced to kill a different mountain lion in a Santa Paula neighborhood.

When mountain lions show up in places where they usually do not, a flood of newspaper and television reports often follows. In these stories, lions are often represented as a single, scary species. Meanwhile, the relationship between lions and the environment is rarely mentioned.

To shed more light on this subject, The Times turned to Sean Manion, a conservation biologist and research director with the Resource Conservation District (RCD) of the Santa Monica Mountains. Manion’s expertise is biodiversity, particularly in the Santa Monicas, where he lives and works.

Manion, 47, grew up in the Pacific Palisades, just eight doors from the end of his street and the beginning of the wilderness. He spent much of his youth hiking and camping in the mountains, bringing home his first live snake when he was 5 and seeing his first mountain lion when he was 15. It was, and still is, the only lion he has seen in the Santa Monicas.

Manion earned his bachelor’s degree in anthropology and biology from the University of Arizona in 1975 and later earned a master’s in geography from Cal State Northridge. He has worked for the RCD since 1986. His work has concentrated on wildlife ecology, the natural history of various species and the preservation of biodiversity within the Santa Monicas.

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Question: There are always people who seem surprised when mountain lions show up in populated areas. Should they be?

Answer: What’s interesting about the Santa Monica Mountains and, generally, the western United States is that there’s still a lot of public land left. And, on that land, we are lucky enough to still have most of our native biodiversity intact, including a few mountain lions left in the Santa Monica Mountains.

But we’re reaching that thin line where we are going to start getting more extinctions with more roads and subdivisions in the mountains. Since the 1970s, the road density in the Santa Monicas has more than doubled.

Q: How many mountain lions are there in the Santa Monicas?

A: Probably between five and 10.

Q: How do you get that number?

A: That’s the big question. It’s an educated guess, based on my knowledge of lion home range and habitat, prey availability and comparing my estimates to the estimates of other ecologists in the mountains.

With all the research that has been done on mountain lions, population is the first, most basic question, and no one can answer it. They can just kind of make a guess because mountain lions are difficult animals to get numbers for.

When you see an estimate from the state Department of Fish and Game or from an environmental group, it’s an educated guess. The problem is once those numbers get in print, they often get published enough so that it becomes the new reality, when it’s anything but.

Q: If your estimate is in the ballpark, what does that say about the quality of the habitat in the Santa Monicas?

A: The habitat that exists now is generally in really good condition, despite the lack of an ecologically based fire management system and habitat fragmentation caused by development.

However, there are certain species, such as mountain lions, that need really large unbroken blocks of natural habitat. And they have been rapidly losing that in the Santa Monicas, as well as Southern California.

We’re also cutting off the habitat corridors and linkages to other mountain ranges and corridors, allowing lions to migrate and maintain a genetically viable population. So, in the Santa Monicas, the population of lions is in extreme jeopardy.

Another problem I foresee is that mule deer populations will continue to decline throughout the West because development is disrupting the migration pattern of deer between their summer and winter ranges.

Since mule deer are the primary prey of mountain lions, that in turn is going to make it difficult for lion populations.

Q: How do you reconcile that with the fact many people believe the mountain lion population has skyrocketed since the 1972 hunting ban?

A: There’s a popular perception, promulgated by whoever or what group, that the population of mountain lions will explode out of control. That’s just not the case, because mountain lions are regulated by prey availability, amount of space and by their social structure.

There will never be many mountain lions in the Santa Monicas because the Santa Monicas are 47 miles long and average seven miles in width. If the habitat exists, the lions will saturate the range as much as they naturally can. But that’s not overcrowding.

Q: Many people like the idea of wilderness until it shows up in their backyard and eats their poodle. Do people need to be better informed of what’s out there?

A: A lot of these planned or gated communities in and around the mountains are built with the idea of insulating people from the environment as well as other humans--instead of trying to coexist and understand the world around them. It’s the responsibility of those who live close to wildlife habitat to inform themselves on the local wildlife and what they can do to maintain a relationship with it.

Q: Do you think reducing the number of mountain lions, whether through hunting or some other management program, would have any impact on public safety?

A: No. All of the research indicates there is no relationship between hunting lions and the number of attacks on people. The area with the highest amount of mountain lion attacks on humans is British Columbia and hunting has been permitted there for years.

Q: Grizzly bears once lived in the Santa Monicas. What was the effect of taking them out of the ecosystem?

A: I can only speculate. Something that has always interested me is the relationship between grizzlies and the steelhead trout. There were once runs of steelhead in Southern California, and we know that grizzlies eat salmon. So that’s a lot of protein being moved up a stream at certain times of year. When that protein is removed, a lot of energy is removed from the ecosystem too.

I also wonder if bears were instrumental in opening some major-league trails through the mountains. The chaparral here is very dense. A human can’t just walk through it. Maybe these trails opened up certain patches of habitat to sunlight and wind; that created certain microclimate regimes and, therefore, forever changed the natural and ecological processes in the mountains. But this is only speculation. I can’t really answer your question.

Q: What happens to the environment if we remove mountain lions from it?

A: One of the things that both does and does not amaze me is that people say, “What do we need biodiversity for?”

For example, 90% of our medicines come from species of plants or animals. Biodiversity of native species isn’t just important because it is nice to look at, but because it is completely, unequivocally, essentially linked to the survival of the human species. There are so many linkages in the natural world that if we destroy native biodiversity we literally do not know what we are losing.

An example: One of the things mountain lions do is prey on deer and elk. There are times of the year when deer and elk herd. Mountain lions, by preying on deer and elk, move those herds around, which keeps them from overgrazing parts of their watershed. If you overgraze, you lose topsoil, which causes sedimentation in streams, which means plants don’t grow back as well as they did before. And that’s just one linkage.

When it comes to preserving native biodiversity, the quote I always come back to comes from [conservationist] Aldo Leopold. He said the first rule of intelligent tinkering is to keep all the parts.