Keeping them apart is Interstate 5, a major freeway that cuts across the Olympic peninsula, where cougars have lower genetic diversity than in the rest of Washington state.
"We know I-5 is a barrier and something needs to be done about it, but we are so early in this process."
Glen Kalisz is a habitat connectivity biologist with the Washington Department of Transportation. He's part of the Olympic Cougar Project, which has been tracking, tranquilizing and fitting cougars with GPS collars to assess where they go and why, with the goal of connecting cougar populations on the peninsula to the rest of the state.
"We're in this information gathering phase and we need to collect information from wildlife cameras and from GPS collars that the Olympic Cougar Project is putting out on dispersing animals like cougars that are going to act as like an umbrella species. And then they're going to tell us connectivity needs across the I-5 and, but the answer is, I think, my opinion, wildlife crossing structures... these wildlife crossing structures are very effective at bridging habitats if they're built effectively, if they're built correctly, if they're built in ways that species find them attractive and if they're put in areas that species are or tend to move."
In Southern California, transit authorities are soon to break ground on a wildlife crossing over U.S. Highway 101, in one of the last remaining areas where there is natural habitat on both sides of the freeway.
Seth Riley, a wildlife ecologist with the U.S. National Park Service, says that wildlife crossings also improve the broader ecosystem.
"I mean, the other thing about mountain lions is they're really the one species that serves that role of being the apex predator. They're really the species that is a significant predator on deer, for example. That's their main prey, like 90 percent of the kills that we find are deer. And so, you know, we don't know exactly all the things that could happen if we lose mountain lions, say, in the Santa Monica Mountains, but the truth is: that's the only species in that role and we don't want to do that experiment... if one day we don't have about lions anymore in this place, I mean, you know, I think that really will be a sad day."
