Article

By Bridget Lyons

November 19, 2024—How do you sell out the 650-seat Rio Theater in Santa Cruz?

With good environmental news. And boy, do we need that.

On Saturday, Nov. 10, just a few days after an election that will likely result in serious setbacks for conservation efforts of every kind, the Land Trust of Santa Cruz County celebrated an unequivocal win for humans and nonhumans alike: the success of the Highway 17 Wildlife Crossing at Laurel Curve.

For those of you unfamiliar with the backstory here: The Land Trust began looking into the roadkill problem on the popular commuter route between San Jose and Santa Cruz 20 years ago. Among their findings was an alarming statistic. Between 2013 and 2017, there were 77 documented incidents of animal/vehicle collisions—34 of which occurred at Laurel Curve, a spot about a mile south of Summit Road, where Laurel Drive intersects Highway 17. It quickly began to look like building the Bay Area’s first wildlife crossing might be the solution.

Ten years of research, observation, and heavy-duty fundraising—both to purchase the land and easements on either side of the crossing and to pay for the structure itself—ensued.

Partnerships were built with Caltrans, the Santa Cruz County Regional Transportation Commission, the Wildlife Conservation Board, and the California Department of Fish and Wildlife, all critical stakeholders in the process.

To make a long story short, a lot of hard work by a lot of people resulted in the opening of what’s called a “box culvert”—essentially an undercrossing—in January of 2023. A bobcat was caught on video using it the same day the cameras were set up.

Fast forward to February 2024, one year after the crossing’s opening, and you’ve got
these user statistics:

• 864 black-tailed deer
• 56 gray foxes
• 7 bobcats
• 4 mountain lions
• 2 opossums
• 1 skunk
• 1 animal/vehicle collision

That’s more than 900 animals that weren’t killed by any of the 65,000 vehicles per day that travel Highway 17. That’s also more than 900 vehicle-driving humans who didn’t have to risk their lives and the lives of other drivers by swerving, braking, and possibly having an accident on a busy road.

A Good Show

Tanya Diamond and Ahíga Snyder, the folks behind Pathways for Wildlife (the organization tasked with the surveying and monitoring efforts before, during, and after the crossing’s construction), entranced the Rio Theater full house by playing video clips of creatures who have used the Laurel Curve underpass.

We watched male mountain lions stride regally right down the middle of the tunnel. We saw skittish gray foxes prefer a higher, tighter passage at the structure’s edge that enables them to keep a watchful eye on possible predator traffic in the main corridor. We marveled at bobcats marking territory and bucks escorting fawns into new terrain.

In short, we had the chance to observe animals making this human-made structure part of their geographical reality and incorporating it into their movement patterns. We witnessed adaptation in action.

In addition to saving animal and human lives in the short term, the Laurel Curve Wildlife Crossing is contributing to a longer-term effort as well: a much-needed increase in habitat connectivity and genetic diversity for the animals of the Santa Cruz Mountains.

As Sarah Newkirk, Executive Director of the Land Trust explained, “Roads connect us, but they isolate wildlife from each other.” They create rigid barriers to animal movement, effectively creating de facto population islands. Animals in these areas become inbred, and it’s well established that an ongoing lack of genetic diversity is a recipe for eventual extinction.

Mountain lions require especially large ranges to maintain genetic diversity. Being apex predators, there aren’t many of them (an estimated 50-60 total live in the Santa Cruz Mountains). Their capacity to travel large distances enables them to interbreed with animals from other regional populations—if they can get to them.

To illustrate the way in which roads can impede this access, Dr. Christopher Wilmers of UCSC and the Santa Cruz Puma Project recounted the tale of radiocollared mountain lions 16M (a male) and 18F (a female) whose movements he and his associates studied carefully. “For a while, 16M’s track was looking pretty typical. He was spending most of his time on the northwest side of Highway 17,” Wilmers began. But then his team noticed that 16M began crossing the busy road repeatedly—at Laurel Curve—to access its southeastern side. Who was there?

18F, of course, and locational data showed the pair walking overlapping paths. Shortly after these presumably romantic mountain lion rendezvous occurred, Wilmers and his crew saw 16M’s movements slow down significantly and wondered if the big cat was sick or injured. Eventually he was caught on camera with a large open wound on his flank, most likely from a vehicle collision. Sadly, he died soon after. 18F died a few months later as well. “She had a fetus in her womb,” Wilmers said, and I felt the crowd gasp.

This tragic story made the need for a safe wildlife crossing even more apparent, as did Wilmers’ team’s discovery of kinked tails and malformed sperm—signs of genetic inbreeding—in the local puma population.

Fortunately, the descendants of these mountain lions have a viable Highway 17 crossing option today—and the fact that they are using it is what all of us were there to celebrate and watch on the big screen.

Of course, the work isn’t over yet, as there are other roads that block animal movement. The one most on the minds of the Land Trust staff these days is Highway 101. They recently acquired a parcel of land, called Rocks Ranch, which could be home to an ideal crossing site (see the Hilltromper article “Wildlife Crossing to Safety” for more information about this project).

The Land Trust of Santa Cruz County hopes to repeat its winning recipe of solid research, stakeholder collaboration, and broad fundraising efforts to facilitate a wildlife overpass there by 2032. In addition, the Midpeninsula Open Space District is planning to unveil a crossing near Lexington Reservoir in 2028. And, further afield, the Liberty Canyon Wildlife Crossing north of Los Angeles is slated to open in early 2026.

There’s no question that these efforts are expensive and time consuming. There’s also no question that they are highly effective ways to ease human impacts on the nonhuman creatures with whom we share space. We are building them, and the animals are coming. This is good news—and a good reminder for those of us who like to tromp around in wild spaces that our support for these efforts is critical to keeping them wild.

Bridget Lyons is a writer and editor living in Santa Cruz. To learn more about her work and explorations, visit www.bridgetalyons.com.