A busy stretch of road that runs along San Pablo Bay just south of Sonoma Raceway is considered a hot spot for roadkill.
Highway 37, which connects Novato to Vallejo, slices right through major habitat for jackrabbits, deer, coyotes, bobcats and mountain lions. The high speed limit and heavy congestion makes the four-lane highway an extreme peril for animals wanting to cross.
“For animals, it’s bad news,” said Fraser Shilling, co-director of the UC Davis Road Ecology Center.
With wetland restoration going on at Sears Point, he said, more animals will be drawn to cross the highway to get to the newly restored marshes to the south for food and habitat. They currently don’t have much of an option except bolting across the road, where an average of 37,000 vehicles travel a day, Caltrans said.
“A road like that with that much traffic makes it difficult for animals to move,” said Julian Meisler, baylands program manager with the Sonoma Land Trust.
The Land Trust is working on creating a safer wildlife passage under the highway. It has teamed up with groups such as the San Pablo Bay National Wildlife Refuge and Point Blue Conservation Science’s Students and Teachers Restoring a Watershed program, known as STRAW, to restore the creek that flows through a decades-old cattle underpass. They’re planting willows, oaks, coyote brush and other plants to make the culvert more attractive for wildlife to use.
Animals avoided the underpass, about three-quarters of a mile west of the intersection of Highways 37 and 121, because of the lack of trees and shrubs to serve as cover, said Don Brubaker, manager of the wildlife refuge, which owns and manages the land to the south of the highway.
“We need to advertise this as a way to go (across) that wildlife understand,” Brubaker said, adding the best way to do so is by creating desirable habitat for animals.
“There is the potential for animals to be moving from Tolay Lake Regional Park down to the marsh,” Meisler added. “It’s really a disconnected landscape right now.”
He said the project will expand the animals’ range. The Land Trust placed a camera at the underpass a few months ago to see what animals were moving through the area. So far, it captured coyotes and jackrabbits.
Once they add more plant coverage, wildlife experts say, they may find more bobcats, deer and mountain lions roaming the area.
“By putting more plants there, they have more choices for cover, more choices for shade and more choices for food,” said STRAW restoration manager John Parodi, who called the underpass a critical piece for the movement of animals.
“Highway 37 is a bottleneck for wildlife,” he said.
More than 250 Petaluma and Novato students involved in his program have helped plant nearly 500 trees and shrubs, including coast live oak, valley oak and California buckeye, Parodi said.
The cattle underpass was built in the 1920s, according to Caltrans spokesman Allyn Amsk. He said the agency had to repair the culvert and cattle crossing last year after it previously filled with debris and flooded, damaging the foundation. Caltrans workers replaced the eroded section, put in a new concrete floor and made repairs to the damaged highway above, costing around $500,000, Amsk said.