Lea este artículo en español aquí.
Green Foothills, an organization dedicated to preserving open space and farmland in San Mateo, San Benito and Santa Clara counties, held a forum Aug. 21 to pose a simple question: How did the mountain lion cross the road? According to the speakers, the answer is that in many places in California, it can’t—unless it has some help.
According to a California Department of Fish and Wildlife report, Restoring California’s Wildlife Connectivity 2022, 61 barriers to wildlife movement within California were identified in 2020 as high-priority sites for some form of crossing. One is at the eucalyptus grove near Rocks Road, south of San Juan Bautista on Hwy 101.
“We know that wildlife moves between habitats for a variety of reasons, such as breeding or seasonal migration,” said Caltrans Environmental Program Manager Morgan Robertson. “But roads and highways that run between habitats sometimes block wildlife movement.”
According to Zach Mills, a California Department of Fish and Wildlife field biologist, the main drivers of migration are intrinsic factors such as food and water, and extrinsic factors such as fires and environmental change.
The research uses tracking devices equipped with tri-axial accelerometers that are sensitive enough to detect when an animal, such as a mountain lion, tilts its head to drink from a water source. These devices also reveal when an animal has died.
“A collar sends a signal based on our programming to a satellite that dumps it onto our computer,” he said. “We can follow everything that comes from it. If the accelerometer stops in a certain position, we can respond very quickly to understand why that animal passed away and what happened.”
Data from the collars clearly show that Hwy 101 prevents mountain lions in the Rocks Ranch area from migrating north.
Obstacles such as the highway keep the animals from their natural hunting ranges or migrations, leading to inbreeding and genetic defects that can cause a species to die out. Mills said this was a difficult concept to articulate to the general public, which might think a species is genetically sound because it appears abundant.
“There might be 500 animals,” he said, “and that might seem like a lot. But all the genetic material might have come from two or three ancestors. Variation allows the species to persist long-term to sustain the next disease outbreak, the next fire, the next whatever.”
Mills said the bottom line is that freeway crossings facilitate the genetic exchange necessary for species’ survival. Without it, some species will face extinction within 50 years.
Robertson said that there had been an increase in wildlife-vehicle collisions in the Rocks Road area that a land bridge would prevent.
National Wildlife Federation statistics show that vehicle collisions are the No. 1 cause of death for many wildlife species, killing more than a million animals in the U.S. every day. Their studies show over 2 million accidents a year involve large wildlife, causing more than 26,000 human injuries or fatalities and $10.7 billion in medical costs and vehicle repair.
According to Conservation Project Manager Mark Bibbo of the Land Trust of Santa Cruz County, Caltrans has received a $6 million grant from the Wildlife Conservation Board to conduct studies and secure permits for the Rocks Road crossing. The crossing, which will require private and state funding, is estimated to cost $50 million and could be completed within 10 years.
“The Wallis Annenberg Wildlife Crossing in the Santa Monica Mountains hinted at the model for it,” he said. “It will be a while before it is built, but we have a lot of momentum towards it. So we’re just trying to keep that momentum going.”
The Annenberg Crossing, a 210-foot-long vegetated bridge made from 85 concrete beams, is scheduled to open in early 2026. More than $92 million—including $58 million in state funds and a $10 million grant from the Annenberg Foundation—was raised for the project, part of Gov. Gavin Newsom’s 30×30 Initiative, which seeks to conserve 30% of lands and coastal waters by 2030.
We need your help. Support local, nonprofit news! BenitoLink is a nonprofit news website that reports on San Benito County. Our team is committed to this community and providing essential, accurate information to our fellow residents. It is expensive to produce local news and community support is what keeps the news flowing. Please consider supporting BenitoLink, San Benito County’s public service, nonprofit news.
The post Planning begins on Hwy 101 wildlife crossing appeared first on BenitoLink.