It’s not every day you meet a snake charmer.

Well, technically speaking, Patrick Lien is a “snake researcher” with the U.S. Geologic Survey (USGS). I met Patrick earlier this spring at POST-protected Cloverdale Coastal Ranches, 6,857 acres of coastal plain south of Half Moon Bay. I was there to learn about his work studying the San Francisco garter snake and, if possible, to get up close with a few of these beautiful serpents.

The San Francisco garter snake is arguably one of the most endangered snakes in North America.

All of the known populations of this amazingly colored snake exist within San Mateo County. And for the past eight years, Patrick has been studying these snakes on our Cloverdale property to monitor the health of the population. I was excited to meet him and hopefully see, firsthand, one of the most endangered species on the continent. Well, given how rare these snakes are, we were both quite surprised at what we found that day (him maybe even more than me).

Watch this video and see for yourself:

Our interest in Patrick’s work began after reading the recent reports from USGS on the health of the San Francisco garter snake populations at both Cloverdale and Mindego Hill – another POST-protected property. This research measured the population size at these preserves with the goal of getting a pulse on the health of this endangered species.

Patrick Lien - USGS
Patrick Lien is a wildlife researcher with the USGS and has been studying the endangered San Francisco garter snake for the past eight years. He’s optimistic in regards to the current health of the population. Photo: Matt Dolkas, 2018

The results from this research were of particular interest given our recent restoration of the small ponds at Cloverdale. These ponds are the preferred habitat for the San Francisco garter snake as well as the endangered red-legged frog (one of their primary prey species). So we were excited to see what Patrick and his team had learned about the health of this snake’s population and see if our efforts had delivered any success.

What did they find? Good news! While the relative abundance of snakes fluctuated throughout the four-year study, the population has remained stable. And the ratio between males and females was also consistent with a healthy population. So, for now, things are looking good for the San Francisco garter snake.

But we’re not done fighting for their survival. Population stability for an endangered species is encouraging, but when a population is this small, it requires constant monitoring – something that, with the help of our partners, we plan to continue.

At the end of my visit with Patrick, we were reflecting on what has changed at Cloverdale since he first began his research there over eight years ago. While much has changed, a great deal is also the same. He was especially grateful towards POST, knowing that without our intervention, this land could have easily been subdivided and developed. I left that evening with a sense of peace, knowing that the beautiful snake we found was out there somewhere and that Patrick and his colleagues would be there to look after it.

About Post

Peninsula Open Space Trust (POST) protects open space on the Peninsula and in the South Bay for the benefit of all. Since its founding in 1977, POST has been responsible for saving more than 87,000 acres as permanently protected land in San Mateo, Santa Clara and Santa Cruz counties. Learn more

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