Cal Poly Snake Researchers Examine Rare Find in SLO County

Biological Sciences Professor Emily Taylor and her students examined a live rubber boa snake found at Montaña de Oro State Park and collected data to send to the California Conservation Genomics Project. 

September 2025 / NEWS STORY
by Nick Wilson

Over the past 15 years, Cal Poly biological sciences Professor Emily Taylor had heard about sightings and seen photos snapped by hikers of elusive rubber boa snakes along the Central Coast.

But for the first time, Taylor and her students recently had the opportunity to see a live rubber boa up close and gather useful data after local environmental consultant and snake enthusiast, Ken Wimer, came across a sizable yellow-green rubber boa in mid-August.

The rubber boa is a relatively small boa species with loose and wrinkled skin that has a rubber-like appearance.

More commonly spotted in California natural environments to the north and south of San Luis Obispo County, Taylor and her students have long hoped to come across a rubber boa in local natural settings.

The northern rubber boa can be found in parts of Northern California, such as Santa Cruz and the Sierra Nevada. The southern rubber boa inhabits places in Southern California, including east of Los Angeles in the San Bernardino area and the San Jacinto Mountains.

“For years, we've been just trying to get our hands on one, and we hadn't, but we knew they were there because very occasionally somebody will find one, and people spend a lot of time looking,” Taylor said.

Last year, Taylor was alerted to a dead rubber boa, likely run over by a mountain bike on a trail, spotted by the husband of a volunteer and donor to her Project RattleCam initiative. She collected the first rubber boa DNA along the Central Coast from that snake.

Then in August, Wimer discovered a rather large, live rubber boa in the middle of a hiking trail in Montaña de Oro state park near Los Osos.

One of Taylor’s undergraduate biology students, a friend of Wimer’s, called her to let her know about the rare find and wanted to know if Taylor was interested in seeing it. The answer was a resounding “yes.”

Working with John Sayers, a SLO County-based California State Parks environmental scientist, Taylor quickly arranged for Wimer to bring the rubber boa to campus.

A closeup of the belly of a rubber boa found in
August at Montaña de Oro State Park.

“My two Frost research program students, Ethan Barnes and Grace CadwalladerOlsker, took data, weighed and measured it, and I took a DNA sample,” Taylor said. “We then sent a DNA sample to UCLA and returned the snake back to its natural environment.”

The docile creature was “the biggest rubber boa that I've ever seen in my entire life,” Taylor said.

Because of its relatively large size, roughly 20 inches long, Taylor believes it was a northern rubber boa.

The data collected by the Cal Poly snake researchers will help other scientists better understand the rubber boa’s biogeographic history, involving the study of how the distributions of organisms across the earth have changed over time.

The California Conservation Genomics Project (CCGP), led by UCLA professor Brad Shaffer, is a state-funded initiative to produce a comprehensive, multispecies, genomic dataset to help manage regional biodiversity.

“This all happened during the last week of the students’ Frost summer research project, and the students were excited to help when it came into the lab,” Taylor said.

An interesting fact about this snake is that they have a rounded, blunt tail, which is unusual for a California snake. Most California snakes have pointed tails. Besides releasing a musky smell to deter predators, when the rubber boa is disturbed, it will hide its head and stick the rounded tail up to make it look like it’s the head.

“A predator will go for the tail instead of the head,” Taylor said. “And this particular snake, we observed scars all over its tail, so it had tangled with some predators in its long life.”

Anyone who comes across a rubber boa or any other rare snake in SLO County may contact Emily Taylor at etaylor@calpoly.edu.

 

A full view of the rubber boa found in August at Montaña de Oro State Park.