|
Getting your Trinity Audio player ready...
|
Peninsula Humane Society (PHS) & SPCA does many things for many animals – adoptions, low-cost spay and neuter surgeries, wildlife rehabilitation and more. One very specialized program is based in the wooded hills of Saratoga, with the goal of giving California species under threat a better chance for survival.
PHS’ Imperiled Species Program currently supports two species – the Santa Cruz long-toed salamander and the giant garter snake – with plans to include a third, the Bay checkerspot butterfly. Ultimately, the hope is to support several more species.
The nonprofit’s program offers headstarting and captive breeding for these endemic species, with the aim of boosting not only their numbers, but also their health.
“Our whole goal is to rear those animals and then release them into the wild,” with the hope of supporting self-sustaining populations, said Regina Spranger, the program’s principal biologist.
Peninsula Humane Society & SPCA Imperiled Species Program principal biologist Regina Spranger stands for a portrait with shelves of garter snake tanks at the Larry Ellison Conservation Center for Wildlife Care in Saratoga on Oct. 14, 2026. Photo by Seeger Gray. 
Imperiled species lab assistant Colleen Hayward holds a young giant garter snake at the Larry Ellison Conservation Center for Wildlife Care in Saratoga on Oct. 14, 2026. Photo by Seeger Gray. 
Imperiled species lab assistant Reina Marze cleans garter snake tanks at the Larry Ellison Conservation Center for Wildlife Care in Saratoga on Oct. 14, 2026. Photo by Seeger Gray. 
Tattoos of animals on imperiled species lab assistant Reina Marze’s arm at the Larry Ellison Conservation Center for Wildlife Care in Saratoga on Oct. 14, 2026. Marze said the species are found on the East Coast, where she grew up. Photo by Seeger Gray.
The strategy for each species “really depends on what problem we’re trying to solve,” she said. In the salamanders’ case, the goal is increased genetic diversity and health as well as starting or restarting populations in certain areas. For the snakes and butterflies, a key goal is making sure more of them make it to breeding age.
These reptiles, amphibians and insects may not command as much attention as bigger, more immediately charismatic species. They’re creatures that traditionally have “a hard time getting funding and public support,” Spranger said.
Lesser-known though they may be, “they’re very interesting critters,” she said. The salamanders, for example, “live very complex lives, I think more than most people realize. Their life cycles, the way they find their mates and breed is very intriguing to me.”
The Santa Cruz long-toed salamander is a federally recognized endangered species that lives in a few isolated coastal areas in southern Santa Cruz and northern Monterey County, with much of its habitat lost due to urban and agricultural development.
Peninsula Humane Society administers a captive breeding program for the rare amphibian, collecting adults during the rainy season and bringing them to breed. After breeding, the adults are released immediately and the eggs are reared on-site. The amphibians hatch into larvae, then just before their metamorphosis they are placed at strategically chosen seasonal ponds in the wild.
It’s a long-term project that started at UC Santa Cruz, which is still a partner of the program. Thousands of larvae have been released across eight pond sites, including several hundred so far from the Saratoga-based breeding program, Spranger said. Tracking their success is a bit of a waiting game, as the amphibians only return to the ponds during the rainy season, and only once they’ve reached sexual maturity, which can take several years.
“The salamanders get put back as larvae, and we don’t get to see if they succeed for three years. It takes them years to return to those ponds to breed,” Spranger said. “Every spring, we go back and survey the ponds to track and see if the animals we put back were able to survive and come back and breed themselves.”
The giant garter snake, which recently became California’s official state snake, lives in the wetlands of the Central Valley and is a threatened species. The snake population is suffering due to habitat loss and invasive species of fish and bullfrogs that prey on the young reptiles.
The Imperiled Species Program captures gravid (pregnant) snakes and brings them to the Saratoga facility, where each snake births about 20 babies on average. The mother snakes are quickly returned to the wild, and the facility serves as a nursery as the little snakes grow.
“We raise their babies until they hit a certain size that increases their survival size,” Spranger said. Around 250 juvenile giant garter snakes were living at the facility at the time of this interview.
The federally threatened Bay checkerspot butterfly, which will likely join the program in the spring, lives exclusively in the grasslands of San Mateo and Santa Clara counties, depending on their native plants. Like the snakes, the butterflies will be part of a headstarting program, with gravid females brought in to lay eggs and then those eggs nurtured into caterpillars.
Part of the butterflies’ life cycle, Spranger explained, includes diapause – a phase when their metabolisms slow and they go dormant, spending the dry summer months underground until the rainy season kicks off and they continue their development. Habitat loss due to development and pollution, plus recent periods of drought and irregular rainy periods, have had an impact.
“In captivity, where we can moderate that, we can have a more ideal diapause so we can boost the population,” Spranger said. “Butterflies are used to what we call boom and bust periods, but right now populations are so low and so little there’s not enough to be resilient on their own.”
The Saratoga facility, which also serves as one of Peninsula Humane Society’s wildlife care centers, has rooms “waiting for their species in the future here,” Spranger said. Choosing the next candidates for the program is a big process that involves many stakeholders.
“It’s very hard to pick a species; a lot of species need help. They have to meet our program goals, and the work that we’re doing here is not just one organization: It’s a very big collaborative project,” Spranger said, one involving federal and state agencies, multiple universities and landowners, and in partnership with habitat restoration efforts.
“It’s a team effort on the decision,” she said. “We don’t want to rear all these animals and put them back in unideal situations.” While its work is collaborative, the Imperiled Species Program is privately funded by Peninsula Humane Society through a foundation, she noted.
As the principal biologist, Spranger’s day-to-day work can vary, from filling out permit forms and reports to field work, meeting with university partners and, naturally, “a lot of animal care to keep everyone happy and healthy here.” She’s joined by a few lab assistants who help with the animal husbandry, and veterinary staff working in the wildlife rehabilitation department is also there for support if needed.
Although the program’s reptiles, amphibians and, eventually, invertebrates don’t imprint on humans the way some mammals and birds might, care is still taken to ensure the youngsters don’t habituate too much to close human contact.
Adult salamanders are only kept briefly, and the larvae don’t show any imprinting tendencies, so it hasn’t been a problem.
“They’re just these little hungry, voracious water creatures. They don’t really see us,” she said of the amphibians in their aquatic states. Their surroundings are kept as close to nature as possible.
“All the tanks mimic the wild. All the salamanders are reared in very large pools, with dirt, mud, plants and rocks from the wild, where they’re from,” Spranger said. “It helps them learn and adjust in a more natural environment and helps remove any habitualization.”
The snakes are in residence for a much longer time, but they also receive minimal handling. “The baby snakes don’t really like us because the only time we pick them up is when we’re measuring them or poking them,” she said.
And for the future caterpillar residents, noticing humans is not a concern.
“The way they experience their environment does not lead to that being an issue,” Spranger said.
The most gratifying parts of her job are releasing the animals, then going back and finding successful results when tracking them.
“The first time we surveyed some of those ponds, seeing hundreds of animals, that was a very exciting moment,” she said of the salamander project. And while the giant garter snakes may not be that fond of their human caretakers, Spranger and her team care about each of them, rooting for them through every step of their journey.
“The snakes are here a long time. We track each one. It’s very nice to put them back after they’re been here for two years and you’ve seen them struggle through being a small snake and learning to hunt and grow,” she said.
Giving the little guys a good start in life is helpful, but the follow through and monitoring is an essential part of the program’s mission to track successes and failures and build long-term plans and partnerships, exploring such questions as, “What does our information mean for people doing habitat restoration? That larger-scale monitoring helps answer these larger questions, and I find that very interesting,” she said.
Not everyone can raise hundreds of baby snakes, larval salamanders and endangered caterpillars, but everyone can do something to help protect local threatened species, Spranger said, from “planting native plants and leaving natural habitats as much as possible to understanding which native animals you have around you. It helps keep you more up-to-date with what’s happening with them,” she said.
Even more important than individual action is awareness of the species and the threats they’re facing, whether that be habitat loss, invasive species, climate change or all three and more, as collective education and advocacy is needed when “trying to live as a society in a way that we can protect our local environment and our local habitats,” she said.
More information on the Peninsula Humane Society’s Imperiled Species Program is available at phs-spca.org/imperiled-species-program.
Midpeninsula Regional Open Space District is also working with national, state and local agencies to support another imperiled species of garter snake: the critically endangered San Francisco garter snake, which now lives primarily in San Mateo County, with a historic range stretching from San Francisco down to northern Santa Cruz County. A headstarting program for the rare snakes is based at the San Francisco Zoo, in tandem with longtime and ongoing efforts to preserve and improve habitats in San Mateo County. More information is available at openspace.org/stories/saving-most-beautiful-snake-world.
Subscribe to The Six Fifty’s weekly newsletter for the latest event roundups, neighborhood guides and features about Silicon Valley culture and hidden gems. Send story tips to editor@thesixfifty.com.
Redwood City’s Measure E appears to be failing, but proponents remain hopefulNovember 3, 2026 8:33 pm
