Stanford
Conservation Program
Lagunita in the fall with a dry basin and green and orange shubs and grass.

Environmental Stewardship and Conservation at Lagunita

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Stewardship of Biodiversity at Lagunita

Stewardship efforts at Lagunita often focus more broadly on the biological community. The Conservation Program has supported or implemented projects focused on weed control, native plant restoration, trash and waste management, and bird and bat box installation. In particular, recent efforts have focused on understanding nectar availability at Lagunita and increasing the narrow-leaved milkweed population at Lagunita. Narrow-leaved milkweed is the host plant of the monarch butterfly and provides a late-season nectar source for many native invertebrates.

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Conservation of Protected Species

Lagunita currently supports two protected species: the California tiger salamander and an intergrade population of common gartersnake that is related to the San Francisco gartersnake. Lagunita and these two species are covered by Stanford’s Habitat Conservation Plan (HCP). Stanford’s HCP ensures proper stewardship of Stanford lands and legal compliance with Federal and State Endangered Species Acts.

Compliance with Endangered Species Acts is achieved through “incidental take permits” which permit specified harm to protected species under the condition that that conservation actions provide more benefit to the protected entity than the negative impacts caused by the harm. The HCP prohibits access to the Lagunita basin. However, the basin is still usable by Stanford affiliates for research and other activities, as long as they obtain a foothills use permit here.

The process of creating the HCP began in the 1990s. The HCP was approved by the U.S Fish and Wildlife Service in 2013 and minor changes for the California Department of Fish and Wildlife were approved in 2016. The HCP is effective for 50 years.

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Habitat Enhancements for Protected Species

Wildlife Migration Tunnels

One of the early conservation challenges for California tiger salamanders was road mortality. On a single rainy night, hundreds of migrating salamanders could be killed along Junipero Serra Blvd. In the early 2000’s three tunnels were constructed to allow California tiger salamanders to migrate safely from Lagunita to open space at the Stanford Dish. In 2017, in collaboration with USGS, we installed drift fences adjacent to the tunnels to further reduce road mortality. An innovative system of camera traps allows the Conservation Program and collaborating researchers to study California tiger salamander movement through the tunnels and along the drift fences.

Pond Creation

Eight ponds suitable for salamander reproduction were constructed upslope of Lagunita, across Junipero Serra Boulevard, in the Stanford Dish foothills. These ponds expand the reproductive opportunities for California tiger salamander to an area safer for the salamanders than Stanford’s suburban campus. The ponds became operational in 2006, and in 2024 California tiger salamander reproductive effort was documented in six of the eight ponds.

Cover Piles

California tiger salamanders spend most of their lives underground in burrows created by small mammals, particularly those created by California ground squirrels. Therefore, the Stanford Conservation Program takes measures to enhance habitat for small mammals. Cover piles created from logs or rocks are features where small mammals can seek refuge from predators. They often encourage digging by California ground squirrels and other small mammals. Cover piles can be observed at Lagunita as well as at conservation easements across Stanford’s foothills.

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Monitoring Approaches: How are our salamanders doing?

The Stanford Conservation Program monitors egg, larval, juvenile, and adult life stages of California tiger salamanders. We most commonly use adult capture-recapture data to track population trends over time.  Each adult California tiger salamander has a unique spot pattern. When we capture a salamander, we take a photo of the salamander’s back and compare it to past photos in our database to determine if we’ve captured this salamander before or not. Based upon the number of individuals captured and recaptured, we can extrapolate a rough estimate of population size.

Here are our rough estimates of Stanford’s adult population size over the last several years:

Estimated Population Size of Adult California Tiger Salamanders graph
Graph showing estimated number of adult California tiger salamanders over the past four winter seasons. Population estimates vary from year to year, centering around 1500 individuals.

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Why are California tiger salamanders so important? What do they do for their ecosystem?

A perspective from Stanford Conservation Program Manager, Esther Cole Adelsheim, PhD:

“In terms of why should we care about California tiger salamanders, I think there are lots of reasons. First this species is endemic to California – it is only found here. The species is also at risk of extinction, largely due to habitat loss through land use type conversion to agriculture and urban/suburban development. I believe it to be an ethical responsibility of ours to care for species other than ourselves.

“California tiger salamanders are fascinating and beautiful creatures – a species I hope that my children will be able to show their children. Also a species that I hope future generations of Stanford students will be able to study, learn from, and appreciate.

“In terms of the species interactions with the ecological community, it is often difficult to predict the full ramifications of the loss of single species. However, when abundant, California tiger salamanders are a major driver of food web interactions in vernal pools – they are gape limited predators and so as they grow, they eat anything they can fit in their mouths. When they first hatch, California tiger salamanders feed on small invertebrates like fairy shrimp, as they grow they eat larger invertebrates like clam shrimp. As the larvae develop even further they will eat Sierra chorus frog tadpoles and at high densities when food is scarce, they will eat each other! California tiger salamanders themselves are consumed by Great Blue Herons, among other generalist predators.”

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How You Can Help California Tiger Salamanders

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California Tiger Salamander Research at Stanford

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What about the intergrade gartersnake?

We estimate that the intergrade gartersnake population at Stanford has less than 30 individuals. They have been heavily impacted over the past several decades by drought, development, and declines in California red-legged frog populations. The measures taken to create and enhance habitat for California tiger salamander (wildlife tunnels, pond creation, and cover piles) are also expected to benefit the gartersnake population.

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