One Tam Launches New Inventory of California Giant Salamanders

By Science Communication Specialist Michela Gentile and Senior Program Manager Dr. Lisette Arellano, Golden Gate National Parks Conservancy

Do you see it beneath the brown fern frond? California giant salamanders have been spotted in and around various streams in the Mt. Tamalpais region, but while we have some knowledge of their distribution, we need more information to conserve them.

Golden Gate National Parks Conservancy / Sara Leon Guerrero

July 2023 - Have you ever seen the elusive California giant salamander (Dicamptodon ensatus)? This California endemic amphibian is one of the largest terrestrial salamanders anywhere, reaching 6-12 inches. Beyond their size, they are also identified by their blotchy brown coloring, with white to yellow underside. Although not federally listed, the California giant salamander is considered a special status species in need of conservation. They live year-round in headwater streams and adjacent riparian areas and are excellent indicators for the health of these habitats.

This species was identified as a knowledge gap in One Tam’s 2016 effort to understand the health of the whole mountain, known as Peak Health. We know that the Mt. Tamalpais region supports California giant salamander populations in various streams, but while we have some knowledge of their distribution, we need more information to conserve them. To help fill the gap, this summer we embarked on a new effort using crowd-sourced observations from iNaturalist. The project is being led by Dr. Lisette Arellano, senior program manager at the Parks Conservancy and head of our One Tam Community Science Team. Assisting this exciting investigation are our two summer interns, Angel Meza (biology student at City College of San Francisco) and Bria Boose (biology master’s student at San Francisco State University).

The San Francisco Bay Area Network coho and steelhead monitoring team captured and recorded this California giant salamander during their spring 2023 smolt trapping season.

Point Reyes National Seashore Association / NPS / Tara Blake

The data will be used to make a map of salamander occurrence, to estimate approximate salamander age, to document behaviors, and to detect instances of sick or dead salamanders. This information will be summarized and shared with One Tam partner agencies to assess the health of California Giant Salamander populations on Mt. Tamalpais and inform possible conservation actions.

Anyone can contribute to this project through iNaturalist – learn how at onetam.org/salamander.

For more information

• Visit One Tam's California Giant Salamander Inventory webpage
• Contact Senior Program Manager Dr. Lisette Arellano, Golden Gate National Parks Conservancy

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