What follows is the select, concise version of the results:

• River otters, extirpated from the Bay Area for decades, are back in all counties of the Bay Area except San Mateo, according to our nearly 1200 citizen science sightings in three years!
• River otters are breeding successfully around much of the SF Bay and Marin and Sonoma coasts.
• The first-ever census of river otters in Marin County shows about 50 river otters inhabit the stretch of coast from the Golden Gate north into Tomales Bay.
•  Car strikes account for the highest mortality discovered through our research.

This matters because:

• River otters are a sentinel species. Their return and continued good health tells us that our conservation and restoration efforts around the SF Bay are working!
• Our research is the first to elucidate how river otters fit into our local ecosystems. Because river otters are a predator species, and may be a top predator in many areas, we need to understand their function in their ecosystem. This is especially important where conservation efforts are geared toward endangered species.
• Our population studies on river otters provide a basis for determining how their populations are affected by oil spills, and help us with mitigation efforts.

Next steps:

• Continue population monitoring;
• Build on our work to tease out demographic information, including population numbers, male/female sex ratios, family relationships, range and dispersal patterns. This is accomplished by genetic analysis of scat, which we have begun in partnership with San Francisco State University’s Genetics & Transcriptomics Analysis Core;

Begin diet study analysis when funding becomes available.