The river otter that took up residence in the Sutro Baths ruins at Ocean Beach appears to have moved on; he has not been seen for weeks.
Dubbed Sutro Sam, he was the first river otter spotted in San Francisco in decades. The young male attracted so much attention from sightseers that Golden Gate National Recreation Area officials had to set up signs to remind people to keep away from the wild creature.
But Sutro Sam has not been spotted in the murky waters north of the Cliff House since Feb. 23, said Megan Isadore, co-founder of the River Otter Ecology Project. She said there are several possibilities for why he moved on, including that it’s the beginning of mating season and Sutro Sam might have gone searching for a female.
Also, a River Otter Ecology Project volunteer who was checking on the otter daily noted that in the last few weeks Sam was in the ruins, the size of the fish he was eating were noticeably smaller. Sam was spotted eating large carp and goldfish when he first arrived in September, but he may have exhausted the supply in the large pool, Isadore said.
Where Sam went is as much a mystery as where he came from.
It’s assumed he came south from Marin County since there is not much of a river otter population south of The City until way down by Los Gatos, Isadore said. She said he likely arrived by sea and left the same way since the overland route through The City would be treacherous for a river otter.
Part of the River Otter Ecology Project is DNA testing of the Bay Area river population.
The group is hoping that droppings and hair passively collected from Sutro Sam may yield genetic material that could help show how he is related to other area river otters.
“I am delighted that so many people got to see a wild river otter in San Francisco,” Isadore said.