In Photos: River otters making a come back in California's Bay Area

river otter photo
© Jaymi Heimbuch

Last year and earlier in January we reported on a river otter in San Francisco that made headlines. Sutro Sam was the first otter spotted in the city in perhaps more than 50 years. But this temporary resident of the Sutro Baths ruins is just one member of the recovering river otter populations in the bay area. And he, along with his fellow otters, are a sign not only that the local efforts put into habitat restoration are paying off, but that focusing on coexisting with wildlife in general can bring back native species to an area.

Apex predators are the canary in the coal mine when it comes to the health of habitats. When the apex predators begin to disappear, we know something is out of balance. River otters, as top predators in riparian habitats, are one of the first species to go when water quality, which affects both habitat and prey, takes a dive.

So when new populations of river otters began to make a comeback north and east of San Francisco, conservationists knew that decades of trying to restore the watershed were indeed making a positive difference. From Muir Woods to Rodeo Lagoon in the Marin Headlands, from Napa to Berkeley, river otters are showing up in places they haven't been spotted in decades.

Mercury News writes, "Second only to sea otters in the plushness of their pelts, the Bay Area's river otters were hunted to local extinction by the turn of the 20th century. But river otter trapping was banned in California in 1962, and the passage of the Clean Water Act a decade later might laid out a "Welcome Back" mat for the otters by reducing toxic chemicals in the waterways. Still, river otters have taken their time to come back, or just gone unnoticed until recently."

When Sutro Sam caused a hubbub in San Francisco, Megan Isadore with the River Otter Ecology Project told newspapers, "The fact that this otter is in San Francisco and doing so well in other regions of the Bay Area, it's a good message that there's hope for the watershed."

The River Otter Ecology Project utilizes the help of citizen scientists, called Otter Spotters, who log their sightings into the project's database. This information, along with analysis of scat and other clues, is helping to fill in the story of the historic range and role of river otters in the bay area.

Isadore told the National Wildlife Federation, “The fact that river otters can live all over San Francisco Bay and the Bay Area indicates that we humans have done something right. It shows that we can make positive changes to our environment, and we surely need all the encouragement we can get in these environmentally tough times. So let’s celebrate Sam, and celebrate continuing conservation and restoration of the watersheds that support all living beings.”

Sutro Sam pauses on a rock at the Sutro Baths. He became well versed in posing for cameras during his short stint at the ruins.

One of the river otters living in Rodeo Lagoon in the Marin Headlands chomps down on a fish for breakfast.

River otters often forage for small fish and crustaceans hiding in the marsh grasses that line the shallow water of a lagoon or river.

Though brilliant swimmers, river otters are as comfortable on land as they are in the water. Even if they spend that time having diva moments with photographers.

Over land and water, they can travel as much as 26 miles in a single day when necessary, though they more often travel only a couple miles in one day.

River otters, as we know, are amazing swimmers. They can stay under water for almost four minutes, and swim at nearly 7 miles per hour. In one dive, a river otter can travel more than 400 yards!

Bonded social groups of river otters will hunt together, such as this group of three that are catching and feeding on small fish and crustaceans for breakfast. The river otters also use the same dens and resting sites, and will even leave scat in the same location.

In Photos: River otters making a come back in California's Bay Area
River otters are an indicator species, telling us when an ecosystem is in or out of balance. The reapparance of river otters in San Francisco and surrounding areas is a sign that conservation efforts are paying off.

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