More great coverage of the otter recovery out of Sonoma. Humans are happily taking credit for restoring the streams and improving their fish, but I’m guessing they had some other flat-tailed helpers along the way. Great photo from beaver friend Tom Reynolds too.

River otters coming back to Sonoma County

Winter rains have swollen streams and rivers, recharging groundwater, filling ponds and lakes, and making more visible the network of waterways that traverse Sonoma County. One species that makes good use of this aquatic web is the river otter. Have you seen a river otter recently? If so, you’re one of a growing number because river otters are on the comeback.

The Bay Area is seeing a rebound in river otter populations. Experts speculate that this is a testimony to many overlapping efforts to improve water quality and restore habitat. Megan Isadore of the River Otter Ecology Project says, “The most amazing thing about the otters’ return is they have done it completely on their own. There have been no efforts to reintroduce otters. What we are seeing is the response of the species to improved conditions.”

This time of year, female otters are denning and having pups. Maternal dens can be under large fallen trees or even inside old beaver dams. Each female gives birth to between one and four pups and then, shortly after, will breed with a male in preparation for the following winter. One amazing fact is that females experience “delayed implantation,” harboring fertilized eggs and then keeping the pregnancy dormant for up to 10 months.

Most young otters live with their moms for at least a year, with females often staying to act as helpers with the new pups. Young adult males leave after a year and strike out on their own to find and establish their own territory. Otter observations are often made during the February through March time frame as these disbursing juveniles take chances crossing subdivisions, ridges, roads and farm fields in search of a new and abundant source of fish.

Otters have benefited from on-the-ground habitat improvements and from the evolution of environmental policy. In 1961, California outlawed commercial otter trapping. Otters were trapped for two reasons: to sell their rich, thick pelts to the garment industry and sometimes to protect localized fish populations. Otters have large home ranges and are constantly on the move, so large scale fish populations remain intact even if individual fishing holes get temporarily depleted.

Another policy assist came from the 1972 passage of the Clean Water Act. This ushered in a generation of investments in cleaning the bay and eliminating many sources of industrial and agricultural pollution. Like bald eagles and peregrine falcons, otters illustrate that policy decisions do matter, and that we can repair degraded environments. As recently as 1995, state maps did not even show Marin and Sonoma counties as part of the river otter’s range. Today, scientists confirm that otters occupy much of their former Bay Area territory.

We’ve all benefited from the evolution of environmental policy, that’s for sure. But I’m also thinking that the recovery of another mammal who actually happens to make the water cleaner and increase the fish population might have helped a little too. (Ahem). Congratulations to Meghan Isadore and her merry band of Otter Spotters at the River Otter Ecology Project. We’re always happy when creeks draw human eyes!

Here’s a lovely promotional message from an otter himself demonstrating who he believes has helped his survival. Just look at the shapes he is posing under for a clue about who he thinks helped him most. This video by Moses Silva on Valentine’s day a few years ago shows an otter grooming atop the old beaver lodge.

Although, if otter trapping has really been outlawed 55 years in this state I’d be cautious about how much promotion of their “healthy recovery” I’d want to do in the media. Just sayin’. The nearly extinguished beaver population was protected for all of around 11 years and they decided the population had rebounded enough to restore trapping. River otters have been spared in California for more than half a century!

Ixnay on the opulation-pay evovery-ray is my advice.