By Leslie Allen
Special to the Express
An iconic species of Putah Creek, and undoubtedly one of the most entertaining, North American River Otters are popular with creek visitors because of their endearing appearance and playful antics. These extremely adaptable animals can tolerate hot and cold climates, high and low elevations, and fresh and salt water. Locally, otters live in riparian zones along Putah Creek.
They are commonly seen feeding in weed beds bordering the main channel of Lake Solano, or grooming their dense coats while hauled out on logs or rocks at the creek’s edge. Low-frequency chuckling sounds and loud snorts often telegraph their presence.
River otters are well suited to aquatic environments. A long tail and webbed hind feet propel them at speeds up to seven miles per hour. Their eyes and ears are located high on their heads for surface swimming. A translucent third eyelid, or nictitating membrane, protects their eyes and allows them to see when swimming underwater. Additionally, they can close their ears and nostrils underwater. Long, highly sensitive facial whiskers aid in locating and capturing prey.
Noted for their boisterous play, otters owe their boundless energy to a very high metabolism, which requires that they eat often. Aquatic organisms including fish, frogs, crayfish, turtles, mollusks and insects make up the majority of their diet, though they also eat small mammals and birds. On this varied diet, they can grow to four feet in length and 30 pounds, though females are generally smaller than males.
Baby otters (sometimes confused with their smaller mink cousins in the Mustelidae family) are usually born in spring, and commonly stay with their mother until she dens again the following year. Provided it survives its first year of life, a typical North American river otter will live to the age of 12. However, the oldest river otter on record was 27 years old. This relatively long life span provides creek visitors an opportunity to ‘get to know’ local otters.
For instance, one particular female otter, recognizable because she’s blind in one eye, has successfully raised litters of kits on Lake Solano for the last four years in a row. Another younger female, identifiable by a missing toe on her right front paw, raised her first litter of kits there in 2022. (Note: binoculars allow for observation without pressuring wildlife.)
River otters are an indicator species. They are apex predators that eat at the top of the food web, so when pollutants enter their watershed habitat, they are among the first to show signs of distress. Therefore, a strong and active river otter population is indicative of a healthy riparian habitat. The thriving river otter population in the Putah Creek watershed suggests creek conservation efforts are working.
For more information, visit putahcreekcouncil.org
