In this, the driest part of the year in Sonoma County, you might take a minute to consider creatures that are increasingly appreciated as watershed heroes — the beavers.

Beavers (Castor canadensis) are aquatic mammals that live in streams and lakes and are well known for building dams and lodges, but they have long been misunderstood, ignored or maligned.

Today, however, scientists and land managers recognize them as a “keystone” species, protecting habitat for many other plants and animals, and providing water security for people.

Have you ever seen a beaver? Don’t mistake them for otters. Beavers are actually members of the rodent family.

 They don’t eat fish, and they have big, flat tails. They are herbivores and nibble on all sorts of stream-side vegetation, including willows, cottonwoods and grasses. They are usually shy, and because predators like coyotes and mountain lions hunt them, they construct wood and mud lodges or bank burrows that they access through underwater entrances.

Beavers live in family groups or colonies led by the breeding male and female, and are joined by the juveniles from previous litters who help watch over the kits of the year. At 3, juveniles leave home in search of new territory, sometimes as far away as 30 miles.

Beavers once numbered in the millions all across North America. Because they were prized for their fur, they were largely killed off in the 1700s and 1800s. In California, they were exploited first by the maritime Russian-American fur traders who navigated up and down the coast, and later by fur trapping Mountain Men who came overland from the East.