By Anne Bremer
Although the winter rains tend to send many animals (and humans) scurrying for shelter, they are an invitation for one water-loving local resident to come out and play: the California newt.
These newts spend the summer hibernating upland in damp hiding places, curled up underneath rocks, logs, or leaves. The rains are a signal for these small salamanders to emerge from their shelters and make their way to ponds, lakes, reservoirs, or slow-moving pools in creeks or streams to breed. Once they reach their ancestral breeding grounds, they undergo a physical transformation to help them navigate their new aquatic environment – their skin smooths and tails flatten for swimming. Their eggs are laid underwater, and newborn tadpoles will stay in the body of water for several months before turning into terrestrial adults and migrating upland, to begin the seasonal cycle once more.
The California newt, 5 to 8 inches long, is brown in color to camouflage with the leaves and brush that make up its habitat. When threatened, however, it will stick its tail straight out and arch backward, exposing a bright orange-yellow underbelly as a warning to predators: “Poison! Eat at your own risk!” Glands in the newt’s skin secrete a powerful neurotoxin, tetrodotoxin, hundreds of times more potent than cyanide. When ingested or absorbed through a cut in the skin, this toxin can cause death by respiratory and cardiac failure. As a result, the newts have few natural predators, apart from common garter snakes, which have developed a high tolerance for their toxicity. The newts themselves dine on small invertebrates, such as worms, snails, slugs and insects.
California newts are, as their name suggests, endemic to California. Although they are not officially listed as a threatened species, their population has declined over the years, primarily due to loss of habitat. Fortunately, members of our community have taken action to protect these newts during their annual migration. For years, dedicated volunteers in El Sobrante escorted newts across Hillside Drive to San Pablo Creek. For over 20 years, South Park Drive in Tilden Regional Park has been closed to auto traffic each year between October 31st and March 31st as newts cross it to reach Wildcat Creek. Bicyclists, pedestrians, and dog-walkers are welcome, but asked to proceed slowly and watch their step. If you find yourself in the path of migrating newts this winter, help keep them safe and enjoy them from a distance.