"We've lost cats to coyotes and cars over the years," John Demma said matter-of-factly, acknowledging that he lives along "a natural corridor" where Beach Gulch Creek meanders through acres of watershed area next to Woodside Road.
"We get mountain lions, foxes and bobcats, too," he said, but what's unnerving is seeing "two or three coyotes on the creek within 100 feet of the house."
Just down the road, his neighbor, Gina Baldwin, had a cat show up one morning "with his leg dangling." She never heard a noise, but suspects coyotes might have mauled him. She said she has seen them "at my fence taunting the dogs" when her dog was in heat.
Coyotes have been known to breed with dogs and wolves, but as they reach the end of mating season this month, coyotes are mostly seeking out other coyotes in the area.
They are on the prowl, calling to each other more than usual. Coyotes usually hunt between dusk and dawn, but can be spotted moving around during the day.
Biking through Portola Valley, Dave Boyce has seen individual coyotes on Portola Road dart by him in daylight. It's when he hears a pack of them howling at night that spooks him and gets him thinking, "I wonder if they go after people?"
In rare instances, there have been attacks on humans, but "coyotes by nature are very fearful," according to Nikii Finch-Morales, director of wildlife at CuriOdyssey, formerly called Coyote Point Museum in San Mateo.
The museum has a coyote on exhibit, a female named Sierra who was confiscated by the California Department of Fish and Game when she was just a pup. Ms. Finch-Morales said the coyote was tied up in someone's backyard being kept as an illegal pet. Sierra is "very unsocialized," afraid of dogs, and unfit to be released into the wild.
Coyotes "are wild animals, and the more wild spaces we take up, the more we have to share the environment with them, " she said.
She believes the best way to co-exist safely with coyotes is to avoid attracting them into the neighborhood. She suggested "not leaving out food or water" and securely closing garbage cans because "coyotes will dumpster dive as much as raccoon or skunks."
Coyotes "prefer meat (rodents and rabbits), but they're omnivores and will eat fruit and nuts to fill them up. They're opportunists and they're not that picky," she said.
They will eat other mammals and don't care if it's a fresh kill or road kill.
"If you have small animals such as a cat or a small dog, a Chihuahua or Yorkie, don't leave them outside unsupervised," she advised.
Ms. Finch-Morales said keeping property "uncluttered, closed and clear" is also important because coyotes are known to make dens in open storage and gardening sheds, and/or in heavily planted and protected areas.
Visit keepmewild.org for tips from the California Department of Fish and Game on how to make yards less welcoming: put away bird feeders at night, cover compost piles, pick up ripe fruit off the ground, and install motion-sensitive lighting.
"If followed by a coyote, make loud noises," the website advises. "If this fails, throw rocks in the animal's direction."
Coyotes are territorial but can cover a couple of miles while hunting, and run at up to 40 mph. Adult coyotes have brownish gray fur, large ears, and bushy tails. They can weigh between 20 to 45 pounds and have a keen sense of hearing, smell and sight. They also dig and jump well.
The Wildlife Center of Silicon Valley recommends fencing should be 6 feet tall and 6 inches below the ground to keep coyotes out. To safeguard poultry and rabbits, the best option is a fully enclosed structure.