Nancy Zacher was prepared when a coyote swept in and snatched her miniature cockapoo. She blasted a small airhorn she carries in her pocket, the same type she once used to call her four kids home for supper. The coyote released Bo and ran off.

They were walking on Marin Way, around the corner from her house in Bolinas. She didn’t have Bo on a leash because he rarely strays far from her side. But she had the airhorn, which she credits with saving his life.

Ms. Zacher knows of two other people whose dogs were recently attacked by coyotes in Bolinas, stirring a lively discussion on the social media app NextDoor. One traumatized woman watched a coyote run off with her little black pup in its mouth, never to be seen again. The other learned a lesson from Ms. Zacher and saved her dog with a blast from an airhorn. 

“If she hadn’t had her airhorn, that dog would have been an hors d’oeuvres for the coyote,” said Ms. Zacher, who has been summering in the Bolinas all her life and retired there seven years ago. “It was a Chihuahua.”

Experts say coyote attacks on people and pets are extremely rare. When they do occur, it’s usually in neighborhoods where people have been feeding them, intentionally or unintentionally, by leaving pet food outdoors or filling unlatched garbage cans with food scraps. The best way to keep them out of your neighborhood is to avoid luring them in.

There are no hard data to measure West Marin’s coyote population, but it’s clear that their numbers are growing across California and the country. They are becoming bolder about entering residential neighborhoods, even in big cities like Los Angeles and San Francisco. Dave Press, a biologist with the Point Reyes National Seashore, said it’s safe to say West Marin’s coyote population is growing, too, and that some are becoming less fearful of people.

Accounts of coyote attacks in Marin County abound. At a packed community meeting in Belvedere earlier this month, residents lined up to share stories of coyotes setting upon their pets. 

“My dog was attacked,” one resident said. “I’m not going to wait for my child to be attacked.”

“We need to get rid of aggressive coyotes,” said another. “They need to be taken out.”

“They need to be shot,” said a third.

Ms. Zacher has reached a different conclusion. “We just have to live with them,” she said. “We don’t go out at dawn or dusk. That’s when they seem to be around. I’m just more vigilant.”

Coyotes are here to stay, said Daniel Dietrich, an Inverness wildlife photographer and filmmaker who serves as an ambassador for Project Coyote, a Marin nonprofit that encourages people to learn how to coexist with coyotes. 

“They’ve been here a very long time, long before us,” he said. “It’s not anything new. They don’t come to our neighborhoods to hunt cats and dogs. They come to our neighborhoods because they’re highly adaptable. We should respect them and be conscious of them, but we shouldn’t be afraid that they’re going to snatch our children on their way to school.”

Ms. Zacher, who recently turned 81, was anything but afraid when Bo—short for Bolinas—had his run-in last October. They were walking with her second cockapoo, Barkley, who had paused down the street to sniff a neighbor’s garbage can. When she glanced in Barkley’s direction, she heard Bo frantically yelping behind her. She turned to find him next to a menacing coyote, just 15 feet away.

Ms. Zacher said her adrenaline took over. She charged the coyote with her airhorn, blasting it until he bolted. She went to pick up Bo, but he resisted, so they set off for home on foot. “The next thing I know, two coyotes are coming at us from 10 o’clock and 2 o’clock,” Ms. Zacher said.

Aiming left, then rotating right, she blared the airhorn until they fled. It wasn’t until she got home that she realized Bo was bleeding; his blood had spattered onto the hardwood floor. He had a deep puncture wound in his shoulder, and light wounds on his jugular veins.

His eyes were wide open and he wasn’t moving, and she wondered if he was dead. “He just lay there. He was in shock,” she said. They raced to the animal hospital in Fairfax, where Bo spent the night recovering and the E.R. staff spoke in awe of her. 

“To have an 81-year-old lady taking on two wild animals!” Ms. Zacher said. “They weren’t going to get my Bo!”

Wildlife experts offer a variety of commonsense steps for avoiding mishaps with coyotes. If you’re taking your dogs out, keep them on a short leash, no longer than 6 feet. If you have cats, keep them indoors. Keep your yard free of tempting morsels, trimming the lower branches of fruit trees and collecting any fruit that falls to the ground. Make sure garbage cans are inaccessible, and don’t leave pet food or water outdoors.

Experts recommend hazing coyotes—that is, sending a firm but nonlethal message that they are unwelcome. Make noise. Throw rocks in their direction. Get big. Wave your jacket over your head. Jump up and down. And if you have an airhorn, give it an aggressive blast.

“Lots of people in Bolinas have airhorns now,” Ms. Zacher said. “I never leave the house without one.”

In general, coyotes want nothing to do with people. But they will expand their territory anywhere they feel unthreatened and resources are available. 

“Coyotes are not aggressive, but they’re opportunistic,” said Lisa Bloch of the Marin Humane Society. “They look for opportunities and we humans unfortunately keep providing easy ones.” 

The biggest mistake is to intentionally feed coyotes out of the misguided notion that you’re being kind, Ms. Bloch said. One person kept feeding a coyote on a stretch of Highway 1 near Stinson Beach and, naturally, he kept returning for more.

“He would come up to cars and say, ‘Oh, are you going to feed me, too?’” Ms. Bloch said. “If coyotes see that humans are not scary and that we might even provide them with an easy meal, they’re going to make a habit of trying to visit us.”

Project Coyote has a saying: “A fed coyote is a dead coyote.” If we lure coyotes near our homes, they are more likely to cross busy streets and get hit by a car. And they might eventually raise the ire of neighbors like those in Belvedere who demand that the authorities remove them by any means necessary.

“If you respect wildlife, don’t feed them,” Ms. Bloch said. “Let them remain wild.”