Marin Headlands’ Coyotes Tracked

Don’t be surprised if you catch sight of a coyote wearing a collar when you’re hiking in the Marin Headlands. Scientists from the Golden Gate National Recreation Area (GGNRA) recently trapped, ear-tagged, collared and released seven coyotes in the Marin Headlands for a research project.

The GGNRA brought in a wildlife trapper from Utah to humanely trap the Marin Headlands coyotes during September and the first part of October. No other wildlife or dogs were captured accidentally, though a few people disturbed the traps.

The scientists collected blood and other samples from the coyotes to amass data on diet, genetics and disease exposure. Additional information will be gleaned from the high-tech collar, which contains a GPS receiver. Every two hours, it notes the coyote’s location by beaming the data to a satellite and then back to a computer, allowing researchers to monitor the coyote’s movement patterns.

They’ll also assess coyote behavior in the wild regions of the Marin Headlands versus developed areas, such as parking lots and vista points where people gather. A major goal of the project involves discouraging people from feeding coyotes and reducing the number of human-coyote encounters. Educating the public is essential.

“The coyotes in the Marin Headlands are habituated to people and dogs,” said Bill Merkle, the wildlife ecologist heading up the Marin Headlands study. “They have a neutral response. That’s OK. It’s when coyotes are used to being fed, when they start approaching people and almost beg, that’s when bad things happen.”

Often misunderstood, coyotes are native to North America and were in Marin long before humans. In fact, the town of Olema is named after the Miwok word for coyote. Though no one knows how many coyotes live in the county, the California Department of Fish and Wildlife estimates up to 750,000 live across the state. They’re here to stay.

“We want people to appreciate coyotes,” said Jonathan Young, wildlife ecologist at the Presidio Trust in San Francisco. “People fear what they don’t know, and there is a lot of misinformation. Coyote rabies is not even on the radar in California. A coyote weighs an average of 30 pounds and eats rodents.”

In their role as top-level predators, coyotes control the populations of rodents and mid-level mesocarnivores, such as raccoons and skunks. They’re an essential part of the food chain.

“Coyotes perform an important ecological function,” said Camilla Fox, founder and executive director of Project Coyote, a national nonprofit based in Larkspur. “One coyote can control 1,800 rodents in a year.”

That is a reason Governor Newsom just signed the first law in the nation banning second-generation anticoagulant rodenticides, which are commonly used and known to kill wildlife. These poisons are consumed by rodents, which are then preyed upon by other animals, enabling the toxins to move up the food chain to apex predators, such as coyotes, mountain lions and raptors.

The Presidio prohibited the use of rodenticides long ago, as they have resident coyotes and other predators in the urban park. The Marin Headlands ecologists are working with the Presidio, which has monitored coyotes since 2016. Many of the 16 animals tracked in the Presidio over the past several years left the park during the fall dispersal season and were killed by cars, said Young. Pups born in the spring often disperse from October through December to establish a new territory and find a mate. More coyotes are hit by cars during this period than any other time of year.

Unfortunately, vehicles recently killed two coyotes in the Marin Headlands project, in separate incidents, on Highway 101 near Sausalito. That leaves five animals, all healthy, in the study.

Two of the remaining coyotes live in busy areas. A female coyote, estimated to be 10 years old, was trapped near the Rodeo Beach parking lot. A male, aged six to seven, was caught at Vista Point, overlooking the Golden Gate Bridge. They likely remain in places frequented by humans because people provide them with food. There is a saying about feeding these wild animals: a fed coyote is a dead coyote.

“Coyotes are really smart, really adaptable,” said Bill Merkle, the wildlife ecologist who is heading up the Marin Headlands study. “As soon as they start being fed, they learn it’s an easy way to get a meal. They’ll come around to the car window looking for handouts.”

With this unnatural conditioning, coyotes lose their fear of people and may exhibit bold behavior to obtain food. Since it’s illegal in California to relocate a coyote, it will be euthanized if it becomes too aggressive. The GGNRA euthanized three coyotes, two last year and one this year, from the Tennessee Valley Trail area in Mill Valley. In all three cases, the coyotes were aggressive with people.

Last month, a coyote bit a woman on the leg at Tennessee Valley Beach. The woman was treated at the hospital for minor injuries. Park officials took a piece of her clothing to identify the animal from DNA. If a coyote is trapped in that territory, they will know whether they caught the offending animal.

“Coyote bites are a rare occurrence,” Merkle said. “Tennessee Valley is a complete anomaly. It’s a bite hotspot.”

Merkle believes Tennessee Valley visitors feed coyotes. It’s a people problem, he said. After an aggressive coyote is removed, a new coyote often comes in to take over the territory. The cycle begins again when that animal learns to associate humans with food.  

The presence of dogs may also set up conflicts with coyotes. Off-leash dogs sometimes harass or chase coyotes and disturb dens when the animals are birthing and raising their young, Fox said. This behavior could result in a coyote attack on a dog.

The Presidio closes trails to dogs when a coyote den is in the area, because 99.9 percent of the problems occur during pupping season, Young said. In the Marin Headlands, off-leash dogs are allowed in some areas; however, it is recommended to keep dogs on leash during the pupping season from April through August.

Coyotes are typically wary of people, but if one does approach, do not run. Haze it forcefully by yelling, maintaining eye contact, waving your arms and stomping your feet. Throw small objects near the coyote to scare it. In almost every instance, it will leave. Calmly walk away once the coyote retreats.

“I think we are lucky to live in such a beautiful area where we share this landscape with a variety of wild animals,” Fox said. “We can cherish that gift and recognize there are ways to coexist with our wild neighbors.”If you see a tagged coyote in the Marin Headlands, try to photograph it from at least 50 feet away and report your observation on iNaturalist, the social network for naturalists. For more information on coyotes, visit

Nikki Silverstein
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