Wine Country’s cow herds help preserve native grasslands

To modern public land managers and conservationists, cows are working partners, enlisted in the fight to protect remaining patches of California’s native grassland ecosystems.|

On a recent bright spring morning, on a green hillside high above the blue Pacific in Jenner Headlands Preserve, a traffic jam has formed. A line of nervous black-and-white cows and calves are frozen in place halfway across a red dirt trail, while a handful of hikers, camera phones in hand, wait for them to pass.

The standoff ends when the calves finally romp off. Their watchful 1,200-pound guardians leisurely follow, munching their way across shin-high grass and yellow wildflowers, and the hikers continue up the steep slope.

The cows — Belted Galloways, which look like plump Oreo cookies with black on either end and a thick vertical white stripe around their middle — are not out wandering the rolling high slopes of Jenner Headlands by accident.

To modern public land managers and conservationists, they’re working partners, enlisted in the fight to keep the last remaining patches of California’s native grassland ecosystems from disappearing.

As Bob Neale, stewardship director at Sonoma Land Trust, explains, the cows are needed because the native grasslands that once grew in abundance across the state are now almost entirely gone. Most of the familiar golden grasslands we see today are not part of the native California environment. They’re invasive transplants.

“The once-vast expanses of native perennial grasses have been overtaken by annual species introduced by European ranchers in the last 200 years, which have outcompeted and replaced them,” Neale says.

So how do the cows help? Don’t they eat grass? It turns out that’s actually a good thing. To understand why, it’s necessary to go back and see what grasslands are all about.

California prairies

Long before humans arrived, archaeologists have found, California was home to extensive prairies and grasslands grazed by vast herds of migrating mammoths, camel-like herbivores, elk and many other species. Those native grasslands not only contained dozens of types of wild grasses, like wild blue rye, onion grass, meadow barley, fescue and bunchgrass, but they were also habitat for more than 40% of the state’s native plant species, a rich mixture including sedges and ferns and flowering species like fiddleneck, lupine and yarrow, strawberries and poppies.

Until very recently, the grasslands also supported a wide range of birds, insects, mammals, reptiles and other animals that depended on the ecosystem for food and shelter.

But in the last 200 years, the state’s native grasslands have declined to barely 1% of their original expanse, the result of development, agriculture and invasive species, according to the nonprofit California Native Grass Association. The group is working to preserve and restore California's native grasslands, which it says are among the most endangered ecosystems in the United States.

The nonprofit notes that native grassland pollinators like butterflies and bees are among the species now experiencing steep declines statewide.

The good news is that, in places like Jenner Headlands and Sears Point, in Sonoma County Regional Parks and state parks, efforts are underway to protect what’s left of the native grasslands and try to promote their return.

That’s where the cows come in.

“To stay healthy, wild grasslands require disturbance. They must have it,” says Jean-Philippe “JP” Marie, president of the native grass association and manager of UC Davis Putah Creek Riparian Reserve.

Grasslands evolved with constant and continuous grazing. Without it, over time they accumulate dense dead layers called thatch, which eventually grows so thick it smothers new growth. Without disturbance, the grasslands eventually disappear, overtaken by weedy species, woody shrubs and eventually forest.

“Something has to disturb them. If not grazing, then fire or mowing,” JP Marie says.

“Seventeen years ago, we took 400 acres near Davis back from farming, to restore it with native grassland habitat. But we still had invasive plants and nonnatives. As an alternative to herbicides, we began to experiment with cows.

“I’ve tried many different methods, but cows are now my favorite,” he adds. The cows not only reduce thatch and spread manure, they prefer to eat the more nutritious nonnative weeds and grasses first.

“With careful, planned management, they serve as surrogates for the wild grazers that once roamed California, keeping native grasslands vibrant and healthy.”

The beneficial impacts go far beyond healthy prairie. Native grasses have a vastly different effect on water, soil, fire and other natural systems compared to introduced European annuals.

“Native perennial grasses are not at all like the (nonnative) introduced varieties we see everywhere now,” JP Marie says. “(The only goal of nonnative annuals) is to grow fast, grow tall and make seed. One year, and they’re finished. Perennials, on the other hand, grow back every year. They grow back after being grazed. And they have really deep roots, as deep as 10 to 15 feet underground, where they can find water. ... Plus, their roots are constantly growing, opening tiny channels in the soil, so that when rains do come, the water percolates deep into the soil, rather than simply running off.”

Other grazing benefits

At Sonoma Land Trust, cow grazing not only helps conserve wildlands, Neale says.

“(Cows) also play an important role in conserving biomass and reducing burnable fuels.

“Grazing can affect how fire moves across a landscape. Ungrazed grasslands can form up to 2-foot-thick mats of highly flammable thatch, which can ignite into highly destructive wildfires. Managed grazing reduces thatch from 2 feet to 2 inches.”

Frazier Haney is Executive Director of the Wildlands Conservancy, the operating partner for Jenner Headlands. He says their grazing program was carefully considered when the preserve was acquired.

“Only a small portion of the property is grazed, where there is a clear ecological goal in mind,” Haney says. “Our goal is to reduce the amount of nonnative invasive grass species which, if left unchecked, suffocates native wildflowers and makes foraging difficult for raptors like Ferruginous hawks or mammals like badgers.”

And what about those photogenic Belted Galloways?

“They are a great choice for Jenner Headlands Preserve,” Haney says, “because they are smaller in stature, sure-footed and friendly.”

Using cows and livestock for public land management isn’t without its detractors. Several years ago, some environmental groups and stewards in the Bay Area publicly questioned whether running cows on park grasslands and wildflower preserves does more harm than good.

Those questions are fair, local rangeland experts say.

“People have concerns because so much of California has suffered from overgrazing, which severely degraded streams and grasslands,” says Hattie Brown, natural resources director with Sonoma County Regional Parks.

Regional Parks uses managed livestock grazing in 10 parks, and cows graze in five of those: Taylor Mountain, Tolay, North Sonoma Mountain, Crane Creek and the new Mark West Creek Park and Preserve.

The important difference, Brown, JP Marie, Neale and Haney all emphasize, is careful planning and controlled rangeland management. They’re not turning hundreds of head of cattle out to graze a fenced pasture down to dirt.

“Cows can do damage if not properly managed,” Neale says. “But good livestock management can be beneficial land management, another important tool.”

Grazing management

So, how does one manage groups of cows in parks?

“It takes a lot of focused time, thoughtful planning and active management,” Brown says. Regional Parks has a full-time, dedicated rangeland manager to assist her with the program, she says.

“A lot of what we do is very specific to each individual park, what’s growing there and the particular goal of the grazing program,” Brown says. Best practices include limiting the number of cows at any one location, fencing to restrict their grazing, using short grazing times and rotation.

“We’re always working to maintain native grassland and keep down invading shrubs and invasive species,” Brown says. “For example, timed grazing can effectively break up the life cycle of introduced annual grasses so they can’t outcompete the natives,” she says.

“But it’s not simple,” she admits. “It’s a combination of science and art and has to take into account things like the weather that year and other changing conditions.”

Haney says the Wildlife Conservancy also uses expert-informed management plans. They work to exclude wetland areas from grazing as well as other sensitive lands and graze seasonally with a certain intensity, then rotate cattle to a different pasture or off the preserve altogether.

“The number of cattle is not a static number but depends on current conditions, our ongoing research and annual monitoring,” he says.

“And cows don’t like to eat where they poop,” JP Marie notes, which means they tend to keep moving, given the chance, reducing their impact.

Should you happen to encounter one of Sonoma County’s other popular “vines” — our bovines — working in a park or preserve, offer a little respect for their role in restoring native grasslands. And watch where you step.

Stephen Nett is a Bodega Bay-based Certified California Naturalist, writer and speaker. Contact him at

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