Duane Chamberlain has been raising feed grains and cattle in California’s Sacramento Valley for more than a half-century.

But it’s only been in the last 20 years or so that he’s sought the help of nature itself.

Chamberlain, who owns a ranch and feed store in the heart of rural Yolo County and farms in numerous locations, began looking to beneficial birds to control the rodents and problem insects that can affect his crops.

Today, many of his fields have wooded edges that support over-wintering birds, and he reconfigured a slough on his property to be more attractive to California quail and pheasants.

Chamberlain says he has identified as many as 70 different birds on his ranch south of Woodland, where his Windmill Feed store sells the alfalfa, grass and oat hay he produces.

“I like the barn owls; they’re great,” Chamberlain told about 50 growers and wildlife professionals during a recent workshop at his ranch. “You have to be careful walking into a barn. They like to fly out and leave their little markings on you.”

A GROWING NUMBER

Chamberlain is among a growing number of farmers who are looking to birds as a natural means of controlling pests as state regulators cast an ever more wary eye on the use of chemical pesticides.

The concept of “economic ornithology” actually gained steam in the early 1900s as researchers looked closely at bird diets to learn which species were the most helpful, notes Jo Ann Baumgartner, executive director of the Watsonville, Calif.-based Wild Farm Alliance.

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Over 700 academic papers were published, she says. Much of the work was tabled when pesticides were brought to market in the middle of the century. But in about 2000, “people started looking at birds as pest control partners,” she says.

Some birds are more helpful than others, explains Sara Kross, a program director at Columbia University’s Department of Ecology, Evolution and Environmental Biology. Songbirds in nest boxes or vegetative habitat are particularly good at insect control, while raptors in artificial perches, nest boxes or habitat help control other birds and rodents, she says in a worksheet handed out to growers. Herons and egrets attack rodents in flood-irrigated fields, she adds.

ATTACKING WEEVILS

“In alfalfa, we found that birds decrease the number of alfalfa weevils, which is a major pest of alfalfa in this area,” Kross said during the Yolo County workshop. “The birds reduced their abundance by 33 percent.

“If you didn’t have birds, you’d have to deal with them by chemical means,” which can be “like looking for weevils in haystacks,” says Kross, who did postdoctoral research at the University of California-Davis and also taught at California State University-Sacramento.

Another helpful bird is the barn owl, she says. In studies, about 95 percent of the insects in barn owls’ stomachs were agricultural pests, she says.

“Barn owls are not super-picky about where they want to nest,” Kross says. “They like to nest in boxes made of wood.”

A recent survey found that 30 percent of boxes provided for the birds in Napa County were occupied, while as many as 70 percent in the Sacramento Valley were occupied, she says.

“Barn owls are an optimum predator of pest rodents because they don’t hate each other,” while other raptors are more territorial, Kross says.

PROBLEM BIRDS

But other birds need to be “coexisted with,” she and other experts say. Those include some crows, sparrows, starlings, blackbirds and other omnivores and granivores, the Wild Farm Alliance advises.

Some birds are beneficial at certain times of year but must be kept away from the crop. For instance, the red-winged blackbird is useful in the spring when they feed insects to nestlings, but they can also consume a crop later in the year, the WFA explains.

Just seeing birds in a field isn’t always a sign that they are causing damage, Kross cautions. Growers should know what bird damage looks like and closely examine representative samples of the crop in multiple locations within each block, she says.

Bird deterrents come in many forms, ranging from scarecrows and alarm calls to use of a trained falconer to scare away problem birds. Growers commonly protect their crops with bird netting, which can be expensive. Farms that have suffered crop losses because of bird damage can do a cost-benefit analysis to determine if netting is worth the expense, Kross advises.

PLANTING HEDGEROWS

As for attracting beneficial birds, some growers are planting hedgerows on their fields’ edges, which can also benefit pollinators by adding feed while preventing excess runoff from getting into waterways.

Hedgerows consist of vegetation, including trees, shrubs, forbs and grasses, that is planted in linear or other configurations. They can include “trap crops” which attract pests or a mix of species that flower at different times of year to maintain a year-round source of food and habitat for beneficial insects, explains a pamphlet from the Community Alliance with Family Farmers and the Santa Cruz County Resource Conservation District.

“There’s more and more interest in hedgerows on farms to bring back some of this diversity,” says Rachael Long, a UC Cooperative Extension farm advisor based in Woodland.

In recent research, growers with hedgerows did not have to spray insecticides as much as those without the plantings, Long says. Setting up hedgerows pays for itself financially in about 12 years, or seven years if you consider the benefit from providing more feed to strengthen pollinators, she says.

“What we’ve found with birds is hedgerows can’t be isolated,” Long says. “They need to be connected to other riparian areas.”

INSPIRED BY FFA

Inspired as an FFA student in Orange County, Chamberlain had served in the U.S. Army and studied animal science at UC-Davis when he and a friend started farming in Yolo County in 1963. Today, Chamberlain Farms operates on about 60 sites, including the Yolo property and a ranch in Glenn County. Chamberlain is also a fourth-term Yolo County supervisor.

A university scientist first got him interested in birds in the 1960s, and he’s been using them as part of field management for about 20 years, he says.

With help from Audubon California and a local conservation district, Chamberlain turned a steep, narrow, fast-moving slough on his property into a wider, shallower waterway with native plants, which provides flood control as well as habitat.

With egrets and herons around, the start of irrigation season means a purge of troublesome rodents and bugs.

“When you go out there, you can tell where the water is,” he says. “When the water’s in the field, the crickets and moles come up for air, and here comes this little lunch wagon. The birds just eat their way down the field.”