In a drought, the only thing stopping the eye from seeing endless beige in parts of Yolo County are 10-foot-wide strips of mini-forests on the edges of the area’s fields.
These darker lines in the distance are the hedgerows. Indigenous bushes, shrubs and small trees like toyon, coffeeberry, coyote brush, valley oak, cottonwood, willow, mule fat, buckwheat and elderberry can be found here, and they’re used by Audubon California to study bird species diversity and populations.
Here, you can hear the northern mockingbird, yellow-rumped warbler (or butterbutt, colloquially), Lincoln’s sparrow, white-crowned sparrow, black phoebe, song sparrow, lesser goldfinch, ruby-crowned kinglet and other songs for nature’s album.
But would there be as many birds on county farmland without hedgerows?
This is the question Karen Velas, bird conservation project manager for Audubon California, is asking.
Twenty hedgerow and 20 non-hedgerow farm sites were chosen last year to study differences in bird populations, and her studies show a statistically significant difference in the number of birds found — about 35 birds at the hedgerow sites versus six at non-hedgerow sites, said Velas, whose data is not yet published.
“We take an approach where we’re trying to put in a high diversity of plants,” Velas said. “Part of the study is looking at the vegetation and trying to figure out what plants are specifically providing the most resources for the birds. What would be the ideal hedgerow?”
Velas has done numerous bird counts, in spring and winter, comparing hedgerows of varying ages and size to similar edges of farmland with barren land or ditches instead of hedgerows. Having the hedgerow on the edge of a farmed field also means farmers don’t have to take a field out of production for food, she said.
“Cooperation with landowners is the future of conservation,” she added. And even a thin hedgerow can provide spaces for nesting and food resources, Velas said.
The study is in the start of its second year in Yolo County, and hedgerow sites for study are being added in Colusa County and eventually other surrounding counties in the Sacramento Valley.
Yolo County has 17 miles of the state’s 49 total miles of hedgerows planted since 2010, said Rachael Long, farm adviser and county director of Yolo County, who has been at the forefront of hedgerow planting in the county for about a decade.
The project has been in cooperation with the Center for Land-Based Learning’s Student and Landowner Education and Watershed Stewardship program (SLEWS), Audubon California’s Working Lands program, Yolo County Resource Conservation District, National Resource Conservation Service and many landowners.
Plans to expand the hedgerow project are in the works, said Long, who just received a $125,000 grant along with the UC Davis Cooperative Extension that will involve planting more hedgerows and holding 12 workshops to educate the community about them. The first workshop will be Wednesday at the Colusa Farm Show, Long said.
— Reach Jason McAlister at [email protected] or 530-747-8052.