Bring in the cows

Grazing may be the best hope for a threatened butterfly

  • A bay checkerspot butterfly on a tidy-tips wildflower on Coyote Ridge near San Jose, California.

    Thomas Nash
  • Conservation biologist Stuart Weiss has found that areas grazed by cattle for a short period, like those on his side of the fence, are better butterfly habitat than ungrazed areas like those across the fence.

    Thomas Nash
  • Cattle eat invasive grasses on one area of Coyote Ridge, before being moved on to another.

  • Native goldfields and poppies blanket Coyote Ridge above California Hwy. 101, where pollution helps invasive grasses thrive, if they're not kept in check by grazing.

    Thomas Nash
 

"There they are, the keystone herbivores!" shouts conservation biologist Stuart Weiss. Framed by the front window of his Toyota truck, a small herd of cattle can be seen grazing near the crest of Coyote Ridge, a craggy promontory of serpentine rock that towers over the city of San Jose, Calif., unofficial capital of Silicon Valley. Ten cows and as many calves turn to stare, then go back to cropping grass turned green by winter rains.

No, laughs Weiss, these are not the infamous hooved locusts, tramplers of wildflowers, creators of cowburnt wastelands. These are well-mannered cows that don't overgraze because they are regularly moved from pasture to pasture. As a result, Weiss says, the grass-nibbling they do is beneficial, not harmful. In fact, their presence in these rugged rangelands may well be the only thing standing between an iconic insect, the Bay checkerspot butterfly, and near-certain extinction.

An affable 6-footer who makes his living as an ecological consultant, Weiss has followed the declining fortunes of the Bay checkerspot ever since 1979, when he was a freshman at Stanford University. For the past decade, he has been sounding the alarm about what he now considers the most pernicious threat to the beautiful bug's near-term survival -- the unholy synergy between invasive grasses and urban smog.

Smog, Weiss explains, contains not just carbon dioxide, the gas that drives global warming, but also a cocktail of nitrogen-rich compounds. Swept by the winds onto nearby rangelands, these compounds act like spray-on fertilizer, encouraging the rampant growth of Italian rye, wild oats and soft chess. Left unchecked, these aggressive annuals quickly overrun low-lying native plants, including dwarf plantain, the chief food source for Bay checkerspot caterpillars.

And this, of course, is where the cows come in.

To illustrate the point, Weiss parks his truck and hikes into a meadow the bovines have recently mowed. All around him, wildflowers are in various stages of bloom: California poppies, goldfields, red maids, tidy-tips, desert parsley, wild onion. Best of all is the silvery carpet of dwarf plantain that unfurls underfoot, "the most important plant in the world," Weiss calls it. Sure enough, in the midst of the plantain lies a fuzzy caterpillar, enjoying a postprandial nap.

"Isn't that the California lifestyle for you!" Weiss beams. "First you enjoy a salad of tender young greens, then you bask in the sun!"

Suddenly, the 49-year-old scientist starts to run, following a fluttering in the air, and just as suddenly he skids to a stop. In front of him, on a lichen-speckled rock, an adult Bay checkerspot spreads its wings to reveal a mosaic of orange and white set off by vivid black. Soon, thousands more like it will emerge from their tent-like chrysalises, and, over the course of a lifespan measured in days, they will mate, lay their eggs and die.

Were it not for the cows, Weiss says, these exquisite, ephemeral creatures could easily be the last of their kind.

Following a staircase of hoof prints, Weiss climbs to the top of a rocky knoll that affords a sweeping view of the valley and coastal mountains. Overhead a black-shouldered kite hovers; beneath us, a Black Angus cow and her calf duck into an oak-shaded ravine. Settling down on an inviting patch of ground, Weiss unstraps his backpack and pulls out a sandwich, a bar of chocolate and a thermos of green tea.

For a while we sit in silence, staring down at the cars and trucks streaming along U.S. Highway 101 a thousand feet below. Not visible from here is the full network of roads that connect San Jose and other Silicon Valley cities to the San Francisco Peninsula. Despite tighter emission controls, Weiss says, the vehicles that ply this congested corridor -- over 100,000 per day on U.S. 101 alone -- generate a significant amount of pollution, which the winds then lob onto Coyote Ridge.

High Country News Classifieds
  • DEPUTY DIRECTOR
    The Methow Valley Citizens Council has a distinguished history of advocating for progressive land use and environmental values in the Methow Valley and Okanogan County...
  • ACTING INDIGENOUS AFFAIRS DESK EDITOR
    High Country News is seeking an Acting Indigenous Affairs Editor to oversee the work of our award-winning Indigenous Affairs Desk while our editor is on...
  • GRANTS PROGRAM DIRECTOR
    The Cinnabar Foundation seeks an enthusiastic, team-oriented and knowledgeable Grants Program Director to work from their home in Montana. Established in 1983, the Cinnabar Foundation...
  • ARTEMIS PROGRAM MANAGER
    The Artemis Program Manager will work with National Wildlife Federation sporting and public lands staff to change this dynamic, continue to build upon our successful...
  • ALASKA SEA KAYAK BUSINESS FOR SALE
    Well-known and successful sea kayak, raft, hike, camp guiding & water taxi service. Sale includes everything needed to run the business, including office & gear...
  • MEMBERSHIP AND EVENTS PROGRAM COORDINATOR
    Great Old Broads for Wilderness seeks a detail-oriented and enthusiastic Membership and Events Coordinator to join our small, but mighty-fun team to oversee our membership...
  • PROGRAM DEVELOPMENT FACILITATOR
    ABOUT THE HIGH DESERT MUSEUM Since opening in 1982, HIGH DESERT MUSEUM has brought together wildlife, culture, art and natural resources to promote an understanding...
  • LAND STEWARD, ARAVAIPA
    Steward will live on-site in housing provided by TNC and maintains preserve areas frequented by the visiting public and performs land management activities. The Land...
  • DEVELOPMENT WRITER
    Who We Are: The Nature Conservancy's mission is to protect the lands and waters upon which all life depends. As a science-based organization, we create...
  • CONNECTIVITY SCIENCE COORDINATOR
    Position type: Full time, exempt Location: Bozeman preferred; remote negotiable Compensation: $48,000 - $52,000 Benefits: Major medical insurance, up to 5% match on a 401k,...
  • EXECUTIVE ASSISTANT
    ArenaLife is looking for an Executive Assistant who wants to work in a fast-paced, exciting, and growing organization. We are looking for someone to support...
  • EXECUTIVE DIRECTOR
    The Mountain Lion Foundation is seeking an Executive Director. Please see our website for further information - mountainlion.org/job-openings
  • WASHINGTON DC REPRESENTATIVE
    Position Status: Full-time, exempt Location: Washington, DC Position Reports to: Program Director The Western Organization of Resource Councils (WORC) is seeking a Washington, DC Representative...
  • REGIONAL CAMPAIGN ORGANIZER
    Position Title: Regional Campaign Organizers (2 positions) Position Status: Full-time, exempt Location: Preferred Billings, MT; remote location within WORC's region (in or near Grand Junction...
  • STAFF ATTORNEY
    Western Watersheds Project seeks a Tenth Circuit Staff Attorney to bring litigation in the interests of protecting and restoring western watersheds and wildlife, particularly focused...
  • DEVELOPMENT DIRECTOR
    Driggs, ID based non-profit. Full time. Full job description available at tvtap.org. Submit cover letter and resume to [email protected]
  • ENVIRONMENTAL AND CONSTRUCTION GEOPHYSICS
    - We find groundwater, buried debris and assist with new construction projects for a fraction of drilling costs.
  • SPRING MOUNTAINS SOLAR OFF GRID MOUNTAIN HOME
    Located 50 miles northwest of Las Vegas, Nevada in the pine forest of Lee Canyon at 8000 feet elevation. One of a kind property surrounded...
  • MAJOR GIFTS MANAGER - MOUNTAIN WEST, THE CONSERVATION FUND
    Cultivate, solicit and steward a portfolio of 75-125 donors.
  • NATURE'S BEST IN ARAVAIPA CANYON
    10 acre private oasis in one of Arizona's beautiful canyons. Fully furnished, 2123 sq ft architectural custom-built contemporary home with spectacular views and many extras....