When the Spanish settled the San Joaquin Valley in the late 1700s, it is commonly believed that they inadvertently introduced nonnative grass seeds, which likely hitched a ride overseas in the fur and bowels of their livestock. Eventually, the Mediterranean grasses such as red brome and wild oats came to dominate much of the regionto the detriment of native flora and fauna.
Ironically, cattle are now helping undo some of the ecological havoc they may have originally helped create. While current grazing practices are often associated with habitat destruction for many species, the federally endangered bluntnosed leopard lizard is not among them. In an unusual twist, grazing may help clear a path toward recovery for the reptile.
Cattle grazing helps open up areas for the lizard to travel and feed, says Nick Stanley, a deputy project leader at Kern National Wildlife Refuge Complex. When the grasses get really dense, thats a big problem for the lizard, which is desertadapted, because it gets caught up and makes for easy prey by snakes, raptors and other predators.
Stanley is charged with monitoring cattle grazing on about 6,000 acres at Pixley National Wildlife Refuge, part of Kern Refuge Complex. He conducts monthly checks and cattle counts throughout the grazing season, from November to April, and an endofseason evaluation. With a handful of ranchers who pay a fee to use the acreage, the number of cattle clearing the grass ranges from 70 to 800.
And those ranchers are pleased to be able to maintain a tradition that predates the refuges establishment in 1959.
Our families have been grazing cattle on whats now refuge land since 1938 or 39, says rancher Stanley White. Now it supplements other grazing lands we have, and it helps keep the land in control for the bluntnosed leopard lizard.
The diurnal reptile is endemic to the semiarid grasslands, alkali flats and washes of central California. It is a large lizard: three to five inches long (excluding tail), with a triangular head, truncated snout, rounded body, granular scales and a tail longer than its body. It prefers flat, open spaces for running.
Indeed, the traditional grazing is considered among the best methods to help the lizard as well as two other endangered speciesthe Tipton kangaroo rat and the San Joaquin kit fox.
Mechanical removal of vegetation is just not economically feasible, and, besides, it would be too intrusive to the habitat since the lizard burrows close to the ground surface says Stanley. And prescribed burns are not a good option since we have air quality issues in the valley as it is.
Grazing is a lowimpact way to clear the vegetation and reduce competition from invasive grasses with the native bunch communities.
But the lizard is not yet out of the woodsor, in this case, the grassaccording to Brian Cypher, an ecologist with the Endangered Species Recovery Program at California State University, Stanislaus. Cypher and other biologists with the university have been monitoring lizard populations at Pixley Refuge since 1993. They have found that lizard populations are dramatically affected by the growth of these nonnative grasses, especially after seasons of heavy rainfall.
Although the lizard is doing reasonably well in remaining areas with good quality habitat, the overall amount of that habitat is still declining annually, says Cypher. Natural lands are still being converted to industrial and urban uses, and farmlands continue to pose major problems. The valley produces more than 300 crops, but this is what has encroached so much on the natural landscape, and why we have so many listed species here.
Fortunately now, for at least some of these species, he says, land that isnt grown is pretty much grazed.
Ben Ikenson is a New Mexicobased freelance writer.