By ERIC CAINE
Sunday, June 26, 2005
When field biologist Linette Lina heard a singing male least Bell's vireo in the San Joaquin River National Wildlife Refuge on June 10, it marked a historic moment that continues to grow in significance. Shortly after Lina found the male vireo, she and her supervisor, Point Reyes Bird Observatory biologist Julian Wood, saw two adult least Bell's vireos feeding a fledgling. It appears the vireo may be expanding back into its historic Central Valley range after a decadeslong absence.
The least Bell's vireo is a drab little bird hardly more than four inches in length. But its humble appearance belies a mighty presence. Because it is a federally listed endangered species, the vireo can stall housing development, add millions of dollars of expense to road construction, and alter the best-laid plans of powerful men.
And while it may seem at first that the convergence of Lina and the least Bell's vireos in a national wildlife refuge is merely a happy accident, the first documented record of nesting least Bell's vireos in the Central Valley since 1928 involves far more than luck. Hard science, much of it funded by CalFed grants, played a major role in bringing the vireos back to their historic home.
Least Bell's vireos were once a common breeding bird in the Central Valley as far north as Red Bluff in Tehama County. The vireos disappeared from the valley when their riparian habitat gave way to agricultural and urban development. One mission of the San Joaquin River National Wildlife Refuge is to restore the kind of habitat that the vireos need for survival. Not coincidentally, another endangered species found on the refuge, the riparian brush rabbit, needs almost the same kind of habitat.
Refuge manager Eric Hopson has been involved almost daily in the restoration of the riparian forest that once sheltered both least Bell's vireos and riparian brush rabbits. Following advice from biologists at Point Reyes Bird Observatory, Hopson and the U.S. Fish and Wildlife Service have planted vegetation typical of the riparian forest understory along with tens of thousands of cottonwoods, willows and oaks.
As the result of studies provided by CalFed funding, observatory biologists like Julian Wood have been able to be very specific about the needs of least Bell's vireos.
"It was bird monitoring and research that led PRBO to recommend planting a dense native understory," said Wood. "By surveying birds and measuring vegetation, we can make associations between specific birds and habitat characteristics such as species composition, plant height, shrub cover, tree cover, etc. We recommended they include gum plant, mugwort and creeping wild rye in the understory."
It is thus by design, not coincidence, that a long line of mugwort stalks was in front of the cottonwood where Linette Lina first saw the singing male vireo. Mugwort, as the observator biologists well know, is often associated with the breeding of least Bell's vireos. And that same design has produced a manifold increase in nesting success of other birds within the refuge.
Protecting an endangered species like the vireo involves a special synergy from both public and private sectors.
From its inception, the San Joaquin River National Wildlife Refuge has been a cooperative project with a remarkable mix of contributors. Early on, Joe Long, founder of Long's Drugs, contributed more than $1 million to buy the first 800 acres for the project, and that money was augmented by a significant contribution from Modesto resident Don Lundberg via the Stanislaus Audubon Society. The National Audubon Society and U.S. Fish and Wildlife Service then combined efforts to establish the nucleus of the refuge on Chrisman Island. The refuge has grown slowly to 6,642 acres, with an approved boundary of 12,877 acres.
Much of the acreage is in the form of easements and agreements with farmers, who, despite the manifold problems stemming from mixing agriculture and wildlife, have been willing to work together to ensure the refuge's success. The families of Robert Gallo and the late Bill Lyons Sr. have been especially cooperative.
The result is a steadily growing refuge for tens of thousands of wintering waterfowl, including the formerly endangered Aleutian Canada goose, and a state-of-the-art restoration of the riparian forest so faithful to its natural design that it has received a seal of approval from a species absent from the area for almost 80 years.
When Lina was getting her degree in wildlife, fish and conservation at the University of California at Davis, she couldn't have imagined that she would someday find a federally endangered species that had been absent from its historic habitat for decades.
"All I knew was that I wanted to study animals," said Lina. "And I want my work to be a service to the world, by reducing or reversing the negative impact humans have made. Environmental workers are really just global janitors, in a sense. We're cleaning up a big mess."
Lina and all who've contributed to the growing refuge have obviously been doing something right. The evidence is in the winter flights of tens of thousands of Aleutian Canada geese, a growing population of riparian brush rabbits, and the exuberant song of a drab little bird, back at last where it belongs.
Caine, a Modesto resident and active birder, teaches in the humanities department at Merced College.
http://www.modbee.com/opinion/community/story/10764994p-11543340c.html