Future no longer on the edge for three endemic and endangered species from the Eastern Sierra’s Owens Valley
The story of how humans have had a nearly catastrophic impact on an environment followed by a coordinated intervention to prevent the cataclysmic results is a far too common theme within the field of wildlife conservation. It happens at worldwide levels all the way down through national environmental issues and down further to regions within California. Three fortuitous species endemic to the eastern Sierra’s Owens Valley continue to survive thanks to timely action by numerous organizations during recent decades.
The Sierra Nevada bighorn sheep, the Owens pupfish and the Owens Valley checkerbloom remain listed as endangered species, but their continued existence is no longer in serious peril. Recovery programs spearheaded by environmental scientists from the California Department of Fish and Wildlife (CDFW), in association with other agencies and individuals, are achieving stated goals and ongoing success.
Spread out along the eastern side of the Sierra Nevada, the Owens Valley appears as an expanse where time has stood still. The vast landscape measuring 100 miles long and between 6 to 18 miles wide remains one of the least populated in the country. The valley covers about 3,330 square miles and carries a population density of 5.25 people per square mile, according to the U.S. Census Bureau. Ranked by population density with other states, the valley falls somewhere between Wyoming’s wide-open range with six people per square mile and the nation’s northernmost state, Alaska, with just 1.3 people per square mile.
The valley floor rises about 4,000 feet above sea level, flanked by the Sierra Nevada to the west and the White and Inyo mountains to the east. Steep granite peaks rise dramatically on both sides with the crests reaching more than 14,000 feet. Geologists consider the Owens Valley one of the deepest valleys in the United States.
Highway 395 dissects a north and south thread through substantial plains of uncultivated lands that appear untainted by human interference. The towns are small, few and far between. With such a quiet bucolic appearance, the valley appears capable of maintaining the equilibrium of its natural environment. Unfortunately, this is not the case, and the consequences of human activity have had far-reaching effects.
Early settlers came in search of wealth they thought would come through a boom in mining or fertile lands for homesteads. They brought with them non-native plants and animals that impacted the sustainability of native species. An even more significant impact to the area came from the export of water to the bulging Los Angeles area. The shift in water rights drained the underground aquifer and created serious consequences for the native plants and animals of the Owens Valley.
SIERRA NEVADA BIGHORN SHEEP
Many wildlife biologists and scientists who work on the conservation of Sierra Nevada bighorn sheep (Ovis canadensis sierrae) believe the species has roamed the Sierra Nevada for more than 300,000 years. Because of the gradual deterioration of populations, a decade ago CDFW scientists began a recovery program for the critically endangered species. Today, scientists review the work that has been expended and feel secure in calling the effort a success.
One of those involved with the species is senior environmental scientist Tom Stephenson, a wildlife supervisor for the northern portion of CDFW’s Inland Deserts Region and the program leader for the recovery program. While it is impossible to know how many sheep traveled across the high mountains in prehistoric times, Stephenson knows the population numbers were thriving in the mid-19th century, when human habitation in the Eastern Sierra was increasing and encounters with these animals were frequent. As late as 1870, evidence suggested that at least 1,000 animals across a number of healthy herds inhabited a huge swath of the high Sierra, from Sonora Pass south to Olancha Peak.
That healthy state of affairs for the bighorn reversed over the next 100 years as the population was almost wiped out. Unregulated hunting of this gregarious animal and the rampant spread of disease carried by domestic sheep brought this species to the brink of extinction. The worst of the illnesses came through the transmission of pneumonia in the late 1800s, and by 1970 only two small herds had survived, one in the vicinity of Mount Baxter and the other near Mount Williamson.
Despite efforts by CDFW to reestablish bighorn herds in other historic habitats, the total population of the Sierra Nevada bighorn sheep continued to decline. In 1995, it hit a low of 105 individuals. The U.S. Fish and Wildlife Service listed the animal as endangered under the Endangered Species Act (ESA).That same year, California upgraded its listing from threatened to endangered under the California Endangered Species Act.
A structured recovery effort was implemented under the joint leadership of both state and federal fish and wildlife organizations. The Sierra Nevada Bighorn Sheep Recovery Program formed through a collaboration with the National Park Service, Bureau of Land Management, U. S. Forest Service and the USDA Wildlife Services.
The program established three measurable goals:
- Ensure at least 305 females are among the herds to ensure sustainable growth.
- A dozen viable herds must be distributed within specific areas in historic ranges, known as herd units, in order to minimize any natural catastrophic impact on the population as a whole.
- Prevent contact between bighorn sheep and domestic sheep and goats to stem the spread of communicable diseases.
When the objectives are met, the species can be downlisted from an endangered to a threatened status on the ESA lists. Stephenson said the species had grown close to the goals required until the past year. The winter brought record snowfall to the Sierra Nevada and the severity of the extreme conditions resulted in fatalities among the herds.
“It knocked some of the populations back by about 20 percent, but all the populations persisted,” Stephenson said. “Healthy populations can bounce back, which is why it is imperative that contact with domestic sheep and goats is all but eliminated if this species is to survive and thrive.”
He believes it fortunate that the harsh winter occurred prior to any decision on a shift for the species from endangered to threatened. It tested the basis on which the goals of the recovery program were set and provided justification.
Still, even with the winter’s setback, the recovery program has reached two of the goals. Head counts indicate that viable herds do occupy the specified herd units that had been indicated. The second met goal came as a victory in the Legislature earlier this year after a county board of supervisors rejected a request to renew a grazing lease for domestic sheep.
The decision by the Mono County Board of Supervisors came after presentations from CDFW and the U.S. Fish and Wildlife Service that presented scientific evidence of the damage caused by the grazing habits of domestic sheep within a mile of habitat for the endangered Sierra Nevada bighorn sheep. The presentations and decision by the Mono County supervisors drew praise from allies, such as the Sierra Nevada Bighorn Sheep Foundation.
Stephenson cautioned against any suggestion that the bighorn sheep population has returned to its former glory. Other factors like predation by mountain lions or natural disasters from avalanches to limited food sources can contribute to declines in populations. “These do pose a threat by virtue of the fact that herds are relatively small and the loss of just a few animals can potentially be significant.”
But such potential pressures pale in comparison to what would happen to populations if a virulent disease moved through a herd. An event like that, experts agreed, would likely annihilate the bighorn population. The risk of such an event highlights the importance of the preventive decision made by Mono County supervisors.
Today, members of the recovery program labor in the bitter winter and broiling summer of the High Sierra to conduct population surveys of all bighorn herds. They determine the nutritional status of more than 200 bighorn sheep as well as monitor the survival and habitat-use patterns of the animals. They collect data stored on more than 45 global positioning system collars as the collars fall from the animals. They also draw from a 40-year-old study that started with the earliest recovery efforts. The feeling is that when they analyze the decades-old study next to the newest information from the field, it enhances the overall depth of information they have on wild sheep, something more valuable as it reveals details about their habits and habitats.
Today more than 600 animals live in these mountains with herds covering an area larger than 1,500 square miles from west of Bridgeport to west of Olancha.
Habitat occurs on the eastern slopes of the range from as low as 4,700 feet in elevation to as high as 14,000 feet. The animals prefer open areas with high visibility characterized by steep slopes and sparsely vegetated rocky outcrops. They rely on keen eyesight and a supreme ability to reach high rocky perches quickly to escape predation.
During the winter, people in Owens Valley might see the sheep at lower elevations at the north end of the valley, near Bishop. The winter range of the Wheeler Ridge herd comes relatively close and the landscape allows the best chance for catching a glimpse of the remarkable animals.
The recovery program appears on track to meet its goals for downlisting the species. Anticipation remains high for meeting the ultimate goal of delisting the species.
“They are using more habitats than we previously knew they were using,” said Stephenson. “Some are living year-round in alpine conditions.”
The information suggests estimates of population numbers prior to the decline was underestimated. Stephenson said, “I’d prefer to say thousands,” of these animals may have inhabited the historic range of the eastern slopes of the Sierra Nevada.
Fish specialist Steve Parmenter is a senior environmental scientist with CDFW’s satellite office in Bishop. Many considered him an Owens pupfish expert and he agrees with the most recent estimate of evolutionary history, accepting the species’ age and believing it began life in what is now the Owens River Valley.
The Owens pupfish was abundant throughout the Owens Valley until 1940, when the species was believed extinct. Measuring less than 2½ inches in length—with an occasional large male a little longer—pupfish males turn a bright blue in color during spawning. The distinctive behavior of ‘tail wagging’ during courtship and contest resembles the action of a playful puppy—hence the name pupfish.
The Owens pupfish is one of the nine western pupfish clade (organisms that evolved from a common ancestor) that live separated from one another in isolated ponds within a huge area spanning much of the west and southwestern North American continent. Exactly how the pupfishes diversified is not clear.
According to the U.S. Geologic Survey, the Sierra Nevada and Owens Valley are in one of North America’s youngest geologic regions that stretches across much of California, Oregon and Washington. Consequently the geologic connection between the ancient river basins of the western continent has been obscured by the passage of time and the birth of new mountain ranges.
Scientists have theorized that given their tendency to live in low-gradient, valley-floor habitat, pupfish migrated during periods of transient surface water connections. Eventually, when these water connections were either disrupted or dried up, populations of the ancestral fish were entirely separated from one another and evolved into the nine species still in existence today.
“They can truly be said to be as old as the hills,” said Parmenter.
Over decades, people introduced non-native trout, largemouth bass and bullfrogs to the waters of Owens Valley. The reasons varied, but they were brought primarily for bait, sport fishing and mosquito control. Pupfish became an easy source of food for these voracious eaters. In less than 30 years, an ancient species that had thrived for millions of years was largely eliminated.
“One bass can decimate a population of thousands of pupfish over a period of months, and a handful of bass can eliminate them in weeks,” Parmenter said.
Through the mid-20th century, scientists believed the Owens pupfish no longer existed. It wasn’t until 1964 that three men proved differently. Ichthyologists from the University of Michigan and the Scripps Institution of Oceanography traveled to California and joined with a veteran CDFW fishery biologist Phil Pister to learn what happened. Ichthyology is the scientific study of fish, the branch of zoology devoted to the understanding of all three varieties, bony, cartilaginous and jawless fish. Pister is the fisheries biologist who Parmenter eventually replaced. Many of the practices of conservation that Pister had a hand in developing, Parmenter continues today.
The university scientist, Dr. Robert Rush Miller, had conducted dissertation research on pupfish north of Bishop and with his Scripps Institution colleague, professor Carl Hubbs, sought evidence that a remnant population might have survived.
They had. And the three scientists brought the discovery of about 200 Owens pupfish in Fish Slough Ecological Reserve to the scientific world.
The discovery proved a game-changer for scientists, conservationists and CDFW’s fisheries branch. Before the nation developed its rules designed to protect critically imperiled species from extinction, the federal government labeled the Owens pupfish endangered. Eventually fisheries biologists would design refuges within suitable habitat and gradually reintroduce the fish into the waters. But in the early years after the discovery, the chances of the species actually going extinct remained possible.
In 1969, about 800 of the descendants of the rediscovered population survived in a reed-choked pond that was drying up. Pister made the decision to move them.
He collected and carried the population in two buckets and relocated them to five small ponds. He had found suitable habitat in the valley where consistent spring flows and groundwater provided a sustainable environment. Hardly a sophisticated plan of action, it nonetheless succeeded, and the subsequent survivors became the founding population of all remaining Owens pupfish.
CDFW staff and volunteers today continue regular patrols of these refuges to check on conditions and maintain the environments. For these professionals who take seriously the task of allowing this species to rebound, it can be disturbing to find that ill-informed anglers still release predatory fish into the Owens Valley waterways. Recently, environmental scientists recovered a pair of piscivorous pet turtles that had been abandoned in a protected pond.
Parmenter described protecting the pupfish is a “shell game” of moving and transplanting fish from site to site. “They have tremendous biotic potential,” he said. “You put them in a place without predators and they will expand their numbers. In a year’s time, they can raise two and maybe three generations.”
Pupfish have a high tolerance for changeable water temperatures and conditions. They survive in waters that will reach up to 91degrees in summer, yet are just as lively under layers of ice during winter. In some ponds the water has lowered levels of oxygen, which increases the salinity level four times that of the ocean, and yet scientists have seen the fish survive. What scientists have learned is that against the odds— but with the help of its protectors—the pupfish is a survivor.
OWENS VALLEY CHECKERBLOOM
The first recorded instance of the Owens Valley checkerbloom (Sidalcea covillei) came in 1891 by F.V. Coville on an expedition to Death Valley.
The flower was first described as a species in 1914 and its taxonomic status has remained unchanged since.
The perennial herb, with stems between 8 to 24 inches, tops off with a five-petal pinkish-purple bloom. It occurs solely in the greater alkali meadow environment found in the valley and remains highly restricted within the specialized habitat with very limited distribution. By 1979, it was thought to be near extinction and was listed as endangered un- der the California Endangered Species Act.
Alkali meadows are a major vegetation type in the Owens Valley. They sustain a diversity of animals, birds and other plants, including the rare checkerbloom. They are probably the most distinctive native plant habitat across the valley. Scattered along the 75 miles of the Owens River drainage, the alkali meadow habitat is a groundwater-dependent ecosystem that is itself under considerable threat. Overgrazing by cattle and extensive groundwater pumping has dried up vast tracts of alkali meadows.
These fragile meadows are sometimes seen by visitors as a collection of weeds or referred to incorrectly as sagebrush. In addition to the checkerbloom, a healthy meadow hosts irises, lilies and broad-leaved herbaceous plants. Grasses and native shrubs such as rabbitbrush, Nevada saltbush, greasewood and the ubiquitous sagebrush are all cohabitants in this diverse ecosystem.
In 2011, the U.S. Fish and Wildlife Service awarded a $200,000 grant to the Bishop Paiute Tribe for a conservation area management project as part of an ongoing tribal wildlife program. According to the federal agency, “The grants provide technical and financial assistance for the development and implementation of projects that benefit fish and wildlife resources and their habitat, including non-game species.”
One of the goals of the grants is to “reintroduce, sustain and nurture populations of species of concern of Owens Valley checkerbloom.” The plan offers a bonus, of sorts, as another goal is to “introduce new populations of the endangered Owens pupfish.”
The grant increased management capacity through enhanced partnerships to protect the many endemic and endangered species in this region.
In a majority of wild lands across American landscapes, the impact to the environment left by humans has been a major down- grade. In its favor, the Owens Valley and the mountain ranges that frame it have escaped California’s population surge and the adverse effects left behind by such extensive development.
With more than 10,000 square miles in its boundaries, Inyo County represents California’s second largest county. Private landowners hold less than 2 percent of the more than 300,000 acres of real estate that encompasses much of the valley floor. Federal agencies like the U.S. Forest Service, National Park Service and Bureau of Land Management own about 91 percent, while the state takes 3.5 percent and the Los Angeles Department of Water and Power takes percent. The county and other local agencies, including tribal entities own the remaining .3 percent.
While encroachment into the Owens Valley’s sensitive natural habitat has been curtailed, the exploitation of the water resources by the coastal regions of southern California has had a lasting impact on the region—arguably much of it negative.
Still, it has perhaps had a salubrious effect as huge tracts of land remained undeveloped. These landscapes and their unique ecosystems, while threatened by the loss of water, are undergoing positive changes due to the foresight of the state and federal agencies to work collaboratively to care for the species within these environs. The futures of the Sierra Nevada bighorn sheep, the Owens pupfish and the Owens Valley checkerbloom are three that shine a light on wildlife restoration and conservation work in the Eastern Sierra.