Recent accomplishments of CDFW's scientific community
For some public properties, livestock grazing can be an important land management tool to help maintain specific habitat conditions, control invasive weeds and reduce fire hazards. In areas invaded by non-native vegetative species, it is necessary to control vegetation height and density in order to keep habitats functioning for certain sensitive species. For instance, the burrowing owl requires low vegetation cover in order to forage for prey effectively and prevent predators from approaching unseen. Other species that have been known to benefit from managed livestock grazing include California tiger salamander, Yosemite toad and certain sensitive butterfly species.
Controlling the height and density of non-native annual grasslands through grazing has also been shown to help increase forage efficiency for many species of raptors, and it’s used as a tool in some areas of California to maintain sensitive vernal pool habitats.
For years, local, state and federal agencies, as well as non-government organizations, have utilized livestock grazing on public lands. It is important to have many tools available for habitat management because it can sometimes be complicated. Factors such as the presence of listed or protected species, compatible public land uses and erosion -- as well as other land management practices such as herbicide application, mowing and prescribed fires -- must all be considered.
CDFW’s Rancho Jamul Ecological Reserve in San Diego County recently hosted a livestock grazing workshop presented by Rancher to Rancher (R2R) program spokesperson Kent Reeves, and UC Davis researcher Dr. Christina Wolf. The goal of the R2R program is to provide information and educational resources to private ranchers about evolving livestock management practices intended to promote native ecosystem health, and therefore, more sustainable grazing programs. More than 40 participants, including local private ranchers and representatives from about a dozen government and non-government organizations attended the workshop. Participants learned about developing progressive management practices, such as the use of increased stocking densities for shorter, more frequent durations, in order to increase carbon sequestration in the soils. This method is currently being studied as a way of encouraging native grass species as well as combating changing climate conditions.
Restoration project area. CDFW photo by Andrew Hughan.
Yellow and orange indicate restoration areas at the Ocean Ranch Unit of CDFW's Eel River Wildlife Area.
How does one best go about making an already bountiful and bucolic part of the Golden State even better? Sometimes, perhaps paradoxically, it pays to look to the past in order to be forward thinking in the present.
CDFW, Ducks Unlimited, and many partners have undertaken the Ocean Ranch Unit of the Eel River Wildlife Area Integrative Ecosystem Restoration Project Planning Process to enhance the estuarine and coastal dune ecosystem of the Ocean Ranch Unit in Humboldt County
The approximately 2,600-acre Eel River Wildlife Area was acquired to protect and enhance coastal wetland habitat, and was designated as a wildlife area by the California Fish and Game Commission in 1968. The initial decision to undertake an estuary restoration-planning project began more than a decade ago. After several years of monitoring to gather necessary data, Ducks Unlimited completed a feasibility study, funded by CDFW’s Fisheries Restoration Grant Program and the California State Coastal Conservancy, in December 2015.
The primary goal is to restore and expand natural estuarine and dune ecosystem functions, including the recovery and enhancement of native species (including fish, invertebrates, wildlife and plants) and their habitats. These changes should also help mitigate current and future impacts of climate change. Sea level rise will likely result in saltwater inundation further upstream, which is expected to modify habitats (for example, the loss of tidal marsh migration inland) and the size and shape of the estuary.
The project has been a revelation for Michelle Gilroy, a CDFW district fisheries biologist who works primarily in Humboldt and Del Norte counties.
“For the first time in my 30-year fisheries career, which began in the Eel River watershed, I am achieving a long-time goal of mine: To envision, develop and work through to completion, or near completion, a large restoration project,” said Gilroy. “This exciting project and the extraordinary team I am so very fortunate to work with is making that dream a reality – and in the Eel River estuary, one of California’s largest estuaries. It is definitely one of the highlights of my career.”
Improving the connectivity of tidal and freshwater habitats, and controlling or eradicating invasive plants, are key goals of the restoration project.
A feasibility study guiding the project analyzed the potential for expanding tidal functions within 475 of the 933 acres of the unit to aide in the recovery and enhancement of estuarine habitat and native species. Restoration of these essential habitats is vital to the recovery of anadromous salmonid populations in the Eel River, as estuaries provide critical nursery and rearing conditions for juveniles prior to ocean entry.
The unit is located within the Eel River estuary, a mile and a half north of the mouth of the Eel River and approximately four miles northwest of Loleta. The unit is comprised of a diverse set of habitats, including coastal dunes, riparian woodlands, tidal mudflats, tidal slough channels, salt marshes and managed freshwater marshes.
Prior to second-wave human settlements, this portion of the estuary, then inhabited by Native Americans, consisted primarily of salt-marsh habitat dotted with areas of spruce and hardwood forest, and native grasslands. An abundant fishery, which included the prized salmon, along with native plants, provided sustenance for the Wiyot people who lived around Humboldt Bay and the estuary. As Euro-Americans settled this region, however, they largely drove the Wiyot people off their traditional lands and began to repurpose portions of the environment.
By the end of the 1800s, most of the salt marsh and forestlands were drained and converted to farm and grazing land. This conversion of tidal marshes to pastures was done with purpose – but such perceived progress carried an ecological cost.
The construction of levees and tide gates to drain salt marsh increased sedimentation, flooding, and the amount and diversity of habitat and food supply for fish and wildlife declined throughout the estuary. This degraded the prior functioning, highly productive estuary ecosystem. In addition, invasive species now threaten the diversity or abundance of native species through competition for resources, predation, parasitism, interbreeding with native populations, transmitting diseases, or causing physical or chemical changes to the invaded habitat.
Despite these declines, the Eel River delta, which includes the Eel River Wildlife Area, today continues to provide vital habitat for many aquatic and terrestrial organisms, including state and federally threatened and endangered fish, wildlife and plant species, and many state species of special concern. More than 40 species of mammals and 200 species of birds use the delta area and researchers have documented at least 45 fish species in the Eel River estuary alone.
The area provides essential spawning, nursery and feeding grounds to several commercially and recreationally important species, including Dungeness crab. Estuaries are among the most productive and diverse ecosystems in the world and are one of the preferred habitats for young Dungeness crabs.
Dungeness crabs use estuaries as critical nursery habitat in their juvenile stages, as not only a refuge from predation – particularly in estuaries with structural habitat such as eelgrass – but also because of the abundance and diversity of prey provided by estuaries. Dungeness crabs are opportunistic feeders – clams, fish, isopods and amphipods are their preferred food sources, as well as other Dungeness crabs. Their predators include those larger crabs, octopuses, and fish, including salmon, lingcod and various rockfishes.
Wildlife, of course, is not the only form of life to reap the benefits of this region, as humans enjoy a range of outdoor activities, including fishing, bird-watching, boating, hiking and hunting.
The project is expected to begin in the summer of 2019.
CDFW photos and map
Top photo: CDFW Senior Environmental Scientist Kirsten Ramey and Eric Ojerholm of the Pacific States Marine Fisheries Commission.
Partners, Funding and Staff
Ducks Unlimited, in partnership with CDFW staff, has recently secured project planning funds from the California Wildlife Conservation Board, and initial project implementation funds from the NOAA Restoration Center. To complete the restoration design and environmental compliance process, this second phase of restoration planning will consist of a continued CDFW and Ducks Unlimited partnership, with additional assistance from several local consultants and a Technical Advisory Committee (TAC). The TAC includes representatives from the U.S. Army Corps of Engineers, the Bureau of Land Management, U.S. Fish and Wildlife Service, National Marine Fisheries Service, California Coastal Commission, California State Coastal Conservancy, North Coast Regional Water Quality Control Board, California Sea Grant, California Trout, Humboldt County Resource Conservation District, Humboldt State University, Redwood Region Audubon Society, private landowners, and the Wiyot Tribe. Additional project partners include AmeriCorps, Tom Origer and Associates, Pacific Coast Fish, Wildlife and Wetlands Restoration Association, GHD Inc., H.T. Harvey and Associates, Moffatt and Nichol, Northern Hydrology Engineering, Pacific Coast Joint Venture, and the Pacific States Marine Fisheries Commission.
CDFW staff who have served on the project management team include Michelle Gilroy, Allan Renger, Scott Monday, Kirsten Ramey, James Ray, Mark Smelser, Gordon Leppig, Michael van Hattem, Jennifer Olson, Linda Miller, Clare Golec, Charles Bartolotta, Robert Sullivan, Tony LaBanca, Mark Wheetley, Scott Downie, Adam Frimodig, Jeff Dayton, Mike Wallace, Vicki Frey, John Mello, and Karen Kovacs.
Deep in the pickleweed in the San Francisco, San Pablo and Suisun Bays, the tiny salt marsh harvest mouse (Reithrodontomys raviventris) tries to avoid predators and compete with other species for prime habitat. Food and cover are abundant, but its overall habitat is shrinking as humans encroach upon its home range. In south San Francisco Bay alone, 95 percent of the historic salt marsh has been lost to industrial parks and subdivisions. Annual flooding in the winter can be perilous, too -- when vegetation is topped by rising tides, the mice must scramble to find taller vegetation or into upland habitat (grasses around the wetlands that don’t get flooded by the tides).
As part of the effort to monitor and conserve this state- and federally-listed endangered species, biologists conduct annual surveys of the salt marsh harvest mouse. The effort involves setting up traps stuffed with cotton batting and baited with birdseed and walnuts, taking measurements and collecting other data on the subjects that are captured. In some studies, the mice are fitted with GPS collars for tracking, or ear tags to help identify them upon recapture. In other studies, the biologists simply clip away fur on the mouse’s flank or neck – another method that helps them determine whether a mouse in a trap has crossed paths with them before.
Once a mouse’s measurements have been recorded, they are set loose to scamper back into the pickleweed. The data that’s been collected will later be entered into a larger database that will be accessible to researchers from multiple state agencies (CDFW, the Department of Water Resources), federal agencies (US Fish and Wildlife Service, the US Geological Survey), educational research institutions (UC Davis, CSU San Marcos, San Francisco State) and private industry.
By comparing population fluctuations and other data throughout the range, scientists hope to identify threats and increase their understanding of this rare rodent’s biology and behavior – ultimately helping to better inform future decisions on habitat management, restoration and enhancement efforts.
A California red-legged frog sits motionless at the edge of McClure pond at the Sparling Ranch Conservation Bank. Photo by Ashley Spratt/USFWS
McClure pond is one of the most productive California red-legged frog ponds at the Sparling Ranch Conservation Bank. Like many of those on Sparling Ranch, it was named after the family who homesteaded in site in the late 1800s. Photo by Ashley Spratt/USFWS
Since the mid-1980s, California has been using a system of conservation and mitigation banking to protect valuable natural resources and critical habitat for fish, wildlife and plants. These banks are generally large, connected, ecologically meaningful areas of preserved, restored, enhanced or constructed habitat (for example, wetlands) that are set aside for the express purpose of providing mitigation for project impacts. Conservation banks provide mitigation for impacts to listed species and habitats, while wetland mitigation banks primarily provide mitigation for wetland impacts. Together, they serve to prevent inadequate, fragmented reserves that can result when mitigation projects are carried out individually.
Banks work by establishing credits for sensitive species or habitats found on a given site. These credits can then be sold to developers or other project proponents who need to meet permitting requirements or are otherwise required to compensate for environmental impacts. For those parties needing to mitigate for project impacts, banks serve to streamline the regulatory process by providing a pre-established mitigation site that the regulating state and federal agencies have already confirmed will provide adequate and appropriate mitigation for certain habitats or species. By mitigating at a bank, project proponents can avoid the time and cost of searching for a suitable mitigation site and protecting it in perpetuity themselves.
In order for the banking system to be effective, state and federal agencies must work closely together to align processes and practices. Since 1993, CDFW has been participating in the planning, review, approval, establishment, monitoring and oversight of 81 banks statewide. Other agencies that typically participate in the regulation and approval of conservation banks include the U.S. Army Corps of Engineers (USACE), U.S. Environmental Protection Agency (USEPA), Natural Resources Conservation Service (NRCS), U.S. Fish and Wildlife Service (USFWS) and the National Oceanic and Atmospheric Administration National Marine Fisheries Service (NOAA NMFS).
To read more about one of these successful partnerships, please visit USFWS’ newsroom.
Learn more about CDFW’s Conservation and Mitigation Banking program, on our website.
All photos courtesy of U.S. Fish and Wildlife Service.
Top photo: A herd of cattle graze atop a hillside at Sparling Ranch near Hollister, Calif. Photo by Ashley Spratt/USFWS.
CDFW’s Yolo Bypass Wildlife Area serves two critical – but sometimes competing – needs.
The 16,670 acres of riparian and agricultural habitat in Yolo County provide a refuge and an all-you-can-eat buffet for migratory waterfowl and resident wildlife to the west of Sacramento and the increasingly urbanized surrounding communities.
The wildlife area is also a key cog in the Sacramento region’s flood control system. In wet years, the vast flood plain accommodates massive water diversions from the nearby Sacramento, Feather and Yuba river systems to prevent flooding in populated areas and to relieve pressure on strained river levees.
With the drought-busting rains and snow received last winter, the wildlife area resembled an inland ocean for the thousands of daily commuters traveling the Interstate-80 Yolo Causeway, which crosses the northern edge of the wildlife area. The floodwaters stretched as far as the eye could see, reaching depths of 20 feet in some places, and submerging almost every natural feature underneath. The consequences were dire for wildlife unable to escape.
Pheasants, deer, raccoons, and small rodents of all kinds were among the victims. Some were overcome by the rising water, some starved while waiting out the floodwaters in trees or isolated patches of high ground, others were picked off by predators stalking the water line for fleeing prey.
As a result, efforts are now underway to help the area’s wildlife survive future flooding. The Yolo County Resource Conservation District has secured almost $700,000 in Proposition 1 state water project funds to build two wildlife escape habitat corridors and a demonstration garden over the next four years. The project includes partnerships with CDFW, Yolo Basin Foundation, Center for Land-Based Learning, Putah Creek Council, the United States Department of Agriculture’s Natural Resources Conservation Service and Point Blue Conservation Science.
The demonstration garden will serve as an educational component for visitors near the wildlife area’s entrance. Two other corridors in the southern end of the wildlife area will stretch more than 5 miles total and include 22 acres of native grass seeding for nesting and cover. The corridors will run parallel to the Putah Creek channel, which is the only existing natural escape route now on the refuge.
“These corridors are basically like wildlife roads,” said Jeffrey Stoddard, the Yolo Bypass Wildlife Area manager for CDFW.
The floodwaters advance slowly enough that even the smallest animals can escape, Stoddard explained, provided they head in the right direction and don’t get exposed to predators along the way.
“We have blocks of escape habitat now, but we will be creating connectivity, moving animals from the east side that is deeper to the west side that is higher ground,” he said.
The corridors will consist of a mix of flood-tolerant native shrubs, grasses and forbs that will provide escape routes to high ground, protection from predators, food, and good habitat year-round.
The corridor work began in June with Putah Creek Council student interns collecting wild rose, red stem dogwood and coyote brush clippings for propagating and use as plant stock for the wildlife corridors.
Photos courtesy of CDFW, the Putah Creek Council and the Yolo County Resource Conservation District. Students pictured are interns from the Putah Creek Council’s One Creek Restoration Internship program.
Fate has not been kind to the San Joaquin kit fox (Vulpes macrotis mutica).
Shrinking habitat caused by urbanization and agricultural expansion landed this Central Valley native on the federal Endangered Species List decades ago. California’s total population of San Joaquin kit foxes may now be down to a few thousand animals. To make matters worse, its favorite food, the kangaroo rat, is likewise endangered as the desert habitat it prefers continues to disappear.
Wildlife biologists took heart, however, in a population that seemed to be thriving within the city limits of Bakersfield. Unlike San Joaquin kit fox populations in other parts of the Central Valley range, the Bakersfield foxes adapted quite nicely to urban life. Their number – estimated between 200 and 400 animals – has evidently seemed to be holding steady and possibly increasing.
Their cute and cuddly appearance make them popular with city residents. Earlier research showed the population was healthy and genetically robust. Wildlife biologists were counting on those urban foxes to ensure the species’ survival should kit fox populations completely collapse elsewhere.
Today, those Bakersfield kit foxes are under siege, suffering from an outbreak of highly infectious sarcoptic mange. Mange – a skin condition caused by parasitic mites -- leads to hair loss, open wounds from scratching and, ultimately, death. The first case was detected among the kit fox population in March 2013, and since then, more than 200 cases have been documented. The epidemic has grown worse every year.
Given the importance of the Bakersfield population, CDFW, the U.S. Fish and Wildlife Service, the California State University, Stanislaus, the University of California, Davis (UCD), and various nonprofit wildlife groups have all joined forces to combat the mange.
Jaime Rudd, an environmental scientist in CDFW’s Wildlife Investigations Lab in Sacramento, is leading CDFW’s efforts while simultaneously writing her UCD Ph.D. dissertation on the outbreak. Rudd is researching ways to prevent mange from spreading to healthy animals, and assisting Stanislaus State’s Endangered Species Recovery Program with trapping and treating diseased foxes.
Severely diseased kit foxes are trapped and transported to the California Living Museum, a Bakersfield wildlife rehabilitation facility and zoo. There, the kit foxes are hospitalized, given life-saving antibiotics and fluids and treated with a topical pet product that kills the mites. The foxes often need months of treatment before they are healthy enough to release. And although the intervention saves individual lives, the process is costly and time-consuming – and doesn’t prevent the treated fox from getting mange a second or third time.
Rudd is making good use of her undergraduate degree in molecular biology, analyzing the DNA of the mites to see if they might be related to those in dogs and coyotes, which could be spreading the mange to the foxes.
“Essentially, we want to look at their molecular signature to see if these mites are related,” Rudd said.
Rudd is studying a group of wild kit foxes living on the CSU Bakersfield campus, which no doubt are supplementing their diet with burger bits and pizza crusts discarded by college students. Rudd is monitoring the group with trail cameras, outfitting some foxes with radio tracking collars and others with the type of preventative flea and tick collar you might use on a pet dog or cat.
“We want to evaluate the efficacy of these collars,” she said. “If they’re only going to work for two months, the collars won’t help us slow down the spread of mange, so is it really worth the effort of putting them on? But if they’re going to work for five months or more, then it might be worth the effort.”
If there is any hope sustaining Rudd and her colleagues in this important, though often disheartening, work, it’s this: “The fact we are not seeing mange in the outlying populations is cause for optimism,” she said. “If nothing else, we can at least try to keep it from leaving the city.”
A tiny, endangered mammal is the subject of an extraordinary conservation effort near the communities of Shoshone and Tecopa in Inyo County.
The Amargosa vole is unique to the Mojave Desert, and today, scientists estimate there are only about 500 remaining in the wild. Though the Amargosa vole is rarely seen by humans, biologists recognize that it is a key link in the native food chain. Predators, including raptors and water birds, share the desert marshes where they live, and the extinction of the Amargosa vole would have a ripple effect on these and many other species as well.
For a year, a scientific team consisting of CDFW, UC Davis and US Geological Survey biologists have conducted intensive research into the life cycle of this little vole. The team visited every marsh that potentially could be inhabited by voles – they mapped the marshes, assessed habitat quality, and determined whether or not voles were present. In a subset of larger marshes the team conducted more detailed assessments of water inflow-outflow, soil moisture and vegetation, and captured voles to estimate local population numbers, assess the health of the voles and take samples for disease and genetics studies. In addition to the hands-on study in the desert, they also studied satellite data to track the amount of vegetation and water in the area over a period of time. A grim picture emerged of a habitat range in decline, due in large part to climate change and human modification.
Some of the findings included:
Scientists believe that the network of springs and marshes in the vole’s natural range has been so extensively modified by humans that the vole’s future existence will depend almost entirely on whether humans continue to supply water where and when needed. They found evidence to support this, as an intensive restoration effort at one of the largest marshes showed signs of successfully supporting and sustaining voles.
The report authors identified several specific measures that could be taken to increase vole habitat and improve their chances of survival – including reconfiguring water inflow and outflow, changing elevations and planting vegetation that would enhance existing marshes and/or better connect adjacent marshes.
This study is part of a larger long-term effort to secure a future for the Amargosa vole and the unique marsh ecosystems it depends upon in the Mojave Desert. In late 2014 vole numbers became so low that scientists initiated a captive breeding program at the UC Davis School of Veterinary Medicine to reduce the risk of extinction. Today more than 100 voles are in the captive colony at UC Davis – providing a potential source of animals for release into restored habitats, and an important insurance population to prevent extinction.
Photos by Don Preisler/UC Davis School of Veterinary Medicine
to receive Science Spotlight and Featured Scientist articles by email