Saving the declining populations of Mojave desert tortoise is a big challenge. But scientists think that raising newborn “hatchling” tortoises in a controlled environment in the Mojave National Preserve for a year, then releasing the juvenile tortoises into the wild, may help save this threatened species.
The protected tortoises — which live up to 80 years and can go without water for a year — have existed for eons, but are now being decimated by habitat loss and predation. Professor Brian Todd, in the Department of Wildlife, Fish and Conservation Biology at UC Davis, worries that the increasing use of Southern California deserts for solar and wind energy, will add to the loss of tortoise habitats, and add further pressure to regional wildlife habitats. While developing renewable energy to combat climate change is a good thing, in this case it impacts desert species and their habitats.
Ivanpah Desert Tortoise Research Facility. The new facility, located in the Mojave National Preserve, was designed for scientists to conduct research on juvenile tortoise survival. It was constructed largely by Chevron and Molycorp, and is managed by the National Park Service. Scientists from the University of California, University of Georgia, and elsewhere, are conducting a 15-year study to see if hatchlings released into the wild and/or relocated elsewhere can survive and reverse the population decline.
We can all keep our fingers crossed that this research will preserve desert tortoise populations, and serve as a model for conserving biodiversity.
- “Protecting the desert tortoise,” video of UC Davis researchers and desert tortoises.
- “Habitat selection, space use, and factors affecting recruitment of desert tortoises in the Mojave National Preserve”; Brian Todd website, UC Davis
- “Baby desert tortoises get a headstart in the Mojave,” by Andy Fell and Kat Kerlin, Egghead blog, UC Davis. With a video of tortoises and scientists.
- “Tortoise territory,” by Robin DeRieux, CA&ES Outlook magazine (see pages 2 and 10), UC Davis, spring/summer 2012.
- “Mojave National Preserve celebrates dedication of Ivanpah desert tortoise,” Mojave National Preserve website.
Sacramento River Delta Grown Agritourism Association map brochure invites, “Drive along winding rivers and sloughs in the heart of the California Delta; Visit quaint historic towns, shop at rustic farm stands or pick your own fresh fruit and vegetables; Taste Delta wines, picnic by the river, and enjoy the peaceful pace among generational family farms.”
Capay Valley Farm Trail Map lists more than 40 farms in the Cache Creek watershed, and explains, “Capay Valley is a remarkable stretch of fertile land and rolling hills, home to a host of small and mid-size farms, natural wonders, and outstanding events…”
The North Yuba Grown Farm Trail Map brochure encourages visitors to “Enjoy the Flavors of North Yuba … Some olive trees in the area are more than 100 years old, and are still producing excellent olive oils. The vines cultivated for wine are forced to dig deep for water and nutrients, resulting in smaller yields but expressing intense flavors.”
As Californians' interest in local food and farming increases, farmers in many parts of the state are finding ways to invite their urban and suburban neighbors out to the farms to taste, tour, play and learn. Three groups of growers, Capay Valley Grown in Yolo County, North Yuba Grown in Yuba and Butte, and Sacramento River Delta Grown in Sacramento County, have just published new farm trail maps that promote agritourism in their unique farming regions. The maps are part of a UC Small Farm Program project, funded by a CDFA Specialty Crop Block grant, called, “Building a Farm Trail: Developing effective agritourism associations to enhance rural tourism and promote specialty crops.”
The Sacramento River Delta group put on their Wine and Produce Passport Weekend in early August to debut their maps. North Yuba Grown is sponsoring the North Yuba Harvest Festival, to be held on September 27 and 28, and Capay Valley Grown is planning an Open Farm Day on October 5 this year. The groups of growers will have a chance to share their experiences with each other at a regional workshop in November, and with other California agritourism operators at a statewide agritourism summit to be held in April 2015.
The California Statewide Agritourism Summit, organized by the UC Small Farm Program as part of the same project, will bring together agritourism associations and others involved in California agritourism from throughout the state to learn from each other. The summit will include planning sessions for the continuation of statewide farm trail and agritourism association networking and skill-sharing. For more information, please click here or contact UC Small Farm Program Agritourism Coordinator Penny Leff, (530) 752-7779.
Introduced predatory and competitive fish species and low water flows in the hitch's spawning grounds have combined with other factors to throw hitch populations into decline, prompting its designation as a threatened species. With the new status, agencies can now solicit funds for stream and habitat improvements and any changes to the shoreline, tributaries and lake may only be made after carefully studying the potential impact on Clear Lake hitch.
“Anytime an animal gets listed, I believe it's an admission of failure on the part of society,” said Greg Giusti, UC Cooperative Extension natural resources advisor in Lake County. “We've been asleep at the switch.”
Giusti is mobilizing efforts to help the local residents, anglers and farmers deal with outcomes of the new designation.
Scientists determined the Clear Lake hitch was a distinct species in 1973. There are hitch in other Northern California lakes and waterways, but differences suggest the Clear Lake hitch took its form after geologic forces separated the lake from the Sacramento River watershed thousands of years ago.
The Clear Lake hitch spawn in creeks and streams in late winter and early spring. Eggs hatch in about seven days and a week later the free swimming young begin moving down stream. For 80 days the fish stay in marshy areas at the mouths of streams, feeding heavily on rice fly larvae. At about 2 inches in length, they move away from the shore into deeper water and, when mature, return to spawn in streams.
Pomo Indians traditionally harvested Clear Lake hitch in large numbers when free-flowing creeks and streams were teaming with spawning adults. The fish were dried and served as an important food source all year. Descendants of Native Americans wish to continue the practice.
According to Peter Moyle, professor in the Department of Wildlife, Fish and Conservation Biology at UC Davis, the fish were among the last native species in Clear Lake to be doing reasonably well until the early 1970s when three alien fishes became abundant in the lake - Florida largemouth bass, Mississippi silverside, and threadfin shad.
“The bass is a terrific game fish,” Moyle said. “The Florida bass was introduced to improve the fishery. However, they became very abundant and are voracious predators of hitch. Likewise, the silverside and shad likely prey on hitch larvae and compete with hitch for their zooplankton food.”
Clear Lake hitch have also been impacted by water extraction from the tributaries upstream, mainly for irrigation, plus the construction of bridges, dams and other structures in their spawning streams.
While in the past there were tens of thousands of Clear Lake hitch spawning in dozens of tributaries, in recent years, population has been reduced to a few thousand and they reportedly spawn in only two streams. Because of the low water flows in current drought conditions, Giusti said, there was virtually no Clear Lake hitch spawn at all in 2014.
"Drought and taxes have a lot in common. They are both facts of life that must be dealt with periodically, they are both pains in the neck, and they both carry serious consequences if we choose to ignore them." - Jeff Mosley, Extension Range Management Specialist, Montana State University, Bozeman.
As a result, producers over the years have developed strategies to cope with the inevitable effects of drought. Ranchers are tremendously affected by drought mainly because of their dependence on annual precipitation for forage production.
Drought affects ranchers through loss in forage production, water shortage, and higher prices and reduced availability of supplementary feed. In the past year alone, many workshops and web resources were put together to provide drought management tools and information for the ranching community. The Drought Management Workshop at the Sierra Foothills Research and Extension Center and the California Rangeland Watershed Laboratory website are two good examples.
Now may be the right time to look ahead and plan for the future. The two most important questions rangeland managers need to ask themselves are:
- What have we been doing well that we need to continue building upon?
- What changes do we need to make to improve future production, and maintain or improve resilience to future droughts?
This process can be daunting, but dividing the activities into short-term, medium-term and long-term categories may help make the planning process less overwhelming. This way, one can focus on a few activities at a time while building towards long-term resilience.
Short-term: The first year after a drought period, cow-calf producers will be focusing on rebuilding their herd. During this process, paying particular attention to herd genetics and health is critical. Rebuilding a herd after a severe drought may be a good opportunity to bring in new qualities that were previously missing. Examples of characteristics to consider include good mothering ability (weaning weight, early calving, calving ease), temperament, livestock that will not only survive, but thrive in your environment, animals suitable for your target markets and animals with a history of good health and management.
It may be a good idea to start slow with the herd-building process or stock lower than normal for stocker operations the first year after a drought. This is especially true for rangelands that had lower than the recommended residual dry matter (RDM) levels before the fall rains started. University of California researchers found that optimum RDM levels (old herbaceous plant biomass left before the fall rains) in annual rangelands tend to increase with slope and decreases with woody cover. Lower RDM is expected to result in lower than normal forage production and lower species richness. The first year after drought, ranchers may want to explore available drought or emergency programs (e.g. FSA programs) that may help in the process of rebuilding the herd or providing feed and water for their livestock.
Medium-term: Two to three years after drought, ranchers should continue building their herds, monitor rangeland condition and actively manage rangeland weeds, if any. During this period, livestock numbers can be increased to optimal levels because even annual rangelands that had lower RDM due to drought conditions are likely to be fully recovered from drought effects within three years. Starting or continuing a rangeland monitoring program to measure forage production and RDM is critical at this stage in order to generate information necessary to make management decisions.
Monitoring forage production, in the medium-term and eventually long-term, is important for setting conservative stocking rates. Weed management has to be one of the main priorities in any management programs, because drought conditions sometimes increase the risk for weed invasion. If left unchecked, weed invasion will reduce rangeland carrying capacity in the long-term by reducing rangeland nutritional value as weeds continue to replace preferred and more palatable species.
Long-term: The fourth year onwards is about building flexibility into the system to accommodate fluctuations in forage production over time that occur in these complex ecosystems. The more flexibility built into the system the more resilient the operation. A production system with different animal types, e.g. cow-calf and stockers, allows for more flexibility to increase livestock numbers during periods of good forage production and reduce numbers when drought conditions return. Going further to add other livestock species would make sense if conditions are ideal. This is the time to look for more options to increase grazing land, by leasing more land if available; and building relationships with suppliers of local agricultural bi-products that are good livestock feed. Alternative on-ranch enterprises like value-adding and agro-tourism could be options for some. Water availability in all pastures used during the dry season should be planned, to ensure reliable water is available for the livestock during dry seasons. Drought resilience tends to increase as a producer makes more effort to integrate drought management tools into the management plan.
California Animal Health and Food Safety Laboratory System at UC Davis School of Veterinary Medicine, provide this critical information to dairy and beef producers to keep their livestock healthy during the drought. Key threats to cattle include:
Water quality — Water is the most critical factor in the diet of food animals. When cattle don't drink enough clean and safe water every day, feed intake and productivity declines. Drought conditions can potentially affect all sources of water, including groundwater, but surface waters are especially vulnerable. It is important to frequently monitor water quality, especially as quantity becomes more limited, and test for basic water quality parameters such as total dissolved solids, sodium, sulfates, and nitrates/nitrites. Blooms of blue-green algae in water are also an issue. These cyanobacteria can produce toxins that can affect the liver and nervous system. Depending on the specific toxin and amount ingested, animals may die suddenly, or suffer from weakness, staggering, or photosensitization.
Feed quality and nutritional deficiencies — Drought conditions frequently result in the need to feed poor quality forages or to switch to alternative feed sources. Both can affect animal nutrition and increase the risk for intoxications. Use of poor quality forages can cause or exacerbate deficiencies of important minerals such as selenium, copper, and phosphorus and vitamins such as vitamins A and E. In addition, drought affected forages are often deficient in energy and protein. Even in non-drought years, deficiencies in selenium and copper are common in California cattle, particularly beef cattle. Copper deficiency causes reduced production, diarrhea, decreased resistance to infectious agents and parasites, poor vaccine response, loss of bone strength in calves, weakness and wobbling in neonates, reproductive failure, and sudden death of adult animals. Selenium deficiency also results in less resistance to infectious agents and parasites, and causes white muscle disease of skeletal and heart muscle resulting in stiff gaits, slow movement, heart damage and weak neonates. Primary vitamin A deficiency occurs in beef cattle on dry range pasture during periods of drought. Clinical signs include night blindness, dry eye, retarded growth rate, reproductive failures, and increased mortality. Maternal deficiency of vitamin A can cause abortions, stillbirths, or calves born alive but blind and weak that die within 1 to 3 days. Cows should be given an injection of vitamin A (and D) about 30 days prior to calving and calves should be given a vitamin A injection at birth.
Increased incidence of plant poisonings — Cattle will seek out and consume plants that they would not otherwise find palatable during drought conditions. Nitrate poisoning is one of the most common plant associated intoxications diagnosed by the California Animal Health and Food Safety Laboratory. The potential for nitrate poisoning to occur is increased when livestock water sources also contain elevated concentrations. The first sign of nitrate poisoning is often the sudden and unexplained deaths of one or more animals. Other clinical signs include drowsiness, weakness, muscle tremors, increased heart and respiratory rates, staggering, and recumbency. Signs can develop with several hours of ingesting a toxic amount. Nitrate concentrations can be easily and cheaply determined from samples submitted to a veterinary diagnostic laboratory for testing.
During periods of drought, cattle producers should be especially careful about the quality of feed and water available for their animals. Sick animals should be tested for various nutritional deficiencies and dead animals can undergo necropsies to determine cause of death so that other animals in the herd can be treated appropriately. Additional information and testing is available at the California Animal Health and Food Safety Laboratory System. For laboratory location and contact info, visit www.cahfs.ucdavis.edu. A longer, more detailed version of these tips may be found here.
Robert H. Poppenga and Birgit Puschner, veterinary toxicologists with the California Animal Health and Food Safety Laboratory System at UC Davis School of Veterinary Medicine, contributed to this article.