ANR Green Blog
The same weather radar technology used to predict rain is now giving UC researchers the ability to track wild birds that could carry the avian influenza virus. Avian influenza, which kills chickens, turkeys and other birds, can take a significant economic toll on the poultry industry. In 2014- 2015, the United States experienced its worst bird flu outbreak in history, resulting in more than 48 million birds dying in 15 states, including California.
“We use the existing network of weather radar stations in the U.S. in the same way that radar is used to track rain, except that we process the data to allow us to interpret the radar signal bouncing off birds instead of raindrops,” said Maurice Pitesky, UC Cooperative Extension poultry specialist. “The data can be interpreted to track birds.”
“By tracking mass bird movements remotely in real-time, we hope to gain novel strategic insights with respect to surveillance and prevention of avian influenza transmission to domestic poultry,” said Todd Kelman, a veterinarian and engineer who co-leads the project with Pitesky, who is also in the School of Veterinary Medicine at UC Davis. They are exploring how the information might be used to prevent an outbreak.
In California, waterfowl migrate by the millions from September through March via the Pacific Flyway, where they winter in wetlands, rice and corn fields. The Central Valley alone is home to 3 million waterfowl at the height of migration.
“Using NEXRAD and various other approaches, we hope to be able to produce monthly or quarterly maps that will alert poultry producers as to the locations of waterfowl in the Central Valley of California,” Pitesky said.
“Waterfowl populations can have different habitat based on the amount of precipitation in a given year,” said Pitesky. “Therefore, we need to use these types of monitoring tools to understand where waterfowl are located. Landsat, or satellite-based land imagery, and NEXRAD are two remote tools that may be very useful, as opposed to flyovers and banding, which are more expensive and not practical for large geographical areas.”
The project — funded by UC Agriculture and Natural Resources — is a collaboration between UC Davis School of Veterinary Medicine and Jeff Buler, University of Delaware wildlife ecologist whose team first developed the NEXRAD approach in the Central Valley of California. They are also working with the U.S. Geological Survey, the California Department of Food and Agriculture, the California Poultry Federation, the Pacific Egg and Poultry Association and Point Blue, an organization that focuses on conservation science.
Most Americans envision healthy mustangs galloping free on the range when they think about the country's wild horse population. But UC Cooperative Extension rangeland advisor Laura Snell sees another image.
In conducting research on the over-populated wild horse territory at Devil's Garden Plateau in Modoc County, she witnesses a group of horses visiting a dwindling and damaged pond.
“Maybe there is enough for the lead stallion and the lead mare to drink. The rest stand there and look longingly at the diminished water source,” Snell said. “They do not seem content.”
The research Snell has underway at Devil's Garden was chronicled in the current issue of California Agriculture journal by executive editor Jim Downing. The federal government has determined the ideal horse population on the 230,000 acres of wild horse territory is no more than 402, however, more than 2,000 wild horses are running on the land.
Snell began working in the remote northeast corner of California in 2015.
“I had Modoc County ranchers coming up to me on my second day of work asking me how to solve the wild horse issue,” she said.
She realized that agencies and authorities responsible for policies that determine the horses' fate, and advocates who lobby strongly that the horses should be cared for humanely, don't see the poor conditions suffered by the horses and the environmental degradation of the land.
“The area is a quarter million acres in size. There are no main roads, so you have to take ATVs to see the horses,” Snell said. “We realized we needed to provide visuals to show people the horses and what the landscape looks like due to unmanaged grazing by the wild horses.”
Snell places wildlife cameras for two-week periods near 24 remote water sources in wild horse territory in Modoc and Lassen counties. At each site, the camera takes a burst of three pictures automatically every 15 minutes; motion detectors on the cameras also trigger a shot whenever an animal enters the field of view.
Preliminary data from 2015 show some striking findings. At one spring site, for instance, more than 71 percent of all animals detected over the sampling period were horses. Cattle accounted for 19 percent and the rest were pronghorn antelope, deer and hawks. The study will continue through 2017.
Wild horses are running in the Devil's Garden territory, and outside the territory, on private and tribal land. Fences don't hold the horses in, Snell said. Federal wild horse management areas are intended for multiple uses, including livestock grazing, hunting, and wildlife habitat. But in Devil's Garden, livestock have been excluded because of the environmental degradation.
“It was never intended to be single use area,” Snell said. “The horses are gorgeous animals, but I also like to see pronghorn, elk and mule deer. Some groups of wild horses are getting large and studs are getting aggressive. I know people who no longer ride their personal horses because it's not really safe with the territorial nature of the stallions.”
The images and data from Snell's research are designed to inform management and policy decisions in hopes of easing the expensive and environmentally harmful wild horse over-population. Already U.S. Representative Doug LaMalfa (R-Oroville) has brought the study to the House Committee on Natural Resources and preliminary results have been shared with Bureau of Land Management's Wild Horse and Burro Advisory Board.
Representatives from the date and ornamental palm industries, arborists and pest managers, parks and recreation officials, and home owners are uniting behind a University of California, Riverside initiative to slow the spread of the South American palm weevil, a palm tree-killing insect that has established in San Diego County.
“Everyone recognizes the threat and agrees it is significant,” said Mark Hoddle, UC Cooperative Extension specialist in biological control based at UC Riverside.
However, Hoddle said, action is hampered significantly by a lack of financial support at the state and federal level for research to answer questions about the distribution of the weevil in Southern California, how far it can fly from infestation zones, control options, and the most efficient and sensitive ways to monitor and trap it.
Hoddle recently helped organize a symposium just outside San Diego on the South American palm weevil. Recent detection in California of the weevil, which has traditionally been found in South and Central America, the Caribbean and Mexico, has scientists, farmers and nursery industry officials worried because it threatens California's $70 million ornamental palm industry and $68 million commercial date industry.
“My personal feeling is we might be on the verge of a crisis now,” Hoddle said. “The big problem is we don't know how far the weevil has spread. We really need help from the public in tracking its spread.”
The South American palm weevil (Rhynchophorus palmarum) is not to be confused with the palm weevil Rhynchophorus vulneratus, which originated from Indonesia and was incorrectly identified as the red palm weevil, Rhynchophorus ferrugineus, when it was found killing palm trees in Laguna Beach in 2010. R. vulneratus was declared eradicated from California on Jan. 20, 2015.
Feeding by larvae of the South American palm weevil damage the growing area of the crown of palm trees. The tree is then unable to produce new fronds, and within months it dies. Canary Islands date palms are particularly vulnerable and it is likely date palms will be attacked too. California also has a native palm species (Washingtonia filifera), which grows in desert oases and may be vulnerable to attack.
Detection of the South American palm weevil was officially confirmed May 9, 2011. Seven additional detections were made in July and August 2011. These initial detections by the USDA were in San Ysidro in San Diego County, about two miles from the Mexican border. It is likely that the weevils flew from Tijuana, Mexico, where infestations and dead palms had been detected in December 2010.
As a result of those detections, weevil traps were set up throughout California, Arizona and Texas with financial support from the USDA. A total of 111 South American palm weevils were captured in California; 109 in San Diego County and two in Imperial County. They were also found in Alamo, Texas, and Yuma, Ariz.
The traps were monitored from 2011 to 2013. Then, monitoring stopped when federal funding for the program expired.
Since monitoring stopped, it appears the problem has worsened, said Hoddle, who is also director of UC Riverside's Center for Invasive Species Research. In May 2016 he did a casual eight-hour driving survey in Tijuana, Mexico and found about 125 dead Canary Islands date palms that had been killed by the South American palm weevil.
In August, 2016, Hoddle placed 10 weevil traps at Sweetwater Regional County Park, about 15 miles east of San Diego. Since then, he has been catching about five to seven weevils per trap per month. In the coming months, he plans to start monitoring the heath of the palm trees in Sweetwater Regional Park using a drone.
Hoddle considers the South American palm weevil situation more dire than what he encountered with Rhynchophorus vulneratus because he fears the South American palm weevil has spread further and it spreads the red ring nematode (Bursaphelenchus cocophilus), which also kills palm trees.
Red ring nematodes, which have not yet been detected in California, can enter palm trees through the damage South American palm weevils do to the trees. The nematodes can also enter the bodies of the weevils when they are larvae. Then, the larvae turn into adult weevils which are strong flyers and they can then spread the nematode to other palms when the feed or lay eggs on them.
California is in the middle of the Pacific Flyway, a major north-south flyway for migratory birds, and also bats, that extends from Alaska to South America.
“Every autumn, migratory bats, such as the Mexican free-tailed bats, travel to their overwintering grounds in Southern California and Mexico, where there's plenty of bugs to eat; they come back each spring to raise their families,” said Rachael Long, a UC Cooperative Extension advisor who studies bats.
Bats are beneficial because they feed on insects, including mosquitoes and pests such as codling moths that damage fruit and nut crops. The economic value of bats for pest control on farms has been estimated by some studies to exceed $23 billion per year. Long, who serves Sacramento, Solano and Yolo counties, is studying the value of bats for pest control in walnut orchards.
In the city of Davis, officials recently warned people to stay away from bats after bats found on the UC Davis campus tested positive for rabies. Long agrees with the warning, but worries that it might also result in healthy bats being killed.
“This is most unfortunate for people and bats, but not a surprise at this time of year. Right now, thousands of bats are flying through our great Central Valley, migrating south for the winter, just like ducks and geese, so there's a higher chance of contact,” she said “We just don't see bats as much because they are flying at night, using the stars, earth's magnetic field, and landscapes to navigate.”
Their journey south is lengthy, from as far north as Washington state to Mexico, and exhausting, so bats need to rest along the way.
“Sometimes you'll see one or more tucked up in the corner of your house, such as under an eave,” Long said. “If so, use this as an opportunity to share with others the amazing life of a bat that can fly over a thousand miles to their overwintering grounds and back again in the spring. Leave them alone, let them rest, and they will fly away after they've rested and recovered.”
If you have to move a bat, she notes you should wear gloves and not handle a bat with bare hands because they will bite in self-defense.
“If you find a bat on the ground, place a box over the bat and using a piece of card, slip it under, then gently and carefully slide the bat into the box,” Long said. “Place the box at 4 to 5 feet off the ground and open it (bats usually can't take off from the ground). The bat can then crawl out of the box in its own time and fly away.”
“If the bat does not fly away within 30 minutes, it is probably sick or injured. In this case, contact a wildlife rescue unit in your area.”
Long noted that animal control officers have to euthanize bats to test for rabies.
“The bat may be perfectly healthy, just tired,” she said. “If no people or pets have obviously touched the bat, you can call a wildlife rescue organization. If in doubt, call animal control.”
If a bat does have rabies, Long said, “Rabies dies within five to 10 minutes after the bat dies.”
For more information on the benefits of bats, see Long's post in UC ANR's Green Blog, “Bats in the Belfry? No, Bats in Walnut Orchards” at http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=17395.
How do you cut your water use by a third, cut your nitrogen use in half, maintain your tomato yield and improve your fruit quality?
“With patience, perseverance and by treating your soil like a living ecosystem — which it is,” says Jesse Sanchez.
Sanchez should know. He and Alan Sano have been experimenting with soil enhancements for 15 years on Sano Farms in Firebaugh. They believe they have hit upon a winning strategy — though their experiments continue.
Today, they grow 50-ton-per-acre tomatoes with half of the nitrogen (120 units) and a third less water than before. They also report fewer weeds and better tomato quality.
The soil organic matter (SOM) — the living portion of the soil that turns crop residue into minerals needed by growing plants — has gone from 0.5 percent to 3.0 percent, report Sano and Sanchez.
“The soil is like day and night,” says Sanchez. “You can dig it with your hands,” he says, cupping a handful to prove his point.
So how do you transition largely inert soil into the ecological powerhouse found on Sano Farms?
Cover crops, reduced equipment passes, and subsurface irrigation have been key, according to Jeff Mitchell, UC Cooperative Extension specialist based at the UC Kearney Agricultural Research and Extension Center. These practices combine to feed and protect the soil microorganisms often ignored in agricultural systems. Mitchell has been coaching the Sano/Sanchez team for over 10 years, witnessing their progress and connecting them with like-minded farmers and organizations.
“Farmers sometimes worry that cover crops will compete with the cash crop for water and nutrients,” says Mitchell. “We're starting to see at Sano Farms — looking long term — that the tradeoffs might actually be favorable.”
Sanchez says he terminates the cover crop before the tomatoes are planted, leaving the dead residue to smother weeds and feed the soil microorganisms.
The SOM also builds the sponge that allows the farm to thrive on less water, says Zahangir Kabir, soil health specialist with USDA's Natural Resources Conservation Service.
“A one percent increase in SOM builds your soil's ability to hold water by 19,000 to 25,000 gallons per acre. Calculating conservatively, Sano Farms' fields hold 50,000 gallons of water more per acre than they did before," Kabir said.
You can see this in action at Sano farms. “When it rains here the water soaks into the field. It stays put,” says Sanchez. “It doesn't run off like some farms.”
Sanchez, who received a White House Champions of Change Award last summer, says he knows farmers resist change. “But we can't stop change,” he says. “It's all around us.”
And, if they (farmers) do change the way they work with their soil, says Sanchez, “they are going to like what they see. ”
Sanchez will be a featured speaker at the second annual Latino Farmers Conference on Nov. 15 at the Monterey Hyatt Regency. The event is free but registration is required. http://www.nrcs.usda.gov/wps/portal/nrcs/events/ca/newsroom/events/?eventid=584#584 .
USDA NRCS produced a three-minute video profile of Alan Sano and Jesse Sanchez at Sano Farms in Firebaugh. View it here: