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Weather radar helps researchers track bird flu

This NEXRAD map shows where migrating waterfowl are gathered in rice fields, herbaceous wetlands and other agricultural land.

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.” 

Migrating waterfowl, such as Canada geese and common egret, could carry the avian influenza virus.
NEXRAD, or next-generation radar, is a network of 160 high-resolution S-band Doppler weather radars operated by the National Weather Service. The technology works best for tracking birds in the winter during feeding. When waterfowl leave their roosting locations in concert to feed, their bodies produce reflectivity of the radar beam.

“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. 

This Landsat map shows wetland coverage in the Sacramento Valley in 2007, a rainy year, and 2015, a dry year.

“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.

Posted on Wednesday, December 7, 2016 at 11:37 AM

Wild horse over-population is causing environmental damage

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.

Wild horses are beautiful, but present land management challenges.

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.

Laura Snell, left, and USFS rangeland management specialist Jenny Jayo mount a wildlife monitoring camera at Bottle Springs, a water source in Modoc National Forest. (Photo: Will Sukow)

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.

Wild horse impacts near Bottle Springs in the Modoc National Forest. (Photo: Will Sukow)
Posted on Tuesday, December 6, 2016 at 1:18 PM

Trump presidency and potential impact on food prices

President-elect Donald Trump promised to crackdown on illegal immigration during his campaign. Caitlin Dewey reported in the Washington Post that such a move would result in increased fruit and vegetable prices for Americans.

The Post sought information from the UC Agricultural Issues Center (AIC), a statewide program that is part of UC Agriculture and Natural Resources. UC Cooperative Extension was credited as a source for a chart that accompanied the article that noted the crops most vulnerable to labor-cost change. Asparagus is listed as having the highest proportion of the farms' operating costs dedicated to labor: 82 percent. 

"The plants must be hand cut multiple times per day during their two-month harvest season," the story said. Other crops that have high labor costs are wine grapes, oranges, sweet cherries, and all types of fruit. The article said berries, peppers, onions, watermelons and apples are also typically picked by hand.

A Texas A&M agricultural economist, Luis Ribera, told the reporter he believes U.S. farmers may not be able to produce some fruit and vegetables as a result of Trump's planned deportation of undocumented immigrants.

"We had a farm labor shortage even without Trump. Whatever he does will just compound the problem," Ribera said.

The director of the AIC, agricultural economist Daniel Sumner, doesn't express dire concern about the potential impact of the Trump administration on food prices and agriculture policy.

"I do not see big changes in immigration policy relevant for ag. Except perhaps a guest worker program, which would be positive," Sumner said. "I do not see big deportation of farmworkers coming."

Crops that require hand labor are more vulnerable to price fluctuations when immigration policies change.
Posted on Tuesday, December 6, 2016 at 11:14 AM

Is 'palmageddon' coming to California?

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.

South American palm weevil.

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.

UC Cooperative Extension specialist Mark Hoddle is monitoring palm trees at Sweetwater Regional County Park east of San Diego for South American palm weevil.

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.

Dead palm tree infected by South American palm weevil. (Photo: Mark Hoddle)

Posted on Tuesday, December 6, 2016 at 8:46 AM

UC Cooperative Extension to track wild pig damage

UC Cooperative Extension is asking California farmers and landowners to help track the the state's wild pig population, reported Julia Mitric on Capitol Public Radio News. Signs of the pig's presence are hard to miss, UCCE advisor John Harper told the reporter.

"It looks like you came in with a rototiller and just uprooted everything," he says. "It's like ground squirrel mounds or gopher mounds on steroids because the pigs can go over such a large area."

Wild pigs can cause serious environmental damage. (Photo: Silvia Duckworth, Wikimedia Commons)

California's wild pigs have a variety of origins. Harper says many are descended from domestic pigs who were released into the wild by humans or escaped on their own and bred with game hogs such as the Russian boar hog. Wild pigs root around  in the soil for truffles and small plant roots with their sharp tusks tear, destroying plants and grasses that sheep and cattle like to graze on. They also open up the land for erosion and invasive species.

"So you might get something like 'medusahead,' an invasive grass that tends to crowd out other more desirable forage species," Harper said.

A team of UC Cooperative Extension scientists have created a GIS-based mobile app that works on Android and Apple devices to make it easy for landowners to participate in the study. 

“Rangeland managers and farmers can enter data into the app from the field so that we can estimate the land area and economic impacts of feral pig damage over a longer time period,” said Roger Baldwin, UC Cooperative Extension wildlife specialist in the Department of Wildlife, Fish, and Conservation Biology at UC Davis.

Learn more and sign up to participate in the study on the UC Agriculture and Natural Resources news website.

Posted on Friday, December 2, 2016 at 11:08 AM

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