Posts Tagged: avian

Bird owners urged to take precautions for avian flu

En español

The highly contagious avian flu is being spread primarily by migratory birds, putting game birds, and backyard and commercial poultry at risk.

“Poultry owners should take precautions to prevent their birds from contacting waterfowl or the habitat that waterfowl frequent because this strain of avian influenza is highly contagious,” said Maurice Pitesky, UC Davis School of Veterinary Medicine associate professor of Cooperative Extension.

Infected waterfowl shed the highly pathogenic avian influenza virus in their feces and respiratory secretions, where the virus can remain viable for months in the environment.

“If you can't confine your birds in a coop, focus on good sanitation and reducing contact with waterfowl and their habitat such as agricultural fields and ponds,” he said.

Pitesky urges commercial and backyard chicken owners to monitor their birds for the following symptoms: 

• Reduced egg production
• Trouble breathing
• Clear, runny discharge from nose, mouth and eyes
• Lethargy or lack of energy
• Loss of appetite
• Drinking less
• Swollen eyes, head, wattles or combs
• Discolored or bruised comb, wattles or legs
• Sudden death

To prevent exposure to potentially infected waterfowl, Pitesky suggests reassessing and redoubling biosecurity efforts to prevent contact between wild animals and domestic poultry.

Specifically, he recommends keeping birds away from ponds and other open water where they may contact waterfowl, which are the primary reservoir of the disease. To prevent cross-contamination, use clothing and boots that stay on your property and avoid sharing equipment with other bird owners.

A local veterinarian or UC Cooperative Extension farm advisor may have more suggestions to reduce risk. 

For more information about protecting birds from avian influenza, visit https://ucanr.edu/sites/poultry/files/225352.pdf.

Unusual or suspicious sick or dead domestic birds should be reported to the California Department of Food and Agriculture Sick Bird Hotline at (866) 922-2473.

Suspicious wild bird deaths can be reported to California Department of Fish and Wildlife (CDFW) at https://wildlife.ca.gov/Conservation/Laboratories/Wildlife-Health/Monitoring/Mortality-Report.

Fall is best time to clean nest boxes for barn owls

Research shows land managers should clean nest boxes in autumn to avoid disturbing the raptors

When it comes to American barn owls, forget spring cleaning.

The best time of year to clean out nest boxes to ready them for breeding pairs is the fall months of September through November, according to research out of the University of California, Davis, that analyzed nearly a century of banding and other records.

In a paper published in the Journal of Wildlife Management, researchers found that the median egg laying date for barn owls (Tyto furcata) in California is Feb. 20, so cleaning nest boxes in the fall is recommended.

“The risk is you could disrupt a nest that has already started,” said lead author Ryan Bourbour, a Ph.D. candidate in ecology in the Department of Animal Science at the time of the study. “We want to reduce disturbances to nesting pairs even in the weeks prior to egg laying.”

American barn owls offer a natural way for land managers and agricultural operations to control pests, because the raptors eat mice, gophers and rats. One breeding pair can consume up to 2,000 rodents annually, according to the UC Davis School of Veterinary Medicine.

But natural tree cavities and old barn structures are not as plentiful as they once were, so installing nest boxes can attract the barn owls. And land managers who spend money installing these “nest box networks” have long asked about the best time of year to do maintenance and cleaning. Planning cleaning and maintenance well before the start of the breeding season is “part of making that nest box worthwhile,” Bourbour said.

Pellets add up

After eggs hatch, nestlings spend their early days eating and living in the nest boxes until they are able to leave the nest, said Breanna Martinico, another paper author and an animal science Ph.D. candidate in ecology.

The nestling period of roughly 65 days is considered long.

“That's two months where owls are living and growing exclusively in that nest box,” said Martinico, who is also a UC Cooperative Extension human-wildlife interactions advisor in Napa, Lake and Solano counties.

As many as five or six nestlings are typically in a box, and they eat up to four or five rodents each day. Nestlings swallow their prey whole, and what isn't digested — fur and bones — is coughed up in round or oval-like pellets.

“They're in there for seven to eight weeks just regurgitating these pellets,” Bourbour said. “A lot of pellets pile up over the course of a breeding season and a lot of these boxes need to be cleaned out.”

From anecdotal to data

Discussions about how early the breeding season starts have mostly been anecdotal. To get a better picture, the paper's authors analyzed 96 years of banding records from the United States Geological Survey Bird Banding Lab and 39 years of intake records from California Raptor Center at UC Davis. Both databases helped them estimate the typical egg laying time of year in California, Martinico said.

Having this information can help land managers ensure maintenance is done and nest boxes are safe for the next breeding pair, helping barn owl populations while also benefiting agricultural operations.

“We can give them tools to manage barn owl nest box networks effectively and maximize pest control through owls,” Martinico said.

Additional co-authors include Emily Phillips, Jessica Schlarbaum and Joshua Hull in the Department of Animal Science, Michelle Hawkins in the Department of Medicine and Epidemiology at the UC Davis School of Veterinary Medicine and Sara Kross from Columbia University.

Funding came from the National Institute of Food and Agriculture's Western Sustainable Agriculture Research and Education program.

The journal article is entitled Banding records of nestling barn owls reveal optimal timing for nest box maintenance in California.

Poultry owners urged to protect birds from avian influenza virus

A strain of highly pathogenic avian influenza is currently infecting and killing wild birds and domestic birds in at least 29 states across the United States.

A UC Agriculture and Natural Resources poultry expert urges commercial and backyard chicken owners to take precautions.

“When it comes to protecting your flock, there is no treatment for HPAI so the best thing you can do is focus on biosecurity,” said Maurice Pitesky, UC Cooperative Extension poultry specialist in the School of Veterinary Medicine at UC Davis. 

“In order to protect our commercial and backyard chickens, it is essential for all of us who own poultry to do our part,” he said.

The current avian influenza outbreak is already considered the worst bird flu outbreak since the 2015 HPAI outbreak when nearly 50 million poultry were euthanized or died.

The HPAI virus is being spread by migrating birds and California is part of the Pacific migratory flyway.

“Waterfowl migrate thousands of miles between wintering and breeding locations and have long been known to be the natural reservoirs for avian influenza viruses, which are associated with high mortality in poultry,” Pitesky explained. “Many of these migrating ducks, geese and swans winter in the relatively warmer climate of California's Central Valley among other locations where they can find appropriate habitat.” 

Pitesky recommends preventing chickens and other poultry from exposure to waterfowl and other potential wild bird carriers.

“At the most generic level, that means making sure your birds are separated from any wildlife,” he said. “Whether you have a million-bird farm or just a few backyard chickens, the message is the same: maintain the best biosecurity you can, which includes fencing and make sure you reduce reasons for waterfowl to come near your birds such as spilled feed and ponding of water.

“Our previous research has shown that waterfowl are attracted to both natural and human-made wetlands and lagoons. So, if you live near one of these types of habitats, your biosecurity efforts are even more important.” 

The HPAI virus does not currently affect humans. Pitesky said it is important to recognize that avian influenza viruses, like all viruses, can mutate or recombine to form new versions of virus that may affect humans.

For more information on biosecurity and where HPAI has been identified in the U.S., please visit the UC Cooperative Extension poultry website at https://ucanr.edu/sites/poultry/Resources_335/HPAI.

Poultry owners who have questions may reach Pitesky at mepitesky@ucdavis.edu.

New California Waterfowl Tracker website launched to help poultry producers assess bird flu risk

To reduce potential exposure to avian influenza, a new interactive website is now available to help California poultry producers, backyard poultry enthusiasts, regulators and risk managers assess the locations of waterfowl relative to poultry farms in the Central Valley.

While not all waterfowl carry avian influenza, the migratory birds are the primary reservoir of the virus that kills chickens, turkeys and other birds and can take an economic toll on the poultry industry. During an outbreak of a highly pathogenic strain of avian influenza in 2014-15, nearly 50 million birds had to be killed to contain the disease in the United States.

“Avian influenza is such a devastating disease, in an abundance of caution, we want to limit any interaction between waterfowl and domestic poultry,” said Maurice Pitesky, UC Cooperative Extension poultry specialist.

The California Waterfowl Tracker has been developed by Pitesky at the School of Veterinary Medicine at UC Davis, the University of Delaware, U.S. Geological Survey and UC Agriculture and Natural Resources to show where waterfowl are.

From September through March, geese, ducks and other waterfowl migrate by the millions via the Pacific Flyway and winter in California wetlands, rice and corn fields. At the height of migration, the Central Valley is home to 3 million waterfowl.

The Central Valley is also home to the majority of the state's commercial egg-laying hens, broiler chickens and turkey flocks.

Using the web app to understand when and where waterfowl are feeding and roosting, poultry farm managers and other stakeholders will be able to consider waterfowl in their decision making. They may decide to place pasture-raised poultry in a region of the state that has less wetlands, such as Fresno. If a large number of Canada geese take up residence nearby, poultry owners may decide to move their domestic birds indoors to reduce their exposure until the migrating waterfowl move on.

Using a machine-learning approach developed by Jeff Buler, University of Delaware wildlife ecology professor, the web app produces a waterfowl density map of California's Central Valley that is automatically updated daily with both satellite and weather station information.

“The model doesn't tell us whether waterfowl are carrying avian influenza, but it helps poultry producers and regulators understand where those interfaces could happen,” Pitesky said.

Additional waterfowl habitat and next-generation radar analysis of waterfowl are integrated into the web app. Users can search one or more addresses to anticipate their farms' interaction with waterfowl. Based on the proximity of waterfowl and wild bird monitoring information from the U.S. Fish and Wildlife Service, poultry owners can make biosecurity decisions.

“While the current version of the website is designed for California, the long-term goal is to develop and expand this system for the continental U.S. to promote health and safety of poultry flocks nationally,” Pitesky said.

To use the California Waterfowl Tracker, visit the UC Cooperative Extension Poultry website http://ucanr.edu/sites/poultry. A video of Pitesky demonstrating how to use the web app can be viewed at https://youtu.be/EOO0Q_ggZ9I.

Poultry producers who would like to be notified by UC Cooperative Extension if there is an avian influenza outbreak in their area can sign up on the California Poultry Census page at http://ucanr.edu/sites/poultry/California_Poultry_Census.

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