The risk of avian influenza remains a concern for poultry owners in California, according to Maurice Pitesky, a poultry specialist with the University of California Cooperative Extension and a member of the UC Davis School of Veterinary Medicine. Recent cases of highly pathogenic avian influenza (HPAI) have been reported in Sutter and Sonoma counties, prompting animal health emergency teams to work with affected flock owners to contain the virus.
“The risk of diseases is dynamic and is influenced by climate, wildlife movement, and human activity,” said Pitesky.
Temperature changes across different regions in California can lead to the migration of wild waterfowl carrying HPAI into warmer areas. Migratory birds may introduce the virus before moving on, but resident birds can continue spreading it as the virus persists in water, air, and soil. Many poultry farms and backyard flocks are located near bodies of water used by migratory birds. Even if no aquatic birds are seen nearby, the virus can remain present in the environment.
“Climatic factors such as precipitation, soil moisture, temperature, and crop development influence the behavior of waterfowl,” explained Pitesky. “It is a constantly changing situation.”
Outbreaks often occur three to ten days after an increase in waterfowl presence within about 2.5 miles of affected farms. For this reason, Pitesky recommends that poultry keepers assess risks beyond their immediate property.
“When we think about protecting our backyard flocks, we usually focus only on coop biosecurity,” said Pitesky. “But with diseases like highly pathogenic avian influenza—mainly carried by wildlife—it is also essential to understand potential habitats in nearby neighborhoods.”
For example, ponds several blocks away may attract migrating ducks and geese searching for food in residential gardens or golf courses.
Pitesky suggests several basic biosecurity measures: establish solid physical barriers between birds and the outdoors; use fully enclosed coops with solid roofs; cover outdoor areas with mesh or roofing; reinforce openings with wire mesh to exclude small birds and rodents; prevent access to open water sources like puddles or ponds; provide only municipal or well water; elevate feeders and drinkers; store feed in sealed containers; clean up spills promptly; regularly disinfect footwear, tools, and equipment; limit visitor access; quarantine new birds for two to four weeks before integrating them into existing flocks; isolate sick or dead birds immediately and consult veterinary services.
Risk assessment should also include analysis of nearby habitats that attract aquatic birds—such as wetlands, lakes, ponds, drainage canals or irrigated fields—as disease transmission can occur indirectly through contaminated soil, water or air rather than direct bird-to-bird contact. Wild ducks and geese serve as “bridges” for viral transmission while small birds may act as mechanical vectors without showing symptoms. Human activities like visiting parks or wetlands before tending poultry can also raise risks if hygiene measures are not followed.
Pitesky advises thinking in terms of risk levels rather than trying to eliminate all exposure: properties near bodies of water frequented by aquatic birds face higher risk compared to dry environments with little wildlife interaction.
“In the big picture, biosecurity and risk assessment go far beyond just the chicken coop,” said Pitesky. “The goal is to reduce risk—not eliminate it completely.”
Individual actions help protect neighboring flocks as well as commercial operations, livestock, pets and local wildlife since sick birds contribute to regional disease spread.
A mobile application called Backyard Poultry Central provides information resources for backyard chicken keepers—including management tips, outbreak alerts and practical recommendations—and is currently available for Android devices via BYP Central – Play Store.
UC Agriculture and Natural Resources (UC ANR), which supports these outreach efforts statewide by sharing science-based practices https://ucanr.edu/, operates offices in all 58 California counties along with nine Research and Extension Centers serving diverse ecosystems https://ucanr.edu/. The organization applies University of California expertise through research initiatives designed to support communities across California https://ucanr.edu/.