'Birds Are Confused': Warming Winters Fueling Bird Flu Spread In PA

PENNSYLVANIA — More than 4.4 million birds have been slaughtered due to the highly contagious avian influenza in Pennsylvania. While much of that damage came in 2022, the virus remains very much alive both domestically and abroad.

Some 35,000 birds were killed at a pair of Lancaster County farms in January. Officials issued urgent warnings at the time: "it could devastate an industry," Pennsylvania Emergency Management Agency Director Randy Padfield said.

Three more outbreaks have occurred since then in Pennsylvania, with the most recent occurring on Feb. 8. A total of 56,320 birds have now been killed in the state in 2023 alone, according to the U.S. Department of Agriculture, including one backyard flock and three commercial flocks.

A total of 58.3 million have been killed in the United States since Jan. 1.

In the robust interagency attempt to control the spread of the virus, officials are looking at everything from biosecurity on farms to increasing inspections and improving health standards elsewhere. One thing that's out of their control: climate change.

Climate impacts migration patterns for all species, including birds. This year is the warmest winter on record, and birds that normally would not be moving around this time of year suddenly think it's time to fly north.

"These birds are confused," Pennsylvania Secretary of Agriculture Russell C. Redding told CBS News, citing the higher temperatures this winter. "They're on the move."

Redding added that they're doing what they can to try to anticipate when these moves could impact Pennsylvania. Agriculture officials were on high alert last month after an avian flu outbreak in Virginia, because many birds are on the same migratory flight path that passes over both Virginia and Pennsylvania.

Much of the east coast, including large swaths of Pennsylvania, have never seen a warmer winter, according to records from the National Oceanic and Atmospheric Administration. It's throwing the balance of delicate ecosystems into chaos, creating earlier blooms and causing atypical animal behavior.

"While things are getting warmer, the weather is also getting more erratic. And so, plants and animals are responding to these kinds of chaotic weather patterns all very differently," Megan O'Connell, a research associate with the Botanical Research Institute of Texas, told AccuWeather. "It's not that we're going to see everything just move forward together. It seems like species are all responding differently, which is the reason we're seeing a lot of these kinds of mismatching trends."

And the science says it's about more than just birds confused by temperature and what direction they're supposed to be heading. The changing climate impacts the availability of breeding sites — sites which in many cases are already limited by overdevelopment and other human impacts — which can cause overcrowding and higher than usual interaction between domestic birds and migratory birds. This fuels the spread of the disease, according to recent research published in the Journal of Climate Change and Health.

In addition to America, the United Kingdom, France, and Japan have all suffered heavy losses from bird flu. But like other viruses, it discriminates for no socioeconomic boundary and no political border. A Reuters report Wednesday details the spread of avian influenza to South America, Europe and Asia at large, and Africa.

Eggs and other poultry products out of the state remain safe to eat, the Pennsylvania Department of Agriculture has assured the public. Officials say the chances of infected chicken entering the food chain are "extremely low" because food facilities test for the virus so frequently. Poultry products are further inspected for disease several times on the way from the farm to the store.

The highly contagious and fatal disease hits domestic poultry the hardest. Impacted species include chickens, ducks, geese, turkeys, guinea fowl, quail, pheasants, emus and ostriches. Wild species also can pick up the flu, as the flu was first detected in the state in a wild bald eagle in East Marlborough, Chester County, in March 2022.

Mass euthanasia is the typical first response of state responders. Agriculture officials continue to urge farmers to install enhanced biosecurity measures to protect their flocks.