Reports of avian flu cases rising throughout Long Island, New York State

The discovery this week of dozens of dead waterfowl near Patchogue, likely killed by bird flu, came amid what a Cornell University scientist said was an uptick in reports statewide.

"There have been quite a few cases, sometimes 50 or so reports a day" statewide through an electronic reporting form for avian influenza maintained by state environmental officials, said Krysten Schuler, a wildlife disease ecologist and director of the Cornell Wildlife Health Lab.

Since late January, Schuler said, that form has recorded 176 reports of suspected cases in Suffolk County, 38 in Nassau and 42 in New York City. Not all reports get tested or result in confirmed cases of bird flu. In Suffolk, of 55 birds that were tested, 27 were positive, 12 were negative and 16 were still pending, she said.

Outbreaks of animal disease are not new, but scientists are closely watching H5N1, the current strain of the virus known as bird flu or highly pathogenic avian influenza, because of the scale of its spread and because it has jumped species, infecting not just birds but mammals including cattle and people. Because viruses mutate as they spread, each infection is a chance to evolve into a more contagious and virulent strain.

Schuler said it was too soon to draw many conclusions about the uptick in reported cases in New York, which could indicate virus spread or simply greater public attention to the global spread of bird flu. Cases generally increase in colder weather and subside during the summer.

"This [strain] is definitely different because of the widespread nature," Schuler said. "Wildlife can be an important signal with what’s going on with the health of the environment."

Bird flu was detected in North American wild birds in December 2021 for the first time since 2015, according to the National Wildlife Health Center. It has now been detected in hundreds of bird species and wild mammals, with confirmed cases across most of New York State and much of the country.

In New York, according to the Cornell Wildlife Health Lab, cases have been confirmed in red foxes, a striped skunk, a Virginia opossum, a raccoon and a bobcat. The state also recently had the first confirmed positive case of the virus in an Eastern gray squirrel.

The virus has also spread to commercially raised cattle and poultry flocks, and to a lesser extent to pets and people. The human cases appear to be rare — about 70 nationally — usually mild, and confined to people who work closely with animals, though at least one person has died. Authorities have responded to poultry outbreaks by ordering "depopulation." An outbreak at Crescent Duck Farm in Aquebogue last month resulted in its entire flock of 99,000 ducks being euthanized.

Scientists track cases in waterfowl, raptors and some other birds particularly closely because their vulnerability to the flu makes them known disease vectors and testing helps track the spread of the virus.

Raptors and carnivorous mammals may get infected from consuming sick prey, while waterfowl that congregate in large flocks in the winter will become exposed from other birds or ingestion of virus shed in water, according to the Cornell College of Veterinary Medicine. Symptoms of the virus in wild birds include eye swelling, tremors and seizures.

Since late Wednesday, when New York State Department of Environmental Conservation officials said bird flu was the likely cause of death for about 20 ducks, geese and shorebirds found Tuesday on an East Patchogue beach, several South Shore residents have told Newsday of bird carcass sightings in locations from Patchogue to Smith Point County Park, a span of about eight miles.

In Patchogue, Ron Thelian, 65, who runs a senior home care agency, said he saw several dead birds last week and through the weekend. Monday it was half a dozen. Tuesday it was 30 or 40. He buried them deep in the sand to keep the seagulls and raccoons from finding them and getting infected too.

Thelian said it was a common if disturbing sight to see jetsam float off the Great South Bay. "But did we ever see something like this? This was terrible."

DEC spokeswoman Lori Severino said in an email that prevailing winds over the last few weeks had likely blown shorebird carcasses onto the South Shore beaches, but that cases were distributed throughout the entire region.

Members of the public who see groups of dead birds should treat them as positive for the virus, avoid contact and report the finding to state environmental authorities. In many cases, the birds can be left in the landscape.

Experts said the virus’ ability to jump species, what virologists refer to as a spillover event, was worrying. "Every time it gets into a mammal, it potentially could mutate into a form that would be more virulent and spread easily between people" in a manner similar to COVID-19, said Kevin Hynes, a DEC biologist, in a recent video presentation. "That would be a serious problem if it was a version of the virus that had a high mortality rate."

Hynes said that there were no documented die-offs of songbirds and that the DEC did not recommend removing backyard bird feeders, except for people who also keep poultry.

Officers of some of Long Island’s Audubon Society chapters said they had not yet seen extensive population level impact from the flu.

“We’re concerned but we’re not seeing mass mortalities on everybody’s lawn,” said Byron Young, a former DEC marine biologist who is president of the Eastern Long Island Audubon Society.