New Bird Flu Strain Threatens North American Wildlife – Oregon Capital Chronicle

This year’s bird flu epidemic is the first in North America since 2015 and is caused by a version of the virus that virologists and wildlife managers have never seen before. “It’s acting according to a different set of rules,” said Brian Richards, coordinator of emerging diseases at the National Center for Wildlife Health. I’m here.

From droughts to wildfires to habitat loss, wildlife is already facing unprecedented stressors.Currently, the emerging and widespread form of avian influenza is still another new serious threat — We need new approaches to disease control in farms, shelters and landscapes across the country, say wildlife biologists. Rebecca Paulson, a research scientist at the University of Georgia who has studied bird flu for 15 years, said: “We’ve never seen anything like this before.”

Before 1996, Highly pathogenic avian influenza was widely thought to infect only commercial poultry farms. These were pathogenic, but included outbreaks caused by mutations on farms of wild bird-derived influenza viruses. This has made outbreaks easier to manage through biosecurity prevention, isolation of exposed flocks, and rapid culling.

In 1996, virologists first detected the H5N1 strain in domestic geese in Guangdong, China. The virus gained global attention in 1997 when it infected 18 of his people in Hong Kong and killed six. The outbreak sparked international fears of a human pandemic, but the virus never mutated to allow human-to-human transmission. The international media did not pay much attention to the fact that by 2002 he had acquired the ability of H5N1 to return from domestic flocks to wild birds. Since then, viruses have continued to evolve.

Today, several HPAI variants are associated with “sporadic mortality events” in wildlife. Seaside cliffs have emptied in Newfoundland and Labrador in 2021 due to current tensions. Thousands of boobies, puffins and murresThis August it killed 700 Cinereous Vultures in a Georgia sanctuaryWaterfowl, shorebirds, raptors and carrion eaters are most at risk. In the western states recently hit by the virus, such species include endangered birds such as the California condor and the common plover, although the agency has yet to document infections in either species. The common Canadian geese and crows that live in Canada’s urban and suburban areas, as well as the nationally iconic bald eagle, are also at risk, now beginning to peak in the northern provinces and heading south until late October. So are the hundreds of millions of waterfowl that do.

I think we are at the tip of the iceberg. We are just holding our breath to see what happens.

– Rebecca Poulson, University of Georgia Research Scientist

The last outbreak caused by a related strain, H5N8, reached North America in 2014, costing US farmers $3 billion and 50 million chickens, turkeys and waterfowl having to be culled. did not. This year’s epidemic has affected the same number of commercial birds so far, but is orders of magnitude greater in the wild landscape. Wild bird transmission has nearly doubled the number of backyard poultry, with outbreaks in 2014-15 he only being recorded in 18 wild bird species in 16 states, but this year at least 108 wild bird species. confirmed in the species. Almost every state has cases. In another unusual development, a number of mammalian crossover cases and deaths have also been confirmed in foxes, skunks, opossums, raccoons, bobcats, minks, harbor seals, juvenile black bears and a bottlenose dolphin. The institute is so overwhelmed that wildlife officials say they have stopped submitting carcasses of species already recorded in the county. The official number of wild bird deaths is grossly underestimated, as they have only submitted data.

The next few months could be even worse. Flocks across the continent are now migrating toward Central and South America, home to some of the most diverse bird species on the planet. “I think we are at the tip of the iceberg,” Paulson said. “We’re just holding our breath to see what happens.”

In the western states this fall, California is likely to bear the brunt of the impact the most, being one of the largest egg producers in the United States and commercial poultry meat being the state’s sixth largest commodity, worth $1 billion annually. I have. California’s Central Valley is an essential migratory and wintering site for wild birds. The Sacramento National Wildlife Refuge alone is visited by tens of millions of migratory birds each fall. It supports almost 40% of the continent’s pintails (one of the most abundant ducks in the world) and hosts a wintering population of birds totaling about 1.5 million.

This year’s drought has meant that wintering herds are unusually crowded and particularly mobile, potentially increasing the risk of spreading the virus, said the reserve’s chief wildlife biologist. Michael Derrico said. Since shelter wetlands are half their normal size, birds are forced to stay closer and may migrate frequently to find resources, and derico may push birds further south. I believe there is

Once the disease becomes established in a free-range herd, you really don’t have the upper hand.

– Bryan Richards, Emerging Disease Coordinator, National Wildlife Health Center

Derrico’s concerns about birds on the Pacific Flyway are tempered somewhat by the fact that so far the country’s westernmost migratory bird routes don’t appear to have as many viruses as elsewhere. But he and other wildlife managers are also very limited in what they can do to mitigate potential impacts.

From the USGS headquarters near Madison, Wisconsin, Richards said: “We’re really good at documenting disease in the landscape, but we’re not very good at changing the outcome of disease.” We’re starting to pivot towards discussing wildlife health,” he said.

For Derrico of the Sacramento Conservation Area, promoting health instead of preventing disease would require increased investment in wetland management to ensure that birds have access to the largest possible habitat, allowing birds to disperse to new locations. It may be necessary to minimize human interference to prevent In many parts of the country, bald eagles and other birds of prey have died extensively from lead poisoning from bullets and fishing gear.

“It’s something we can control, isn’t it?” he said. By addressing environmental factors within human reach, combined with improved biosecurity measures on farms, wildlife managers can make birds more resilient in the face of deadly new diseases. Richards believes it might be possible.

The pressure to change wildlife disease management is only increasing. “When you look at emerging infectious diseases globally, we see some very interesting trends,” said Richards. “We’ve seen more new diseases, bigger disease outbreaks, more frequent and bigger impacts.” These include those that can mutate and become widely contagious and transmissible to humans, as seen with COVID-19. Virologists believe the risk of that happening with this H5N1 strain is low, but they recommend that hunters, farm workers, and other bird handlers take extra precautions this year anyway. Wildlife is responsible for most of the new diseases that threaten people, according to Richards.

This story was originally published by high country news.