By Juliet Grable
Avian Flu Update
One year ago, Pepper Trail provided an excellent summary on the status of Highly Pathogenic Avian Influenza, aka HPAI, aka avian flu. At the time, it was evident that the newest subtype of the virus, called H5N1, was infect-ing and killing wild birds on a scale not seen before.
In that same column, Pepper celebrated the introduction of endangered California Condors in Northern California. These eight young birds, which were released by biologists from the Yurok Tribe and Redwood National and State Parks, marked the first time that condors have soared over redwood country in 100 years.
At the time, Pepper warned that it is conceivable that avian flu could affect California Condors, which fly free in established flocks in Arizona-Utah; Baja, Mexico; Southern California; and Central California. Sadly, that has come to pass. Field crews noticed a sick condor in northern Arizona in late March; since then, 20 of the endan-gered birds have died, all in Arizona. Thanks to the vigilance of the folks at The Peregrine Fund, which manages the Arizona-Utah flock, they were able to recover eight live birds and most of the dead birds, thereby preventing them from becoming vectors for additional disease. US Fish & Wildlife Service has established an Incident Com-mand Team to respond to the crisis; you can look for updates on this webpage.
So far, no California Condors in other locations have been infected, and managers of those flocks are watching the birds closely for the first signs of illness. Quarantine pens are in the works for the Central and Northern Califor-nia flocks, so that sick birds can be isolated, tested, and treated as soon as they are detected.
The Peregrine Fund has set up an emergency fundraising campaign. If you’d like to help, please visit: https://www.peregrinefund.org/condor-crisis.
If you’d like to contribute to the quarantine pens in Northern California, please visit: https://www.yuroktribe.org/condor-conservation-donor-information.
Why this outbreak is different
Meanwhile, a group of researchers (Harvey et al. 2023) has published an analysis of the H5N1 outbreak in North America. By synthesizing data from publicly available sources in Canada, the US and Mexico, the researchers have been able to sketch out the breadth and depth of the outbreak.
H5N1 was first detected in North America in Newfoundland in late 2021—first in poultry, then in seabirds. Follow-ing is a summary of how the virus has spread since then. [Note: In all of the quoted material that follows, I have removed the in-text citations to make for easier reading]:
“As of March 2023, there have been ~33,504 suspected or confirmed detections of H5N1 in the United States and ~1721 suspected or confirmed detections in Canada across 141 wild bird species. Over 58 million domestic poultry have been infected or culled in the United States and over 7 million in Canada. In late 2022, H5N1 began spreading into Mexico, Central, and South America, including 22,000 estimated seabird mortalities off of the coast of Peru.”
You can track cases of HPAI through the USDA APHIS website: https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/avian/avian-influenza/hpai-2022/2022-hpai-wild-birds
H5N1 has struck birds in Oregon. To filter for those cases, type Oregon in the search box above the spreadsheet in the link above.
The researchers make several notable observations about why this outbreak is so potentially devastating. First, H5N1 is affecting more species of wild birds than ever before. Because the virus is persisting rather than “fizzling out,” migratory species are continuing to carry the virus to new locations. Colony-nesting birds are especially vulnerable, as are waterfowl, shorebirds, and raptors. So far, songbirds have been largely spared.
The outbreak comes at a time when wild birds are already facing serious declines. Again from the North Ameri-can H5N1 outbreak research study:
“For example, Caspian Terns (Hydroprogne caspia) have nesting colonies in the Great Lake region of North America and are listed as endangered in Wisconsin and threatened in all other Great Lakes US states. It is estimated that 62% of the Caspian Tern population in Lake Michigan died of HPAIV in the summer of 2022. Addition-ally, the Canadian media reported thousands of Northern Gannets (Morus bassanus), along with Common Murres (Uria aalgae), Razorbills (Alca torda), and Great Black-backed Gulls have been reported washing up on coastlines in the Gulf of St. Lawrence region of Canada. This region is home to the largest breeding colony of Northern Gan-nets in North America; this species has historically faced repeated anthropogenic impacts, like DDT contamination, bycatch, and the Deepwater Horizon oil spill. Additionally, some scavenging species have been severely impacted, such as the high nest failure and adult mortalities seen in North American Bald Eagles. Overall, numerous potentially susceptible species have been identified that may be a starting point for vulnerability and prioritization assessments.”
HPAI is likely to become endemic, and we are likely facing more losses from H5N1 in the coming year. On the (slightly) positive side, wild birds that survived exposure likely have some immunity to the variants currently circulating.
Given that HPAI is not going away anytime soon, the researchers are urging a coordinated response among all stakeholders, including the poultry industry and wildlife managers at all levels:
“Our synthesis supports North America facing a future with increased probability of recurrent HPAIV epizootics affecting wildlife, captive species, and poultry, and the potential for continued major economic damage and impacts on food security. Wildlife agencies, industry managers, and public health officials need to make informed, timely decisions in the face of uncertainty, including addressing species of conservation concern, sensitive management areas, and high poultry production areas. A structured decision analysis framework for response to HPAIV mitigation and management across scales would provide tools to identify actions which will best reduce the glaring uncertainties of the HPAIV disease system.”
I realize this is not the cheeriest column, so I’d like to offer at least a glimmer of positive news. Eight sick condors were taken to Liberty Wildlife in Phoenix, Arizona, for treatment. Although four of them died, the other four seem to be recovering. This is a slightly hopeful sign that at least some condors can survive exposure to this devastating virus. USFWS is also working with USDA APHIS to fast-track approval for vaccinating condors.
Ways to help
I’ll leave you with some official guidance from US Fish & Wildlife Service:
• Report bird mortalities to your state wildlife management agency immediately so that bird die-offs can be investigated and tested for avian influenza: Report dead wild birds in Arizona and dead wild birds in Utah to lo-cal DWR offices, or call USDA 1-866-536-7593.
• Please follow the below guidance to help limit the spread of the virus and avoid bird-human contact: To report dead or sick animals, please contact your state wildlife agency.
• Keep your family, including pets, a safe distance away from wildlife.
• Do not feed, handle, or approach sick or dead animals or their droppings.
• Always wash your hands after working or playing outside.
• Prevent contact of domestic or captive birds with wild birds.
• Leave young animals alone. Often, the parent animals are close by and will return for their young. For guidance on orphaned or injured wild birds, please contact your nearest wildlife rehabilitation center, state wildlife agency, or local land management agency.
• USDA also has biosecurity guidance for people who keep backyard poultry
Johanna A. Harvey, Jennifer M. Mullinax, Michael C. Runge, Diann J. Prosser. 2023. The changing dynamics of highly pathogenic avian influenza H5N1: Next steps for management & science in North America, Biological Conservation, Volume 282, 110041, ISSN 0006-3207, https://doi.org/10.1016/j.biocon.2023.110041.
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