USGS
12 March 2026
The ongoing H5N1 outbreak continues to impact a wide range of wild bird species, prompting heightened surveillance and biosafety measures across North America.
The U.S. Geological Survey (USGS) National Wildlife Health Center (NWHC) reports that Highly Pathogenic Avian Influenza (HPAI) H5N1 remains a significant threat to wildlife, with detections confirmed in all four major U.S. flyways. Since its emergence in late 2021, this particular strain has exhibited unusual persistence, affecting not only waterfowl but also raptors, colonial nesting seabirds, and several mammalian species.
Data indicates that while migratory patterns often dictate the spread of the virus, the current H5N1 lineage has demonstrated a heightened ability to circulate during non-migratory seasons. This year-round presence has led to significant mortality events in diverse populations, raising concerns among conservationists regarding the long-term impact on biodiversity and the health of sensitive ecosystems.
