Study Finds Black Irises in Northern Gannets May Indicate Recovery from Avian Influenza

A new pre-print study published last week revealed that the irises of Northern Gannets, a type of seabird, turn black if they recover from the highly pathogenic H5N1 avian influenza. Northern Gannets were one of the species severely impacted by the ongoing bird flu outbreak affecting Europe and the Americas. The study examined Gannets at Bass Rock in the UK and discovered that black irises may serve as a likely indicator of prior infection with avian influenza. The researchers added that the one infected bird with blue irises may have been infected with a different subtype of avian influenza, waning antibody levels, or it may be that not all infected birds develop black irises. According to the RSPB, outbreaks of avian influenza were recorded last year in Iceland, Scotland, Canada, Germany, and Norway, including at Bass Rock, the world’s largest Gannet colony. The study was conducted by researchers from the RSPB, the University of Glasgow, the University of Edinburgh, Heriot Watt University, and the Animal Plant Health Agency in partnership with the Scottish Seabird Centre.