(CTN News) – In the latest bird flu outbreak, researchers have raised alarming concerns as millions of wild birds worldwide are suspected to have died. South America, in particular, has been severely affected, with Peru reporting a staggering 200,000 deaths.
The highly infectious variant of H5N1 gained momentum in the winter of 2021, causing Europe’s worst bird flu outbreak before rapidly spreading across the globe. Bird flu cases have been reported on every continent except Oceania and Antarctica.
Estimating the exact number of wild bird deaths is challenging due to the large number of uncounted carcasses. A groundbreaking research co-authored by Michelle Wille from the University of Sydney has attempted the first global assessment of bird flu-related mortality since October 2021.
The study suggests that the death toll among wild birds is likely in the millions, surpassing the previously reported tens of thousands.
The outbreak’s impact on wild bird populations raises serious concerns about potential species extinctions and threatens decades of conservation efforts.
Several regions have witnessed significant population declines, such as the 17% mortality rate among sandwich terns in Europe in 2022, 40% of Dalmatian pelicans in southeastern Europe in 2021, and 62% of Caspian terns breeding on Lake Michigan in 2022.
Having experienced bird flu for the first time, South America has been particularly hard hit, with notable fatalities among Peruvian pelicans, boobies, and cormorants. The situation remains distressing, especially with the virus reaching Tierra del Fuego, raising concerns about its potential emergence in Antarctica.
Some countries like Peru have been more proactive in reporting bird flu cases, while others have been less transparent.
The UK’s Animal and Plant Health Agency director, Ian Brown, notes that Brazil, a major chicken meat exporter, took six months to confirm cases in wild birds after Peru’s reports. Limited resources in some countries also hinder comprehensive reporting on the virus’s impact.
The global spread of bird flu has become a game-changer, with Indonesia detecting the disease, raising concerns about its potential reach in Australia.
The virus’s presence in Europe during the second breeding season has affected different bird species compared to the previous year. For instance, black-headed gulls and terns have been heavily impacted, with at least 30,000 dead individuals in the UK alone.
Researchers are still trying to understand the affected birds’ recovery rate and immunity. Early findings indicate that some species, like gannets, may exhibit signs of immunity based on eye coloration.
With numerous outbreaks and bird deaths being reported worldwide, the impact of last year’s outbreak on bird populations is evident, affecting the number of birds returning this year.
Scotland, home to 60% of the world’s great skuas, has experienced significant breeding population declines, with 90% of the birds potentially lost in some reserves.
Despite Europe having more reported cases, gaps in surveillance data in other regions may indicate the virus’s presence.
As the current strain of H5N1 remains a pressing international crisis, researchers and authorities are faced with the urgent task of mitigating the outbreak’s devastating consequences on wild bird populations.