The planet is experiencing a new “silent SpringDevastation of wildlife due to the death of large numbers of wild birds from avian influenza, according to a leading scientist who says the past year saw the most significant and sudden loss of birds in decades.
James Pearce-Higgins, Director of the Organization for Science British Trust for Ornithologycommented: “The last time we experienced such a large-scale and rapid loss of wild birds in the UK was the DDT effect on birds of prey in the 1950s and 1960s, linked to the legend. silent Spring, or the general decline of farmed birds during the 1970s and 1980s as a result of agricultural intensification”.
narrative of silent Spring refers to Rachel Carson’s seminal 1962 book on how pesticides, specifically insecticides, DDTThey were killing birds. DDT This caused the eggshells to become so thin that the adults crushed them during the incubation period, destroying nests and killing thousands of birds.
The World Organization for Animal Health estimates that since October 2021, more than 50,000 wild birds have died from highly pathogenic H5N1 avian influenza, mainly in Europe and the Americas. However, experts say this is a gross underestimate. In the UK alone, the number could be in the hundreds of thousands, although environmentalists say the true impact is still unknown, and most are unwilling to speculate.
In the UK, the consequences of avian influenza first appeared on the northernmost islands of Scotland in the spring, then spread up the east coast of England to Sussex, where nesting seabirds were most affected.
There are already more than a dozen outbreaks across the country among winter-migrating waterfowl. This suggests it has already spread and will be found again in breeding seabird colonies next year, Pierce-Higgins explained.
In the 2021-2022 season, there were more than 3,500 detections of the virus in wild birds across Europe, with 63 wild bird species reported from 37 countries, according to an avian influenza summary published by the European Food Safety Authority. . In the case of wild birds, Germany, France, the Netherlands and the United Kingdom reported the highest number of cases, most of which came from coastal areas, as seabirds were the most affected.
The first US case of this current outbreak was reported on January 14, 2022, in a pigeon duck in South Carolina. Since then, 3,700 positive tests have been found in 47 states, according to data from the Centers for Disease Control. Disease control and prevention of the United States
However, the tests should not be considered an indicator of impact, as only a fraction of birds that die will be collected and sent for laboratory testing, the researchers point out. “The reported figures are probably an underestimate,” said Michelle Wiley of the University of Sydney.
“For example, of the approximately 8,000 sandwich terns that died in the Netherlands, only a few are included in official statistics, in which case there is a difference of more than 200x between reported and observed numbers. The lack of appreciation is concerning, as it can have an impact at the species/population level.
Globally, most reports come from Europe and then the Americas, according to UN mapping data, although the disease has also spread to Africa and Asia. In November this year, avian influenza was detected in South America, and there are fears it will reach the Galapagos Islands.
Scientists suspect that a migrant Franklin’s gull introduced the H5N1 subtype from the United States. More than 13,000 seabirds were killed in Peru, including more than 5,500 pelicans.
It has since spread to five South American countries, according to the Pan American Health Organization. “The recent outbreak of highly pathogenic avian influenza off the coast of Peru is a serious situation … Evidence has shown the potential for the virus to spread to other groups of birds,” said Luis Germán Naranjo, conservation director for WWF Colombia.
About 60% of the world’s population of great skuas and northern gannets live in Britain. Both species have suffered “unprecedented levels of mortality,” Pierce-Higgins said, and their populations are likely to be affected for decades because they are long-lived and slow-reproducing species.
Experts say the picture will become clearer in the coming years as we look at how many migratory seabirds return to breed, which will help determine how many have died.