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Cranes die from avian flu: ornithologists suspect factory farms
By Fabienne Loiseau
November 15, 2025 at 9:00 AM
Reading time: 7 minutes
While avian flu has killed thousands of common cranes in the past month, authorities are worried about poultry. Ornithologists, on the other hand, suspect that industrial farms are the cause of this mass die-off.
Broken slates and a gaping hole in the roof. On October 23rd, a house in Aix-d'Angillon, in the Cher department, was damaged by a falling… common crane. Recovered by the French Office for Biodiversity, the bird tested positive for highly pathogenic avian influenza ( HPAI ).
“ We are facing a sad deluge of birds with the flu ,” Jean-Noël Rieffel, regional director of the French Office for Biodiversity ( OFB ) Centre-Val de Loire, confirmed to Reporterre . In other regions, cranes have fallen onto highways and into schoolyards, he added.
For the past month, the carcasses of approximately 25,000 common cranes have been found along their migratory route through Germany, France, and Spain, according to Alain Salvi, president of the European Crane Working Group. The count is estimated to exceed 10,000 in France alone. " And these are only the birds that have been observed. Many others have undoubtedly disappeared, either drowned or eaten by predators , " explains Salvi, who is also president of the Lorraine Regional Nature Reserve.
Every autumn, 350,000 to 400,000 common cranes fly over our country in shifting V-shaped formations, announcing the first cold weather with their characteristic " krrrrou, krrrrou " . About a third do not go any further and remain to overwinter at stopover sites, in Champagne-Ardenne ( Lac du Der ), in the large alluvial valleys of the Loire and Allier rivers (Nièvre, Cher, Allier) or in the Landes region (Arjuzanx nature reserve).
These large, gray, and shy birds will be less numerous in our fields this winter. Even so, Alain Savi offers reassurance: the current epizootic should not unduly affect the renewal of crane populations, whose numbers are already satisfactory.
1.5 million farm animals affected in Germany
It was in Germany that the epidemic started during the second week of October. Originating in the far northeast of Germany, it then spread southwest following the migratory route of crane flies.
In addition to the thousands of cranes that have been collected, the H5N1 virus has also been causing a massive die-off in poultry farms for the past month. According to the Friedrich-Loeffler Institute, the German authority responsible for epizootic diseases, as of November 12, approximately 1.5 million farm animals had died from the virus or had been culled as a preventative measure.
Clusters of infection in France
On the same date, in France, the Ministry of Agriculture reported 18 outbreaks of avian influenza in commercial turkey, duck, and chicken farms, without providing the total number of birds killed or culled. Precautionary and biosecurity measures on farms have been reinforced since October 22nd, as the risk level for avian influenza was raised from " moderate " to " high " .
" The sharp increase in the incidence of poultry outbreaks in northern and western Germany observed since mid-October 2025 suggests a significant change in the dynamics of HPAI virus infection . It is probably linked to the ongoing post-nuptial migration and mass mortality events observed in common cranes , " the scientists write in the Weekly Bulletin of International Animal Health Surveillance ( BHVSI - SA ).
In other words, the virus could have been introduced into the farms by cranes that were already infected. However, this hypothesis is being questioned by ornithologists and environmental groups in Germany.
" It has not yet been proven that wild birds are the source of the outbreaks ."
The branch of the German Union for Nature Conservation and Biodiversity in Brandenburg — one of the most affected regions — suspects , on the contrary, that the poultry industry is the cause of the crane contamination, and demands a transparent investigation to understand the source of the infection, through a petition signed by nearly 100,000 people.
" It has not yet been proven that wild birds are the source of the outbreaks of highly pathogenic avian influenza H5N1 ," the organization stated. " It is more likely that wild birds are infected by viruses that previously circulated in the poultry industry. " It noted that the virus had been officially detected in 15 poultry farms across five German states even before the first cranes had died.
Most of these infected farms are enclosed, with no access to the outdoors for the poultry, notes Klemens Steiof, a Berlin-based ornithologist interviewed by Reporterre . He finds it " extremely unlikely " that cranes could have contaminated such places .
The greylag geese were spared
Furthermore, the naturalist believes that an infected wild bird that dies no longer spreads the virus, which is quickly destroyed in nature. He gives the example of wild geese: " Currently, in Germany, common cranes have not infected the tens of thousands of greylag geese, bean geese, and white-fronted geese that share the same habitat. "
According to him, the transmission of this virus from wild birds to other birds only occurs in very specific situations: densely populated seabird colonies, large gatherings of cranes in roosts, predatory or scavenger birds feeding on an infected bird… This is also the fear of Alain Salvi in Lorraine, a region that is home to the rare white-tailed eagles of France: “ They could become infected by feeding on the carcasses of cranes. ”
Contaminated manure spread in the fields ?
But how could the virus have passed from an enclosed farm to wild cranes ? " Unfortunately, veterinarians do not usually look for vectors between the poultry industry and wild birds , " laments Klemens Steiof, who can only offer hypotheses.
The fact that the epidemic began intensely, with many cranes infected within a few days, suggests, according to him, a source close to the large crane parking sites located in eastern Germany (Mecklenburg-Western Pomerania and/or Brandenburg).
Another factor that could explain why only the cranes were affected and not other wild birds: " One possibility could be the fertilization of the cornfields, which are numerous in Brandenburg, with manure from livestock farms that has been buried in the soil , " he suggests. While the cranes forage in the soil in search of remaining corn kernels, the wild geese would simply peck at the surface.
He also mentions the possibility of contamination from ventilation systems. Finally, the transport of infected poultry to slaughterhouses could be another potential source of contamination along the route.
" It's easy to blame wild birds and turn a blind eye to factory farming ."
" We demand that the spreading of manure on fields be permitted only after germicidal treatment , " demands Helmut Brücher, a member of the board of directors of the Bund für Natur und Umwelt (Friends of the Earth Germany) branch in Brandenburg.
" It is easy to blame wild birds and turn a blind eye to industrial farming and its consequences. Brandenburg has the largest egg-laying hen farms in Germany, with an average of more than 60,000 animals , " he denounces, calling for more in-depth investigations into large farms.
In France, the League for the Protection of Birds expressed the same position in a statement at the end of October: " As formidable incubators of viruses, high concentrations of poultry promote the emergence of new, potentially more aggressive variants, likely to threaten all living things, including humans. "
The association is once again denouncing the Duplomb law , condemned by all environmentalists, which eases regulations by raising the thresholds above which intensive poultry farms are subject to environmental authorization. " France is unfortunately moving in the wrong direction , " concludes Allain Bougrain-Dubourg, its president.
https://reporterre.net/Grippe-aviai...e-contaminees-par-les-elevages-industriels-et
