Spanish authorities have confirmed four outbreaks of avian flu among wild birds in central Madrid, where forestry agents have collected hundreds of dead storks in recent weeks.
That number includes more than 100 in the past 24 hours alone.
The incidents are part of an unprecedented surge in avian influenza cases across Europe this season.
The European Food Safety Authority (EFSA) has reported thousands of wild bird infections in 29 countries.
Madrid’s regional government said that no commercial poultry farms have been affected to date, and there is no serious risk to humans.
“The authorities are removing carcasses using strict biosecurity measures to prevent further spread of the virus,” a statement said.
The storks, migratory birds arriving from northern Europe, are believed to be carrying the virus.
Highly pathogenic avian influenza has led to the culling of hundreds of millions of farmed birds globally in recent years, causing disruptions to food supplies and driving up prices. Human cases, however, remain rare.
Miguel Higueras Ortega, head of forestry operations in Madrid, said: “Based on how the outbreak is behaving in Spain and across Europe, there is no serious risk to human health, as no cases of transmission to people have been recorded.”
He added that the outbreaks did not currently appear to pose an environmental threat.
While bird flu outbreaks typically peak in autumn with migratory patterns, this season has witnessed an earlier onset, causing significant mortality among wild bird populations.
Common cranes along routes spanning Germany, France, and Spain have been particularly affected, alongside numerous waterfowl.
The EFSA said between 6 September and 28 November, there were 2,896 detections of the highly pathogenic H5 avian influenza virus – predominantly H5N1 – across 29 European nations.
Of these, 442 cases were identified in poultry, with a substantial 2,454 found in wild birds.
