Urgent Warning for Seabirds as Bird Flu Spreads Globally
Climate change, pollution, and accidental harm from hunting tools are not the only threats facing seabirds. A new and deadly danger has emerged: bird flu. The H5N1 strain, a highly pathogenic avian influenza, has caused thousands of deaths in the northern hemisphere over the past two years and is now moving southward. It has appeared in regions where it had not been detected before, with recent outbreaks predominantly hitting seabird colonies, a surprising pattern that has surprised researchers and conservationists alike.
Spain is among the countries confronting this crisis with urgency. Since October 1, there have been 128 observed cases of avian influenza in wild birds, including 15 cases in the last two months. Affected species range from the black-headed gull and the common tern to the gull-billed tern, peregrine falcon, little tern, pagen, and yellow-legged gull. The situation is serious for species that are especially vulnerable to infection, including the Sandwich tern and the Black-billed Shrimp, whose mortality has been reported in key habitats like the Albufera de Valencia natural park.
In response, SEO/BirdLife stresses the need to strengthen seabird conservation to bolster resilience against disease and to invite broad citizen engagement through citizen science programs such as ICAO. These programs can yield valuable data on how the disease spreads and affects seabird populations, helping researchers detect trends and respond quickly.
The global picture of avian influenza with zoonotic potential has been tracked since October 1, 2022, with assessments from international organizations highlighting ongoing risks to both wildlife and poultry sectors.
Avian influenza began as a poultry issue and began appearing in wild species across Europe at the start of the century, following migratory routes. Since then, sporadic mass mortality events among primarily aquatic birds have been noted. The emergence of the highly pathogenic H5N1 strain in seabirds in 2021 marked an unprecedented turning point that continues to unfold today.
Devastating effect
The disease crosses borders and many bird species are affected. Across the globe, about 400 species of birds have been found with the virus. The colonial lifestyle of seabirds such as gannets and terns during breeding seasons creates perfect conditions for rapid transmission. These colonies host a large share of the world populations of several species, so the global impact on populations can be severe.
Key data gathered so far underscore the gravity of the situation:
– Atlantic booby. Roughly three-quarters of colonies show some impact, with overall mortality around 60 percent. In Scotland, where main nesting sites lie, casualties exceed 11,000. The Bass Rock, home to the world’s largest gannet colony, has seen a dramatic 71 percent decline in occupied area and a 66 percent drop in breeding success.
– Pay big. At least 2,700 dead birds have been counted, and occupied areas in the British Isles have fallen by about 70 percent. The region shelters around 8,900 breeding pairs globally, with an estimated global mortality rate near 7 percent. Reproductive success in affected colonies during 2021 and 2022 was nearly zero, and many of the deceased were older birds over 20 years.
– Sandwich Tern. The pandemic’s reach continues to threaten this species in multiple regions, signaling broader ecosystem impacts.
– Snowflake Tern. During the 2022 outbreak, more than 20,000 dead adults were recorded in northwestern European colonies within two months, reflecting a 74 percent mortality rate among nesting populations.
– Breed Pelican. In 2022, the disease killed roughly 60 percent of the world’s largest pelican colony at Lake Prespa in Greece and affected other eastern European colonies. It is estimated that about 40 percent of the European population and 10 percent of the global population could be lost because of the outbreak.
– Laughing gull. In the United Kingdom alone, about 10,000 dead black-headed gulls have been documented, with hundreds of additional cases across several continental European countries.
Spain cannot shake off the virus
The current figures could underestimate the true scale due to challenges in locating carcasses and the fact that many colonies have not completed full year-to-year population estimates. The outlook suggests decades of potential recovery, if recovery is possible. Seabirds tend to be long-lived with slow maturation and a limited number of chicks per season, making adult survival critical for species persistence, according to experts involved in coastal conservation work.
Spain maintains a National Avian Influenza Surveillance Program to detect outbreaks early. Between July 1, 2022, and June 7, 2023, seven outbreaks occurred in domestic birds, one in captive birds, and 117 outbreaks in wild birds, reported across various autonomous communities, including Andalusia, Catalonia, Galicia, the Basque Country, Aragon, Castilla y León, Castilla La Mancha, Cantabria, Extremadura, Madrid, La Rioja, Asturias, Murcia, and the Valencian Community.
Valencia’s Albufera lagoon and the Ebro delta receive particular scrutiny for their importance to marine and waterfowl populations. The NGO notes that a substantial number of carcasses in these areas likely indicate flu involvement, though exact numbers remain uncertain. Authorities in Catalonia confirm a bird flu outbreak in the Ebro delta, and positive H5N1 results were reported in July for several Sandwich tern specimens from the Fangar peninsula.
What to do with a sick or dead bird
In response to the growing threat, surveillance and biosecurity measures in poultry operations have been strengthened to minimize contact with wild birds. Monitoring of seabird colonies has intensified to gauge disease incidence. Conservationists emphasize that strong leadership and targeted management actions are essential to prevent contamination of highly sensitive species.
Human transmission, though rare and usually mild, remains a concern. Handling and disposal of sick or dead birds should be performed by trained personnel with proper protective equipment to reduce zoonotic risk.
Steps to take if a sick or dead bird is found:
– Do not touch the birds that are dead or diseased.
– Keep pets away from dead or sick birds.
– Do not lure birds with water activities or feed them.
– Do not handle feathers from wild birds or surfaces contaminated with droppings.
– If poultry is present, wash hands and clean and disinfect footwear before handling birds.
– Call emergency services or contact a wildlife rescue center and follow their instructions. Trained environmental agents will respond to retrieve the animal or its carcass.
– Submit observation data to contribute to a better understanding of seabird mortality through the ICAO app, available for Android and iOS.
The latest FAO assessments continue to monitor the situation and guide policy as the year progresses, focusing on practical steps to protect wild seabirds and reduce the risk to human health and livelihoods.