A new epidemic is (currently) hitting birds around the world

Atlantic gannets have been found dead on a beach in Granada. © Juan Perez Contreras

A virus is back and scaring us, bird flu, better known as H5N1 influenza virus. It is an infectious disease, birds are being wiped out, wild and domestic. It has been known for over 100 years, but has gradually spread throughout the world, killing millions of birds.

Avian influenza is currently an animal disease that spreads among birds, From birds to people are exceptions. Still, experts are not ruling out the possibility that the virus could mutate and lead to a pandemic.

Currently, as the Ministry of Health points out, the number of human cases remains very low compared to the total number of affected birds. But for birds, it would be a truly global catastrophe.

Global distribution of avian influenza viruses as of 1 October 2022. Global AIV with zoonotic potential (fao.org)

Seabirds, most affected

The virus, which affects poultry, began to be detected in wild species in the early 2000s and spread along the birds’ migratory routes, SEO/BirdLife reported. Since then, there have been sporadic mass die-offs in wetlands across the continent, mainly of aquatic birds, and more or less seasonally.However, the 2021 highly pathogenic avian influenza H5N1 subtype virus leap to seabirdresulting in an unprecedented situation that continues to this day.

In Europe, populations of black-headed gulls and more recently kittiwakes and guillemots are most susceptible to the virus, and there are concerns about their rapid expansion and adaptation to new hosts.

Impact on European seabird populations

At present, bird flu virus has been found in some areas. 400 different bird speciesBut outbreaks over the past two years have mostly affected seabirds, which is unusual for now.

The group behavior of species such as gannets and terns during breeding creates the perfect scenario for the rapid spread of the virus. Adults come ashore only once a year for several months to build nests, usually congregating on remote islets or bays. This means that these colonies house a significant portion of the world’s population for some of these species, so the impact on their global population is devastating.Some of the data collected so far show that Emergency moment:

  • atlantic gannet. At least 75% of existing colonies are affected, with an overall mortality rate of 60%. More than 11,000 casualties are estimated in Scotland, their main nesting ground. In Bas Rock, the largest gannet colony in the world, occupied territory decreased by 71% and reproductive success dropped by 66% (see graph).
  • pay big money They counted at least 2,700 dead bodies and one dead body. British Isles Occupied Territory reduced by 70%, the major group is distributed worldwide (approximately 8,900 pairs), with an estimated mortality rate of 7% of the global population. In 2021 and 2022, the reproductive success of affected populations will be close to zero. Several of the dead birds were over 20 years old.
  • Sandwich Tern. During the outbreak in 2022, a total of 20,531 adults died in just two monthscalculating a mortality rate of 74% for the nesting population.
  • eyebrow pelican. 2022 flu causes 60% of the world’s largest population in Lake Prespa (Greece) died, also affecting other colonies in Eastern Europe. It is estimated that the European population will decrease by 40% and the global population by 10%.
  • black headed gull.some are calculated 10,000 black-headed gulls die in UKaccounting for 4% of its population, with hundreds more cases across continental Europe.

The impact of influenza on the gannet colony of Bass Rock, Scotland, a small island of more than 150,000 nesting birds. https://www.seabird.org/threats/disease

underestimated figures

Because animal carcasses are difficult to recover, and long-term population estimates that allow year-to-year comparisons are not available for all colonies, these figures are likely gross underestimates.

“It will take decades for these populations to recover, if they are successful,” said Lucía Soliño, SEO/BirdLife Marine Program technical staff. “The fact that it mainly affects breeding individuals is a serious problem for these populations. hit, which goes beyond the immediate death rate and doesn’t appear to be abating in the coming months.”

Data on the possible immunity of birds to the disease is still sparse. In gannets, the darkening of the iris observed in some apparently healthy individuals may be related to overcoming the disease, although it is unclear how this change in the eye affects their vision and chances of long-term survival.

spanish bird flu

Spain has a national avian influenza surveillance program aimed at early detection of the disease, which includes immediate notification and investigation by official veterinary services of any signs of illness or death in poultry, as well as regular sampling on certain farms depending on risk.

During this epidemic period, from July 1, 2022 to June 7, 2023 7 outbreaks found in poultry1 captive birds and 117 cases of wild birds Andalusia, Catalonia, Galicia, Basque Country, Aragon, Castilla-Leon, Castilla-La Mancha, Cantabria , Extremadura, Madrid, La Rioja, Asturias, Murcia and Valencia.

The outbreaks in Valencia’s Albufeira and Ebro Delta Natural Parks are of particular concern, both of which are extremely important for marine and waterfowl.First they have withdrawn More than 1,000 carcasses of sandwich terns and black-billed squirrelsbut it is unclear how many are due to the flu.

Faced with this situation, poultry farms have stepped up surveillance and biosecurity measures, especially measures to avoid contact with wild birds. Surveillance of seabird populations has also been intensified to quantify the incidence of the disease. However, in the face of a pandemic of this magnitude, extreme precautions and appropriate management measures are necessary to avoid transmission to the most sensitive species.

Volunteers use the ICAO app to record data on shore birds. © Oriol Allamani

Citizens help spot new cases

Citizen science actions can be very useful for early detection of new bird flu outbreaks or other causes of seabird mortality, which is why SEO/BirdLife has launched the ICAO (Coastal Inspection of Coastal Birds) mobile app in 2021, available at Totally free in three languages ​​(Spanish, Portuguese and French) for Android and IOS.

The app allows you to send data on birds and other marine animals found on the coast, dead or alive, with signs of illness/injury. Two types of observations can be selected: observations along transects (ICAO Walk) or as point observations. Observations and photos can also be uploaded through the ICAO website https://icao.seo.org/ where you can also consult all user-supplied information that has been previously reviewed and verified by professionals at SEO/ . Society for the Protection of Birds.

The app is particularly useful for documenting mass bird die-offs, such as the winter of 2022 off the Mediterranean coast, where 158 registered razorbills were stranded, and the January 2023 event in the Atlantic, during which 359 puffins. Discover the Iberian Atlantic and Cantabrian coasts with the app.

What to do if you find a sick or dead bird

  • Avoid contact with birds. Although cases of transmission to humans have so far been rare and of low severity, to avoid the risk of zoonotic disease, handling and eradication of birds must be carried out by specialized personnel and personal protective equipment. If you walk with your dog, keep it on a leash and out of sight to prevent it from swallowing dead animal parts or causing discomfort to sick animals.
  • Dial 112 or Appropriate provincial CRF Animal Recovery Center and follow instructions. Conservation staff will go to designated locations to collect the animals or their carcasses.
  • Send observation data through the application If you would like to contribute to SEO/BirdLife to improve understanding of causes of seabird mortality, ICAO is available for Android and IOS (Apple).

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