Avian influenza

About the 2021/ 2022 HPAI outbreak

Background and origins

Over the winter of 2021 and 2022 an outbreak of HPAI was confirmed in Barnacle Geese wintering on the Solway Firth.

Barnacle Geese (Canva)

These birds were from the Svalbard breeding population and it has been estimated that many thousands of individuals died as a result.

• Previous outbreaks of HPAI have tended to hit wintering waterfowl, subsiding as wintering flocks disperse.
• Unusually, on this occasion, the HPAI virus (subtype H5N1) spread into our globally important colonies of nesting seabirds. Monitoring work carried out by the Animal and Plant Health Agency (APHA) has also confirmed HPAI in other (non-seabird) species including raptors, wildfowl, waders, gamebirds and others.

Impact on breeding seabirds

From late spring 2022, increasing numbers of reports of the disease were received from seabird colonies around the northern UK.

Gannet colony. Edmund Fellowes / BTO

Very large numbers of breeding seabirds, including significant numbers of Great Skuas and Gannets, are thought to have died as a result. Further south, breeding tern colonies were also impacted by the outbreak.

• More than 2,200 Great Skua deaths (equivalent to 11% of the British and 7% of the world population) have already been reported by NatureScot, including 1,000+ from the largest colony of Foula (Falchieri et al. 2022).
• Gannet mortalities also appear widespread, from Alderney in the Channel Islands in the south to Noss, Shetland, in the north.

Looking ahead: migration and the impact of AI on wintering waterfowl

Given the usual vulnerability of waterbirds to the disease, the autumn and winter is a period of particular concern because Britain and Ireland host important wintering waterfowl populations and are part of a wider flyway that links populations from many different breeding areas.

The potential for migratory birds to spread the disease across continents is highlighted by recent evidence from North America (Caliendo et al. 2022).

• This is why BTO has been developing the migration mapping tool to help quantify this risk.

What is BTO doing to help tackle HPAI?

As the custodian and coordinator of national datasets of wild bird populations, including their abundance, distributions, and demographics, we are uniquely placed to provide insights and commentary on this issue.

Collaborative science

We are working with the Joint Nature Conservation Committee, Country Nature Conservation Bodies (CNCBs), DEFRA, APHA, Scottish Government, RSPB, and other NGOs and administrations to understand the impacts on bird populations and how to tackle the avian flu challenge.

Our scientists have coordinated regular meetings with these other organisations, sharing our expertise and data, so that efforts to tackle the outbreak and address its longer-term impacts are informed by the available evidence.

Utilising volunteer data

Maintaining, supporting and growing our network of volunteers provides a vital service to the wider conservation community and provides crucial information for a wide array of uses, including the assessment of HPAI impacts.

Thanks to the efforts of birdwatchers using BirdTrack, our volunteers and supporters, on the ground responses to the virus are informed by the best available evidence of wildbird numbers and movements.

• This information is used to assess the current risk that avian influenza poses to different species groups, which is used to guide BTO ringing activities. 

Assessing vulnerability of bird species

BTO staff are carrying out vulnerability assessments, identifying those species and populations at greatest risk from the outbreak. This information will help to inform conservation responses and the prioritisation of resources.

Our modelling work will help to reveal the likely medium-term impacts of the outbreak on populations, and the risk that future outbreaks may pose to their future conservation status and in some cases, extinction risk.

• This is particularly relevant in the case of our breeding seabirds, which tend to be long-lived, slow to reach sexual maturity and, as a consequence, slow to recover from substantial losses.

Informing future planning and decision-making

We have been developing tools to inform future planning and decision-making. Through a collaboration between EURING and EuroBirdPortal, funded by the European Food Safety Authority (EFSA), BTO has developed a migration mapping tool to inform the management of future Avian Influenza outbreaks.

• This approach can be extended to develop predictive models of AI spread in domestic birds based on wild bird abundance and movements across Europe.

Informing our supporters

Our membership magazines, other supporter communications and social media feeds continue to carry articles and updates about HPAI and our response to it. These include a blog post published in mid July and articles in our membership magazine, one on the impact of the outbreak and one demonstrating the value of the monitoring tools we have in place.

We have done a lot to respond to this crisis and our plans are to continue to play as big a role as we can in helping to safeguard bird populations and assist with their recovery.

• We will provide supporters with regular updates about developments in this area and, in particular, about the progress we are making to help.

Funding our work

We are funding this work both from our core funds, from scheme budgets, and through targeted fundraising efforts. An approach to major donors was mailed in August 2022, and a wider fundraising appeal was mailed to our supporters in November 2022.

Frequently asked questions

• If you have questions about the health and hygiene aspects of avian influenza, please see our information about the additional health and safety risks associated with avian flu.

What should I do if I find a dead bird?

Birdwatchers can be of great assistance in staying alert for unusual cases of mortality or sickness in wild birds. Many thousands of birds die every week of natural causes and so it is not unusual to occasionally find dead individuals.

• Please report dead wild birds to Defra for testing follow the latest guidance on the GOV.UK webpage: Report dead wild birds or to DAERA in Northern Ireland.
• If you know the species, please ALSO report dead wild birds on BirdTrack to help assess population impacts.

If you want to submit a report without providing contact details, phone Defra on 03459 33 55 77. In Northern Ireland, wild bird mortality incidents should be reported to the DAERA Helpline: 0300 200 7840.

Helpline staff will be able to advise you on whether a response is required e.g. whether the bodies be collected by a representative for testing; not all birds are tested, but collating sightings may reveal patterns of mortality.

Some key sites have been selected to collect more detailed information on wild bird mortality via the Epicollect systems. These Epicollect sites are contacted by the relevant SNCBs (Natural England, Natural Resources Wales, NatureScot, NIEA) with details.

Where possible, avoid directly touching any dead birds. If you move a dead bird e.g. if a cat brings one into your house or you need to check if it is ringed, invert a plastic bag over your hand and pick the bird up in the plastic.

If the bird is ringed, report the ring details to BTO using the EURING website, then draw the bag over your hand and tie it up and dispose of it in your usual household waste, and wash your hands with soap and water.