Scottish wild bird high pathogenicity: avian influenza response plan

8. HPAI in wild birds - research and monitoring

The integration of surveillance activities with research is essential to improve our understanding of avian influenza in wild bird populations. This includes presence of the virus in the environment; monitoring the impact to wild bird populations and prevention of spread within wild bird populations. This section highlights areas of research and knowledge gaps that remain.

8.1. Monitoring levels of infection of HPAI in wild birds

A critical component of the response to HPAI in wild birds is understanding how the disease is moving through a population and whether birds have developed a level of immunity to (the current strain of) HPAI (e.g., if the majority of the birds have encountered HPAI and have survived).

In June 2022 a consortium of UK scientists initiated a project that followed on from the ‘FluMap’ consortia to utilise tools and relationships developed under ‘FluMap’ in a new project termed ‘FluTrailMap’. This project aims to enhance understanding of how HPAI is emerging in wild avian populations and define risk pathways posed to both domestic and wild birds from HPAIV, including why some bird species are more resistant to HPAIVs.

In August 2024, the Defra funded ‘iPREPARE; Influenza Preparedness and Planning for Animal Risks of Emerging Threats’ project was initiated. This project links numerous academic^[10] and non-academic organisations^[11] to assess healthy birds for notifiable and non-notifiable avian influenza viruses, supported by APHA NRL (Weybridge). The project extends across all bird species as well as mammalian species where risk of infection has been seen. The project also aims to map behaviours and infection potential of different species as well as assess different subtypes and genotypes of HPAIVs in avian species.

Ongoing monitoring and reporting of dead or sick wild birds in combination with testing for HPAI, allows the distribution, spread, virus strain and any seasonality of infection and mortality to be identified. Alongside the GB avian influenza dead wild bird surveillance scheme, NatureScot, in discussion with APHA and Scottish Government, identified priority areas for surveillance, thereby providing further intelligence and data on circulation in wild birds to aid conservation management.

NatureScot continues to undertake targeted reporting using Epicollect (Figure 2). This targets key sites and its primary aim is to provide real time intelligence on how the outbreak may be developing. In addition, the British Trust for Ornithology (BTO) have modified the BirdTrack software and mobile app to allow reporting of dead birds by the public. This does not replace the online reporting system or the GB telephone (03459 33 55 77) to report dead wild birds. This continued monitoring, as with those schemes stated above, provides further data to monitor the spread of the outbreak and aid conservation.

Summary:

• The provision of real time testing in specific colonies would help monitor any developing outbreak.
• Understanding how HPAI is circulating in live wild birds could increase understanding of its longer-term impacts. Specifically, in order to contribute to better targeted conservation management, it would be useful to understand the ability of specific species to develop resistance. Serological testing of apparently healthy birds will allow estimates of recovery rates from infection and focus management at colonies to aid in species recovery. This work is being undertaken under the ECOFLU and iPREPARE project led by University of Edinburgh through supportive links with the APHA NRL (Weybridge).

The University of Edinburgh is leading the NERC funded project ECOFLU: Understanding the ecology of High Pathogenicity Avian Influenza in wild bird populations. This project supports a wide range of researchers and stakeholders to address the impact of the epizootic in wild bird populations with a view to identifying mitigations where these can be put in place, including species of conservation priority (e.g., Greenland and Svalbard barnacle geese, great skua and gulls).

This data may help to aid understanding of disease resistance and transmission, and therefore the potential future risk to wild bird populations.

The APHA NRL (Weybridge) are developing work to undertake increased serological testing of wild birds during an outbreak over and above that undertaken through the GB dead wild bird surveillance scheme. This work is currently funded through the iPREPARE project that runs until March 2026.

Ad-hoc serological surveys is also performed on live and shot wild birds and mammals through Flutrail map, ECOFLU and iPREPARE.

8.2. Specified animal pathogen testing

Certain avian influenza viruses including Influenza A (H5N1) are Specified Animal Pathogens (as set out in Scotland by The Specified Animal Pathogens (Scotland) Order 2009 (as amended) and can therefore only be handled in a facility with an appropriate Specified Animal Pathogen Order (SAPO) containment level 4 licence.

All diagnostic testing for Influenza Type A viruses from animals in scope of official controls or other official activities (as defined by the Official Control Regulations (OCR) (EU Reg 2017/625; amended and retained in UK legislation under SI 2020/1481) must be undertaken at either a National Reference Laboratory (NRL) or an official laboratory designated for a relevant purpose.

The UK NRL for avian influenza is:

Animal and Plant Health Agency (APHA) Weybridge Laboratory Woodham Lane Addlestone KT15 3NB England

The APHA Weybridge laboratory is also an Avian Influenza International Reference Laboratory (IRL)( FluGlobalNet - Home). It is designated as a World Organisation for Animal Health (WOAH) avian influenza reference laboratory and a Food and Agriculture Organisation (FAO) Reference Centre for Animal Influenza.

8.2. Surveillance of other wildlife

The avian influenza dead wild bird surveillance scheme is designed to be flexible in terms of the species of birds that are routinely tested based on current evidence across the EU and other countries. The current focus is targeted towards wild migratory wildfowl (such as geese, ducks, swans), gulls, raptors and seabirds. The reporting criteria is continually reviewed and is readily adaptable to accommodate any changes deemed appropriate by ADPG to the list of susceptible species ^[12].

It is recognised that this reporting criteria relies on the reporting of dead wild birds by members of the public, but the scheme was designed to meet the policy requirements (i.e., the species that play an active role in the epidemiology of HPAI). The threshold for inclusions within the list is low, meaning the species on the list are relevant to the contribution to the epidemiology.

Surveillance testing is also carried out by APHA NRL (Weybridge) on mammalian species to track the spread of HPAIV. The current target list includes carnivora (e.g. mustelids, canids, felids etc), including badgers and otters, as well as marine mammals (pinnipeds and cetaceans). As with wild bird surveillance, the list is subject to change based on scientific advice.

Summary:

• Ongoing monitoring of the spread of the virus is critical for our wild bird populations.
• The triage of cases is continually reviewed against guidance and susceptible species lists that are agreed at an international level.

8.3. Presence of virus in the environment

Environmental sampling to detect the presence of organisms from their DNA is now an established technique in biology (eDNA). Using environmental sampling to detect HPAI could assist in estimating the likelihood of reinfection from the environment following an outbreak in wild birds. At present Scottish Government’s policy for outbreaks of HPAI in poultry is outlined in the Notifiable Avian Diseases Control Strategy for Great Britain. The Scottish Government has a policy to humanely cull poultry and other captive birds, in line with its legal and international obligation, on infected premises and to require the cleansing and disinfection of premises before re-stocking. This is clearly not logistically possible, or desirable, in wild birds where, in most cases, there is no alternative but to let the disease run its course.

Summary:

• Further evidence to understand the prevalence and presence of HPAI in the environment is needed in order to understand if there are infection routes other than from bird carcasses and faeces as this may have additional implications for non-avian species.

8.4. Monitoring population level impacts of HPAI on wild birds

The impacts of HPAI on wild bird populations are difficult to assess and quantify as impacts may be direct or indirect, and there is the potential for a lag period between these impacts and their detection through monitoring programmes. Long-term population monitoring is nevertheless crucial in understanding the (long term) impacts of avian influenza on Scotland’s wild bird populations.

Of particular concern is when avian influenza is detected in wild bird species of conservation concern, such as those listed red and amber in the UK Birds of Conservation Concern^[13] (BoCC) or on the Great Britain IUCN Red List with great skua added to the Red list owing to severe HPAI impacts^[14].

Population monitoring of seabirds in Scotland (and the rest of the UK) is coordinated by the BTO under the Seabird Monitoring Programme (SMP). The SMP in the context of baseline figures from the National Seabird Census (Seabirds Count, published in 2023) provides a critical baseline against which to understand the extent and impacts of apparent HPAI mortality.

The Royal Society for the Protection of Birds (RSPB) HPAI Seabird Survey Project, using a coordinated and collaborative approach across statutory bodies and conservation organisations, provided updated seabird population counts at targeted colonies against which to determine the impacts of HPAI (UK seabird colony counts in 2023 following the 2021-22 outbreak of Highly Pathogenic Avian Influenza.

Further to these programmes, NatureScot continues to operate a programme of work to deliver a response to HPAI outbreaks in wild birds. The objectives of this programme are:

1. To understand the impact of HPAI on internationally important bird populations, particularly seabirds, including many species which are already threatened by the impact of climate change and face catastrophic declines.

2. Ensure we have an effective testing programme in key locations to enable us to take rapid remedial action in managing access and tourist activities.

3. Provide crucial additional surveillance in remote locations not served by the GB HPAI surveillance scheme to feed into the APHA risk assessment process and provide an early warning mechanism for outbreaks in both wild birds and the poultry sector.

For a number of goose species, monitoring data are already collected on a regular basis at local, national and international scales. The two barnacle goose populations are monitored regularly, with the Svalbard population monitored annually and the Greenland population, which winters across Scotland and Ireland, monitored on a three yearly cycle. A Greenland barnacle goose population census was conducted in February 2023. The population data are fed into flyway level discussions, facilitated through the European Goose Management Platform, on species management decisions. Local data, particularly around goose management scheme locations, are fed into local decisions on management and will continue to do so.

The Scottish Raptor Monitoring Scheme currently focuses primarily on the annual monitoring of diurnal birds of prey and owls native to, and which regularly occur within, Scotland. It also monitors ravens and provides annual information on breeding, numbers and productivity.

For some species or populations, the ability to detect even large population changes may be relatively poor^[15]. Some other species that may be impacted in the future (e.g., common buzzard), are less well assessed, and our understanding of the impact of the disease on these species is more limited. Consideration should be given to whether additional monitoring of particular species is needed, and this should be kept under periodic review.

Summary:

• Existing monitoring, including under SMP, and goose monitoring programmes will continue to aid understanding of the long-term impacts of HPAI on wild bird colonies.
• As surveillance continues, consideration will be given to monitoring species that are not covered through existing programmes as necessary.
• The monitoring will have some level of flexibility to take into account any changes in circumstances during an outbreak.

8.5. HPAI transmission to and within wild bird populations

The NatureScot Scientific Advisory Committee subgroup on Avian Flu have published a report that concluded that while there is relatively little understanding of the roles of different transmission routes and the importance of environmental persistence, this deficiency is of limited management consequence as there are almost no management options contingent on this knowledge^[16]. In addition, compared to high levels of exposure generated through, within and between wild-species contact, exposure resulting from human vectoring of virus should be very small indeed. The key focus here should be on avoiding introducing virus into sites where it has been previously absent. A summary of this report can be found in Annex A.

NatureScot have developed guidance for site managers on methods to limit the spread and transmission of HPAIV by human activities. Biosecurity plans are a useful tool to educate any visitors to colonies.

Summary:

• There is currently no proposal to close access to colonies generally.
• Guidance for land managers is in place to assist in limiting transmission of the virus to other colonies.

8.6. Wider measures to mitigate the impacts of HPAI on wild birds

To assist in the recovery of HPAI impacted populations of wild birds, it may be appropriate to identify and put in place actions that have the potential to increase survival or productivity. Such measures may include the removal of pressures that cause direct mortality, or improvements to nesting or foraging habitats.

A range of initiatives are under way which will help identify the most appropriate action that could be taken to aid population recovery, thereby helping mitigate the impacts of pressures, including HPAI on wild birds. This includes the Scottish Seabird Conservation Action Plan which identifies over 50 priority actions which, if implemented, could help enhance seabird conservation status and increase their resilience to a range of pressures. Publication of the action plan is expected in summer 2025.

Furthermore, the UK Marine Wildlife Bycatch Mitigation Initiative outlines policy objectives and actions to achieve part of the Fisheries Act’s ecosystem objective, including improving our understanding of where and how much bycatch occurs and implementing effective mitigation measures to minimise and, where possible, eliminate bycatch.

The population and HPAI monitoring, discussed previously, will also help identify species or populations most in need of mitigation measures. In addition to this, NatureScot has commissioned research into the breeding success of Scottish raptors in order to identify those species most in need of support. A collaboration is underway between the University of Edinburgh and APHA to assess how levels of immunity are building up in seabird and goose populations that have been especially badly hit by the disease. This will help predict whether particular populations are likely to start to recover or whether they remain vulnerable to further losses in the months and years to come.

As well as understanding resistance to the development of disease and death in some species whilst others die in large numbers, it may be appropriate to develop research programmes that allow work to identify and target measures that can bring wider benefits to a broader range of wild bird species. This will be assessed as the outbreak continues, and plans developed as the long-term pattern of the outbreak becomes clearer and impacts better understood. As an example, liaison with range states supporting migratory goose populations through the AEWA European Goose Management Platform is ongoing and population modelling will help predict ongoing impacts and guide modulation of flyway plans.

8.7. Summary of Activities that may impact wild bird HPAI transmission and or survivability.

Activities that may impact wild birds in terms of HPAI transmission and / or survivability are kept under regular review by NatureScot and based on the latest advice.

The NatureScot Working Group reviewed a wide range of possible disturbance events:

• ways of grouping species that might be impacted by the same disturbances in similar ways,
• the mechanisms by which they may increase the spread of HPAI, and approaches to mitigation and the process required to make decisions given; and
• the costs and benefits of curtailment/modification of human activities.

There is however little available evidence to assess the impact from the diverse forms of disturbance that may influence the epidemiology of H5Nx in wild birds or to inform policy on measures that could alleviate pressures on infection and recovery.

A matrix of activities that could have a negative impact on wild birds, where HPAI has been detected, is identified below and associated with potential responses. The matrix (Table 3) includes research (e.g., bird ringing activities), access to sites, shooting and other land management activities. Currently there is no intention to restrict these activities. Any further consideration will be undertaken on a site-by-site basis.

Table 3: Matrix of activities with lead decision makers.

Scottish Government (SG) 

• Responsible for responding to, co-ordinating and managing, the disease response to outbreaks of exotic notifiable diseases in Scotland, supported by operational partners; including NatureScot, with regards to environmental and wildlife impacts.
• Responsible for assessing the potential impact from notifiable avian diseases to public health.
• Responsible for coordinating scientific advice and data requirements for species conservation.
• Scottish Ministers have overall responsibility for and oversight of the outbreak response. The relevant Minister will be involved in decision making, working closely with the Chief Veterinary Officer (CVO) Scotland.

Animal and Plant Health Agency (APHA)

• Field delivery of animal health services in Scotland is currently undertaken by the Animal and Plant Health Agency (APHA), who work on behalf of the Scottish Government, the Welsh Government and Defra (UK Government). APHA, on behalf of Scottish Ministers, are the lead operational partner responsible for:
• identifying and delivering responses to notifiable endemic and exotic diseases in animals, and aspects of surveillance for new and emerging pests and diseases;
• scientific research in areas such as bacterial, viral, prion and parasitic diseases and vaccines. They act as an international reference laboratory for many farm animal diseases;
• facilitating international trade in animals and products of animal origin (PoAO); and
• regulating the safe disposal of animal by-products, for businesses, to reduce the risk of potentially dangerous substances entering the food chain.

Animal Disease Policy Group (ADPG)    

• A permanent UK-wide policy forum, which provides disease control advice (e.g. the level and method of surveillance required in dead wild birds) and strategy recommendations to Ministers and other strategic decision makers. Drawing in particular on advice from relevant experts, it reviews and challenges strategic assumptions. ADPG also has an important role in ensuring that policies are coordinated (although they may be different) across the four UK administrations. Membership of ADPG includes representatives from the Scottish Government, Defra, the Welsh Government, DAERA (Northern Ireland), and all four UK CVOs.

Ornithological Experts Panel (OEP)

• This group of ornithological experts, chaired by APHA, provides specific technical and scientific advice and recommendations to supporting Scottish Government and other GB administrations’ policies in response to controlling and preventing outbreaks of avian influenza.

NatureScot (NS)

• Scotland’s statutory nature agency, providing advice on the conservation impacts on key species, coordination of intelligence on the scale of impact on wild birds, regulating certain activities (e.g., taking, killing of species), provision of advice to reserve managers and wider land managers.
• The Scientific Advisory Committee subgroup on Avian Influenza, which sat within NatureScot provided scientific advice to the NatureScot Board and guides practical policy decisions.

Avian Flu in Wild Birds - Scottish Task Force     

• A network across key public and private bodies in Scotland to ensure an efficient, effective and coordinated approach to understanding and mitigating the impact of HPAI in wild birds.
• Provides technical and advisory expertise.
• Membership includes Government and NGOs across animal and public health and welfare, wildlife policy, ornithology.
• Meets frequently at the start of an outbreak.  Currently exists as a correspondence group ready to reconvene as and when required.
• Previous meeting updates can be found here.

Scottish Environment Protection Agency (SEPA)          

• Scotland’s principal environmental regulatory body, with a specific HPAI focus on providing expertise and advice with respect to the disposal of waste materials.

Public Health Scotland (PHS)

• Lead for the public health response in Scotland, responsible for determining and mitigating the risk to public health from HPAI.

Local Authorities (LA)

• Ensure that environmental, health and safety issues are managed during the Scottish response to the HPAI response and responsible for Notifiable Avian Disease legislation enforcement.

Scottish Society for the Prevention of Cruelty to Animals (SSPCA)

• Ensure animal welfare practices are applied in relation to sick wild birds that are reported by the general public.