Rapid risk assessment on incursion of HPAI H5N8 into housed or not housed poultry flocks and captive

29 January 2021

Situation as at 26 January 2021

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Contents

Summary ...... 4 Introduction ...... 6 Hazard Identification ...... 10 Previous outbreaks of HPAI H5N8: ...... 12 Current Situation ...... 12 Risk Question ...... 16 Risk Levels ...... 16 Entry Assessment ...... 16 Exposure Assessment...... 22 Domestic poultry ...... 24 Captive birds ...... 25 Ratites ...... 25 birds ...... 26 Consequence assessment ...... 26 Conclusions ...... 28 Assumptions and Uncertainties ...... 30 References ...... 30 Annex 1 ...... 32 Annex 2 ...... 42 Annex 3 ...... 43 Annex 4 ...... 46

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Summary

This is an update of a rapid risk assessment undertaken on 26 November 2020 in response to findings of HPAI H5N8 in poultry (on 02 November 2020) and wild birds (09 November 2020). Since then, there have been further findings of HPAI H5N8 in poultry, captive birds and wild birds in the UK, HPAI H5N1 in one backyard flock as well as HPAI H5N1, H5N2 and H5N5 in wild birds. All updates made on 26 January 2021 are shown in red for ease of reference.

1. In October 2020 the risk of AI H5N8 incursion through migratory wild waterfowl was increased to MEDIUM on the basis of outbreaks in north-west .

2. The report of HPAI H5N8 in a broiler-breeder rearing unit flock in Cheshire (AIV 2020/02) on Monday 2 November was the first confirmed event of HPAI H5N8 in GB since 2017. Two wild geese tested positive for HPAI H5N8 in south-west England on 3 November 2020. The risk of AI H5N8 incursion through movements of migratory wild waterfowl was increased to HIGH on 6 November 2020 and then to VERY HIGH in early December.

3. To 26 January, HPAI H5N8 has been detected at 12 poultry premises in England with three outbreaks in captive birds; 1 poultry premises in Scotland; 2 poultry premises in Northern , with one outbreak of HPAI H5N1 confirmed in poultry in England. To 26 January 2021 the last infected premises detected in GB was in Devon, SW England, on 29 December 2020, while that in Northern Ireland in County Antrim was detected on 11 January 2021. Wales reported an outbreak of HPAI H5N8 on 27 January 2021 at a game rearing establishment.

4. There have been numerous reports of HPAI H5N8 in a range of wild species, including migratory birds, resident birds and bridging species (including gulls and a few corvids, namely Eurasian magpies) in Europe and UK. The arrival of wild waterfowl to overwinter in the UK has by and large ended, and numbers are expected to have peaked in December and January, depending on the species and also the weather conditions in Continental Europe. Large populations of migratory water fowl are still present in the UK. These birds will remain here till March/April and will start departing in numbers from early/mid-March.

5. As of 26 January 2021 there were 299 wild bird positive findings of H5 in England, Wales, and Scotland across 41 counties, and 25 different species. Of there, 274 tested were subtyped as H5N8, 10 H5N1, 6 H5N5 and 9 H5Nx. The total number of positive wild birds detected in addition to the detection of multiple H5 HPAI subtypes in the same epidemic event is unparalleled in the UK.

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6. As a result of the ongoing infection pressure, the risk of AI H5N8 incursion in wild birds is maintained at VERY HIGH.

7. There has been a pattern of spread consistent with previous disease epidemics in which wild bird transmission was a primary factor. There is substantive evidence that spread of H5 HPAI to GB by migrating wild waterfowl has happened on numerous occasions since 2006.

8. Given the large poultry population and the proportion which are outdoor and in regions close to large aggregations of wild waterfowl, we consider the risk of exposure of poultry across the whole GB sill to be MEDIUM (where stringent biosecurity is applied) and still to be HIGH (where biosecurity is sub-optimal). An Avian Influenza Prevention Zone (AIPZ) is in place, and personnel should be taking additional biosecurity measures.

9. Housing free range poultry could reduce the likelihood of infection incursion, by reducing both the direct/indirect contact of free range poultry with wild waterfowl and contact with the contamination in the environment. An EFSA analysis of the 2016/2017 HPAI H5N8 epidemic concluded that housing birds gave a two-fold reduction in risk of virus incursion into poultry houses. However, other measures were equally or more effective (preventing wild bird contact and improving biosecurity measures and education).

10. However, to be effective, housing must be accompanied by thorough biosecurity measures to prevent the disease from being introduced to the poultry through contaminated fomites (e.g. human behaviours affecting spread) or by other items that are taken into or enter the housing. Under some circumstances, it will not be possible to house poultry, captive birds and breeding game birds, whether for practical or welfare reasons relating to their husbandry needs, and so housing will not be universally achieved.

11. An AIPZ was declared in England, Wales and Scotland with additional housing measures that came into force from 14 December 2020. This means all bird keepers in GB (whether they have pet birds, commercial flocks or just a few birds in a backyard flock) are required by law to take a range of biosecurity precautions, including housing their birds (except in very specific circumstances). Any legal requirements to house and take biosecurity measures should be kept under review and adapted as needed to reflect emerging evidence, including levels of compliance with housing and biosecurity measures and the disease picture across Europe.

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Introduction

Across Northern Europe and Russia, and the Middle East since September 2020, HPAI H5N8 infection has been detected in multiple species of wild bird, sometimes prior to the detection of the same virus in various types of domestic poultry. The OIE Reference Laboratory at Weybridge has confirmed this strain is different to the HPAI H5N8 virus circulating in East Europe earlier this year and different to the virus circulating in 2016/2017.

Outbreaks and cases (wild birds) reported in the lead up to the first reports of HPAI H5N8 in the UK on 09 November 2020 are shown in Table 1. In early November a rapid risk assessment was undertaken to address the risk of incursion of H5N8 HPAI into housed and non-housed birds (domestic poultry and captive birds) from contact with migratory wild waterfowl from Europe during the 2020/2021 winter season. This was reviewed on 26 November 2020.

Since then, there have been further findings of HPAI H5N8 in poultry, captive birds and wild birds in the UK, HPAI H5N1 in one backyard flock as well as HPAI H5N1, H5N2 and H5N5 in wild birds.

Table 1: Outbreaks and cases of HPAI H5N8 in Central Asia, Middle East and Europe to early November 2020. Date Country Details

August Central Russia, Kazakhstan Multiple poultry farms and wild bird cases

September Russia (Caspian Sea); Multiple poultry farms and wild bird Kazakhstan, cases

10/10/2020 Russia (West near Belarus) Poultry – 28,000

16/10/2020 EU (Netherlands) Eurasian (live)

Two migration pathways contribute to infected wild waterfowl flying out of central Russia/Kazakhstan. The first is the Mediterranean pathway which contributed to reported cases in the Middle East (Israel) as birds fly to Africa in October. European countries along this route would include those in Central and South-eastern Europe. The second is the East Atlantic route which contributed to cases in the North European countries, particularly Scandinavia, Germany, Denmark, Poland, Ireland and GB. There are not clear boundaries between these migration routes and the birds will have mixed between them to some degree on the

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breeding grounds. Multiple waterfowl species may be found at the same breeding ground sites and at the same wintering sites. The numbers of HPAI H5Nx cases in wild birds and captive birds reported in Europe in the week commencing 19 January 2021 are presented in Table 2.

Table 2: Current outbreaks of HPAI H5Nx in domestic poultry and captive birds and cases in wild birds (from 19 to 26 January 2021), according to official reporting sources. Note that this is a rapidly changing picture and new disease reports are being made as we draft this risk assessment. (Annex 3 lists the wild bird species involved in these reports).

H5 H5N3 H5N5 H5N8

Country Total Wild/Captive Wild/Captive Wild/Captive Wild/Captive Poultry Poultry Birds Birds Birds Birds

Belgium 1 1

Czech 1 1 Republic

Denmark 1 15 16

Finland 1 1

France 102 1 103

Germany 2 5 3 3 13

Ireland 1 3 4

Italy 1 1

Norway 3 3

Poland 2 1 3

Romania 2 2

Spain 1 1

Sweden 1 2 3

Ukraine 1 1

Total 3 3 1 6 108 32 153

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An Avian Influenza Prevention Zone (AIPZ) has been declared in England, Scotland and Wales (effective from 5pm on the 11 November 2020) with additional housing measures in force from 14 December 2020. This means all bird keepers (whether they have pet birds, commercial flocks or just a few birds in a backyard flock) are required by law to take a range of biosecurity precautions, including housing their birds (except in very specific circumstances). Elsewhere, a housing order has been put in place in the Netherlands, southern Norway and in the north German state of Schleswig-Holstein. In the epizootic of 2016/2017, many EU MSs put in place a housing order. The orders may cover just certain sectors of commercial poultry and certain high risk areas.

The effectiveness of a housing order is difficult to assess. In 2016/2017 it is possible there would have been a higher number of outbreaks without an order in place; however, in France, Germany and Hungary, countries with the highest number of outbreaks and with housing orders in place, there was secondary spread, indicating poor biosecurity in some sectors, rather than primary contact with wild birds per se. The EU has recently warned that secondary spread between establishments keeping anseriforme species is observed (PAFF, 2020, and communication from Cion).

EFSA carried out a comprehensive review of the outbreaks of HPAI H5N8 in 2016/17 to assess the risk of introduction into poultry from migratory and residential wild birds (EFSA, 2017). The opinion concluded that once virus is introduced to a wild bird population, a critical population size is required before virus amplification and further wild bird-associated geographical spread of the virus can take place. Therefore, there is an increased likelihood of incursion into poultry farms most closely located to large gatherings of wild birds (including but not exclusively waterfowl) of target species1 during the migration season. Once the migratory birds leave (from March onwards usually) the risk of incursion usually reduces but in cases in which non-migratory birds are still testing positive, there will be a continual, albeit lower, risk.

The opinion also concluded that the relative risk reduction for entry is three fold by preventing access to water bodies, that housing gives a further two fold reduction, and by applying routine biosecurity there is a further four fold reduction in risk while high biosecurity is a 44 fold reduction in risk.

The opinion recommends that the following biosecurity measures for housed birds which should be applied are: separating from wild birds; separate waterfowl from gallinaceous poultry; provide potable drinking water; implement a hygiene lock for

1 The list of target species is available in Annex II Part 2 of Commission Decision 2010/367/EU on the implementation by Member States of surveillance programmes for avian influenza in poultry and wild birds.

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each poultry house and provide biosecurity training to all personnel. For non-housed birds, it was recommended to restrict access to birds for people and provide biosecurity training to personnel as the most feasible and sustainable measures. At all times, feed must be provided indoors only, wild bird access should be restricted; and contacts with other poultry premises limited. Feed and water could be provided under a roof or a horizontal fabric for non-housed birds. The opinion used expert knowledge elicitation to gather evidence on the biosecurity measures and a lack of biosecurity awareness in the staff on sites was commonly reported.

A further supporting document to EFSA opinions on the risk of introduction of HPAI into poultry farms in general (EFSA, 2017a) was a systematic review of previous outbreaks to identify risk factors and concluded that the main risk factor for introduction is contact with wild birds or fomites contaminated with wild bird faeces. Other important risk factors were poultry species (waterfowl and turkeys are higher risk); production system, where outdoor systems are higher risk than indoor; and presence of biosecurity flaws.

This rapid risk assessment is aimed at providing advice around the most appropriate form of prevention zone order for the different sectors and establishing whether there is evidence to help make decisions around mandatory housing. Any prevention order would only be put in place in an area not already under restriction for a notifiable avian disease.

Under article 6(1) of the Avian Influenza and Influenza of Avian Origin in Mammals (England) (No 2) Order 2006 (“the Order”), the Avian Influenza and Influenza of Avian Origin in Mammals (Scotland) Order 2006 and the Avian Influenza and Influenza of Avian Origin in Mammals (Wales) (No 2) Order 2006, the Secretary of State must carry out a risk assessment in order the declare an Avian Influenza Prevention Zone.

Measures to reduce the risk of transmission of avian influenza 6.—(1) If, after carrying out a risk assessment, the Secretary of State considers such action necessary to reduce the risk of transmission of avian influenza to poultry or other captive birds from wild birds or from any other source, he must— (a) declare an avian influenza prevention zone in all or part of England/Scotland/Wales; or (b) serve or require an inspector to serve a notice on the occupier of any premises where poultry, other captive birds or any categories of poultry or captive birds specified in the notice are kept. (2) A declaration or notice under paragraph (1) must impose such measures as the Secretary of State considers necessary to reduce the risk of transmission of avian influenza. (3) When deciding the measures to impose under paragraph (2), the Secretary of State must consider whether measures are necessary—

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(i) to prevent direct or indirect contact which wild birds might otherwise have with poultry and other captive birds; (ii) to reduce the risk of feed and water provided to poultry and other captive birds being contaminated with avian influenza virus; and (iii) to reduce the risk of the spread of avian influenza between premises. (4) The power of the Secretary of State to impose measures by declaration or notice under this article includes the power— (a) to require poultry and other captive birds to be housed or otherwise kept separate from wild birds; (b) to require poultry or other captive birds or categories of such birds specified in the declaration or notice to be housed or otherwise kept separate from other poultry and captive birds; (c) to require that poultry and other captive birds are provided with feed and water to which wild birds have no access; (d) to require keepers of poultry and other captive birds and others who come into contact with such birds to cleanse and disinfect their footwear and take such other biosecurity measures as a veterinary inspector or an inspector under the direction of a veterinary inspector may require; (e) to ban or limit the collection of poultry or other captive birds at any fair, market, show, exhibition, race or other gathering; (f) to ban or limit the use of birds of the orders (including , geese and swans) and Charadriiformes (including gulls, murres, terns, avocets, puffins, woodcock, oystercatchers, sandpipers, plovers, surfbirds, snipes and skimmers) as decoys during bird hunting.

Hazard Identification

The hazard identified is the avian influenza virus, predominantly H5N8 HPAI subtype but other virus subtypes have been detected including H5N1, H5N2, H5N3 and H5N5.

Virus has been isolated from outbreaks and wild birds in the EU during the current epizootic, and the World Health Organisation (OIE) and Food and Agriculture Organisation (FAO) International Reference Laboratory (IRL) for Avian Influenza (AI) at the Animal and Health Agency (APHA) has undertaken sequence analysis. Diagnostic evaluation utilised frontline molecular assays and whole genome sequencing techniques to define the genetic composition of the causative agent. Importantly, despite various virus subtypes and genotypes, the haemagglutinin gene is highly conserved (amongst these strains to date in the 2020/21 epidemic) and this

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factor critically underpins fundamental virus properties such as infectivity and transmissibility.

The virus from the GB outbreaks maps across the whole genome with the H5N8 viruses (reported by the lab as part of an international collaboration) found elsewhere in Europe (multiple countries), Middle East and Central Asia (including Russian Federation and Kazakhstan) during the last 6 months (and therefore distinct from the strain that caused widespread outbreaks in the EU in the first part of this year).

Topology of the phylogenetic tree for the HA gene indicates that all UK report case isolates detected during Autumn/Winter 2020/2021 (including 17 H5N8 and 1 H5N1) cluster within clade 2.3.4.4b alongside all European isolates for which sequence is available. These viruses also cluster with H5N8, H5N5 and H5N1 HPAI viruses from the across the EU, and Russia, again within clade 2.3.4.4b. Interestingly, the H5N1 viruses cluster together whilst the H5N5 and H5N8 viruses appear to be more closely related with H5N5 viruses sitting at different points within the main Autumn/Winter 2020 cluster. All Autumn/Winter 2020 detected viruses cluster together within clade 2.3.4.4B, but separately from the H5N8 viruses responsible for the outbreaks in Europe in late 2019- early 2020. Specifically, the HA gene appears to descend from the HPAI H5N8 viruses which caused the previous epidemic wave that caused outbreaks across the Eurasian and African continent in 2016-2017, and is highly related to the H5N8 viruses which have been circulating in Egypt since 2017 with the closest genetic linkage being an isolate detected in Iraq in May 2020.

On the other hand, the three H5N1 viruses are almost identical and result from multiple reassortment events with LPAI viruses circulating in wild birds in Eurasia, from which they have acquired six (PB2, PB1, PA, NP, NA and NS) out of eight (6/8) gene segments. Whether this reassortment event has occurred in Europe or Asia is an issue that cannot be assessed from the data available to date.

Wild bird cases in England, Wales, and Scotland have tested positive for HPAI H5N1, H5N2, H5N5, and H5N8. The detection of four H5 HPAI subtypes in the same epidemic event is unparalleled in the UK or indeed at European level. All these viruses are genetically closely related through their haemagglutinin gene, which is the key viral gene influencing pathogenesis, host range, transmission, and host immunity. Continued virus change by genetic reassortment in wild birds is not unexpected, and further genetic variation at genome level may be expected as the epidemic progresses.

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Previous outbreaks of HPAI H5N8:

In 2014/2015 several outbreaks of H5N8 HPAI were detected in poultry in Europe (Germany, Italy, Netherlands and GB) all in housed birds and were attributed to indirect contact with infected wild waterfowl. In the Netherlands, there were four separate incursions and two were linked premises. In Germany, there were just two separate introductions and, in both Italy and GB (England), only single premises were affected. No direct links were found between the different countries. Wild waterfowl testing positive for H5N8 HPAI were only detected in Netherlands and Germany, in and teal, after the outbreaks had been notified. No significant wild bird mortality was observed in 2014/2015.

In the HPAI H5N8 2016/2017 epizootic, virus spread rapidly in migratory and non- migratory wild waterfowl in Europe causing mortalities in these birds. This was strikingly different to previous years and indicated a change in the virus pathogenicity for certain species of bird. By the end of the season most EU countries, as well as Europe, the Middle East and parts of southern and west Africa had reported cases of this virus. Current Situation

This year to date, there is a lack of evidence for whether some species of wild waterfowl do not show clinical signs on infection with this virus strain and whether the virus can continue to circulate in non-migratory, sedentary birds. However, considering the number of birds found dead in non-breeding sites across Europe (in the hundreds) compared to the total number of birds in these sites (likely to be in the many thousands), it is feasible that the virus is circulating widely with low mortality (see Map 1).

This pattern of geographical distribution follows that seen for the epizootic of H5N1 HPAI in 2005/2008 in Europe, and in H5N8 HPAI in 2016/2017 in Europe. In those years, spread occurred along a similar route of migratory wild waterfowl causing wild bird die-offs in North and Central Europe (see maps 2 and 3).

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Map 1: Current outbreaks and wild bird cases of H5N8 HPAI (as of 26 January 2021).

Map 2: Outbreaks and wild bird cases of HPAI H5N8 in Europe in 2016-2017

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Map 3: Outbreaks and wild bird cases of H5N1 HPAI in Europe, North Africa and the Middle East in 2005-2008

Therefore, this new epizootic is following a similar pattern of transmission in wild birds and spill-over into domestic poultry as observed with HPAI H5N8 in 2016-2017, and H5N1 HPAI in 2005 – 2008 and it can be expected that the current H5N8 HPAI epizootic will continue to cause issues with the poultry sector for several months to come, if not for many months, if the virus continues to circulate in migratory and then in non-migratory waterfowl in Europe.

There are three emerging trends apparent in Continental Europe. The first trend of note is that the rate of new wild bird case reports has fallen, and the total number of wild bird cases has levelled off in December although may be slightly increasing again in the last month. Thus, each European country only reported a handful of wild birds cases in the week beginning 19 January 2021 (Table 2). To 26 January 2021, this year there have been 93 wild bird cases of 844 in total since October; of which 38 were reported to OIE on 22 January. At this stage in the 2016/17 epizootic there had been 625 wild bird cases, with cases rising to over 1,000 by mid-February 2017 in the second peak. There is, however, a suggestion of a second rise in wild bird cases in early January this year; but it is too early to tell if this is a true second peak, as was observed at the end of January 2017 in the 2016/17 H5N8 epizootic. ADNS (data to 17/1/21) for EU MSs, plotted weekly by the EU Ref laboratory (IZSVe, 2021), show wild bird cases dropping off to very low numbers at the end of 2020 compared to the peak of ~150 per week in November 2020.

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However, the second week of January saw this jump to ~35 wild bird cases per week falling to ~18 in the third week. Care needs to be taken in interpretation of wild bird data in relation to the risk to poultry because surveillance activity may have reduced in some countries over Christmas period. Wild bird cases and submissions appear to be reducing in the UK, with associated lower infection pressure, but there will be a lag effect with virus in the environment as the virus decays after wild bird amplification. Although we have seen a definite reduction in the rate of new cases in the UK, this cannot be solely attributed to the decrease in wild bird cases in Continental Europe. The reduction in new cases in wild birds in the UK will ultimately translate into lowering the infection pressure in the environment. The trends in wild birds in both Europe and the UK are in a positive direction given normal infection dynamics in wild birds.

The second trend in Europe is that overall the number of outbreaks reported in poultry after appearing to increase slightly, particularly in Germany and Poland, is now reducing. The exception is France, which has reported a large increase in numbers as H5N8 spreads though the industry in the south-west (Table 2). The situation in south-west France should not be used as an indicator for the UK because it is not due to primary cases from wild birds, but due to secondary spread in a challenging sector.

The third development is that outbreaks are now being reported in south-east Europe, with Hungary, Slovakia and Romania now reporting HPAI. Until recently, this epizootic has mainly been an outbreak of north-western Europe, although Italy and Slovenia have been affected. This represents diffusion of the virus over a wider area as local populations of wild birds become infected through localised movements.

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Risk Question

What is the risk of incursion of H5N8 HPAI into housed and non-housed birds (domestic poultry and captive birds) from contact with migratory wild waterfowl from Europe during the 2020/2021 winter season?

Risk Levels For the purpose of this risk assessment, the following EFSA-derived definitions will be used:

Negligible So rare that it does not merit to be considered

Very low Very rare but cannot be excluded

Low Rare but does occur

Medium Occurs regularly

High Occurs very often

Very high Events occur almost certainly

Entry Assessment

The wild waterfowl population in GB is relatively well understood. Several NGOs conduct regular surveys for the wild waterfowl at known wintering and breeding sites across GB. In particular, the British Trust for Ornithology (BTO), The Joint Nature Conservation Councils (JNCC), the Royal Society for the Protection of Birds (RSPB) and the Wildfowl and Trust (WWT) carry out counts of wild birds. Their evidence shows the sites of the largest waterbird aggregations in GB (see Figure 1). The Wash is one of the premier sites for wintering waterbirds in GB with over 300,000 birds counted each year, while other top ten sites include the Somerset levels, the Dee estuary, the Humber estuary and the Ribble, Alt and Mersey estuaries, but there is a variation of at least 10% from one year to the next, attributed to the winter weather conditions. There are 53 sites with at least 20,000 birds wintering year after year across GB.

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Figure 1. Wild bird assemblage abundance in GB, derived from 109 species considered most relevant for the transmission of AI to poultry flocks. (From Hill et al. (2019) Scientific Reports 9:19973)

In terms of migration, the wild waterfowl will have been arriving in GB from Northern Europe since August / September and numbers generally peak in December to January. While some species, such as swans, will be site loyal from one year to the next, others will be less so, and there will be mixing between species in the large aggregation sites. Outward migration will start again in March to May.

Expert opinion from the JNCC and BTO suggests that Eurasian wigeon, a species of migratory duck, are most abundant in Netherlands and GB with some testing positive for HPAI H5N8 in Germany, the Netherlands and the UK. Wigeon start arriving in the UK from September with numbers building through October to December.

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Furthermore cases of live trapped or positive shot wild birds in Netherlands and Italy suggests that “healthy” wild birds are carrying infection.

Figure 2. The combination of wild bird assemblages and poultry density as a risk map, which informs the poultry survey, targeting the high risk areas.

See Annex 2 for estimated numbers of wild birds entering GB in comparison to the Netherlands and Italy in any year (Flutest project 2014). It can be seen from these data that for most migratory species, fewer birds arrive here than to the Netherlands in any one year; nevertheless, there are still significant numbers. Although these data are some years old, at present, we are seeing a usual seasonal flow of

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migratory birds, and this is not currently affected by any cold weather conditions in Europe.

The frequency of peak occurrence of waterbird species by month and by county are available on the Bird Survey website http://app.bto.org/webs-reporting/. For example, the monthly frequency of the common teal and the Eurasian wigeon (the two highest risk species according to Flutest) are shown here, based on the 2018/19 survey:

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Given the daily reports of HPAI H5N8 in wild birds in Belgium, Denmark, Germany, Ireland, Italy and Netherlands that were seen in October/November, the increasing numbers of wild birds being found dead in Europe and the total populations involved, and, more recently, the cases in Sweden, Norway, Romania, Hungary, Slovakia and Slovenia, it is likely that there are still birds which are not showing clinical signs and are able to migrate to the UK, although at this stage in late January this is less likely. There is evidence that sedentary birds present in GB have been infected may still be infectious with ongoing transmission and a source of virus circulation in other birds within GB.

There is a system for wild bird surveillance in GB, whereby found dead birds from target species are reported either by wardens at reserves and wetland sites, or by the public for testing at the NRL. As of 26 January 2021, there were 299 wild bird positive findings of H5 in England, Wales, and Scotland across 41 counties, and 25 different species. 274 tested were subtyped as H5N8, 10 H5N1, 6 H5N5 and 9 H5Nx. The total number of positive wild birds detected, in addition to the detection of multiple H5 HPAI subtypes in the same epidemic event, is unparalleled in the UK. HPAI H5N8 virus has been identified in a range of wild bird species, with mute swans, greylag geese and Canada geese representing the majority of detections. This is in contrast to 2016, when initial detections were found primarily in tufted ducks, swans and gulls.

The Barnacle geese over-wintering in the Netherlands are different populations from the GB populations, and probably come through the Baltic from Norway/western , while the Barnacle geese that winter in Scotland either come from (via ) or from Svalbard (via north Norway). There, avian influenza is rarely detected and represent a different migration flyway. In autumn, Greylag geese mainly move south from Scandinavia, or in southern GB are resident bird populations. Eurasian wigeon are migratory ducks from breeding areas in northern Russia and Eastern Europe.

Although there is considerable uncertainty around the transmission of HPAI H5N8 from migratory to local sedentary species, HPAI H5N8-positive findings in GB are in both migratory birds and resident birds (, Canada geese, mute swans) suggesting that significant local transmission of virus is occurring. These are detailed in Annex 4.

A qualitative estimate of the numbers of migrating higher risk species of waterbirds arriving in GB from various areas of Europe, Asia and Africa in autumn/winter is shown in Table 3 by species (Gale et al. 2014).

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However, the key message is that these birds have now arrived in the UK in these numbers and we are now detecting both further spread within these populations wintering within the UK and also increasingly spill-over event to our indigenous sedentary populations as shown in Annex 4. Thus, the dynamic is shifting which correlates to more sporadic wild bird cases which overall reduces infection pressure in the environment and therefore reducing risk to poultry. In summary, the indigenous birds provide an ongoing background risk after multiple primary introductions via migratory waterfowl.

Table 3. Qualitative estimation of number of higher risk species of waterbirds migrating from different regions of the world to GB, the Netherlands and Italy (per year) (n). This is based on numbers of birds in Annex 2. Negligible numbers are excluded (Gale et al. 2014) Species Western Eastern Asia West East and Europe Europe Africa Southern Africa Bewick’s swan L L VL Whooper swan L VL VL Mute swan M VL Greater white-fronted goose VL VL VL VL Red-breasted goose VL Eurasian wigeon H M M L Common teal H L L L M L L VL M L L L VL VL VL VL VL VL L VL L VL L L L VL M L L Black-headed gull H L L Number of individual birds in each qualitative category: >1,000,000 Very high (VH); 100,001 - 1,000,000 High (H); 10,001 – 100,000 Medium (M); 1,001 – 10,000 Low (L); 1 - 1,000 Very Low (VL); 0 Negligible (excluded)

Based on the numbers of wild bird cases in north-western Europe to date this season compared to the 2016/17 outbreak, it is concluded that the wild bird infection pressure is higher and there is evidence that sedentary wild bird species in the UK are now infected (see Annex 4).

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Bridging species include several sedentary indigenous birds, such as gulls and corvids. Many gulls but also a few corvids (namely Eurasian magpies), have tested positive for HPAI H5N8 on the Continent and in the UK. As bridging species, gulls are known to have long daily flight patterns between feeding sites, such as open farmland or rubbish tips, and their night roosts such as reservoirs and gravel pits. They are likely to have a role in fomite transmission from areas where there is environmental contamination. Fomite transmission via multiple pathways is particularly important in the current situation, considering the environment is high risk across the country.

We therefore consider the likelihood of there being infected wild waterfowl present in GB is VERY HIGH as a country-wide assessment. However, there will be regional variation, based on the proximity to aggregation sites for non-breeding wild waterfowl. LOW uncertainty.

Exposure Assessment

There are multiple pathways for the exposure of poultry to notifiable avian diseases (Defra, 2018).

These include:

• Contact with infected poultry such as live birds, hatching eggs and day old chicks of poultry

• Contact with live infected wild birds, particularly waterfowl

• Contact with poultry products and by-products of infected poultry,

• Contact with contaminated feed, water, bedding, equipment, vermin or clothing / footwear of people in contact with infected birds or contaminated environment.

Biosecurity advice which poultry keepers should practise at all times of the year are focussed on these pathways as there is a constant low risk of incursion from any notifiable avian disease being introduced into poultry because LPAI viruses circulate constantly in wild waterfowl. The EFSA report from 2017 used a combination of systematic review of all poultry outbreaks and expert knowledge elicitation from members of the poultry sectors. What was clearly stated in the expert knowledge elicitation was the need to not only implement biosecurity measures which are

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feasible and sustainable but also the importance of training poultry workers in what these measures mean.

Contact with live infected wild birds, particularly waterfowl:

Wild birds will forage for food away from their assemblages and geese in particular may move up to 7km on a daily basis. As more migratory birds arrive and if the weather worsens over winter, they may also move away from the coast and be observed inland. In addition, gulls which can act as a bridging species, fly tens of km a day to feed, returning in the evening to their over-night sites.

Housing birds will reduce direct contact with wild waterfowl. It will not prevent any of the other pathways through which disease may enter a poultry premises. Other biosecurity measures will be more important. The likelihood of contact with wild waterfowl will be dependent on the number of such species in the near environment and how attractive the site is to such birds. The presence within the poultry premises of a or open feed bins are two well-known factors which make direct contact with wild waterfowl more likely for poultry with access to the outside environment.

Expert opinion is that the virus will retain infectivity in the environment at low temperatures, at least to 55 days at 4oC (Ian Brown, APHA, Pers. Comm.). This means the environment could remain contaminated for several weeks or more. Preliminary APHA data indicate that the current H5N8 HPAI virus could have extended survival properties, compared to the 2016 H5N8 virus, but further work is ongoing.

As the most likely contact of poultry kept outdoors with wild waterfowl will be in those areas where there are high concentrations of these species, the likelihood of direct contact with wild waterfowl or indirect contact with their faeces would be greater for those poultry establishments in close proximity to, or with sites attractive to, wild waterfowl. Therefore, where there are no large aggregations of wild waterfowl, the risk is lower for this particular pathway, but there are still other pathways which could lead to the introduction of any notifiable avian disease. It is worth reiterating that H7 LPAI viruses which circulate in wild waterfowl, when introduced into housed layer hens, have been known to mutate into HPAI which is a more disruptive infection to control, due to the increased size in control zones.

Although in the 2016/2017 season, the (few) outbreaks in commercial poultry establishments in GB were all housed birds, since not all poultry premises throughout GB were tested, it is not possible to say whether outdoor flocks were exposed and did not exhibit clinical signs.

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Incursion through imported live or products:

For the other pathways, contact with other live birds (i.e. trade in poultry, hatching eggs, day old chicks) will be dependent on the business itself and the commercial activities. Contact with products or by-products from infected birds will be dependent on the activities of people entering the premises and bringing such products with them and it should be noted that swill feeding is not legal. These will not be addressed in detail for this assessment. However, housing birds will not impact on this risk.

Contact with contaminated feed, water, bedding, equipment, vermin or clothing / footwear of people in contact with infected birds or contaminated environment:

Contamination of feed, bedding and water by wild birds can be prevented by sourcing such products from safe sources and keeping such items in containers which no wild birds can access. The site can be made less attractive to wild waterfowl by preventing access to any on site or excluding ponds and pools of standing water from the range and making sure feeding areas are protected. Contact with contaminated equipment, footwear and clothing can be prevented by making sure all personnel in contact with the birds use disinfectants appropriately. This will be particularly important where birds are housed, as contact with the birds is more frequent, as feed, bedding and water must be brought into the houses and birds must be checked for welfare issues or eggs collected from inside the houses. Visitors to the farm should also be recorded for security and to help tracing exercises. Other biosecurity practices should be employed to ensure wild birds are separated from flocks such as feeding birds indoors or under cover, discouraging wild birds from landing, removing wild bird contamination and draining watercourses, removing feeders and water stations from the range, ensuring good building maintenance and regular inspections for signs of wild bird/rodent access. Vermin control is strongly recommended because rodents act as fomite spreaders.

Above all, the EFSA opinion recommended ensuring all personnel are trained in, and practise, good biosecurity, regardless of whether birds are housed or not.

Domestic poultry

The GB poultry sector is complex and seasonally variable. There is a requirement for all poultry keepers in England, Scotland and Wales with more than 50 birds to be registered with the British Poultry Register. For fewer than 50 birds it is voluntary. Therefore, any data available will not necessarily include the backyard or smallholder community. In comparison to data available in 2013, the outdoor chicken sector has decreased from 62% of total holdings to 30% in 2018.

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The poultry sector can be designated in the following way with the various populations according to the 2018 poultry register:

As proportion As proportion of Number of Number of Poultry Type of total total poultry Birds holdings population holdings Total Chickens 270986618 85.45% 10125 51.98% Outdoor 33500062 10.56% 5879 30.18% Chickens Layers 47186064 14.88% 5454 28.00% Broilers 166134899 52.39% 1663 8.54% Total Turkeys 8462070 2.67% 1069 5.49% Outdoor 1642191 0.52% 443 2.27% turkeys Total ducks 4108083 1.30% 1364 7.00% Outdoor ducks 981325 0.31% 878 4.51% Total geese 146332 0.05% 187 0.96% Outdoor geese 116826 0.04% 125 0.64% Total CDGT 283703103 89.46% 12745 65.43% Total Pheasant 23918729 7.54% 4733 24.30% Total Partridge 9512172 3.00% 2001 10.27% Total Poultry 317134004 19479

Note: the “outdoor” label is only an estimate and the NCP Salmonella survey estimates the free range population to be 55% of the layer birds and 18% of turkeys.

Captive birds

Captive birds, such as those held in collections, zoos or approved bodies are already semi-housed and should be kept separate from wild waterfowl. For some, this will be difficult to prevent access to their water environment (penguins, pelicans, flamingos etc), but it is unlikely it will be possible to house indoors, so every effort should be made to prevent wild waterfowl access. There were outbreaks in captive birds in Europe (in zoos) in 2016/2017 and a derogation exists in EU legislation which means birds may not have to be destroyed, unless they are in contact with the infected collection.

Ratites

Ratites, such as ostriches, cannot be housed on a long term basis. Outbreaks of closely related H5N8 HPAIV have been reported in commercial ostriches in South Africa since 2017. Ratites are therefore susceptible to some strains of HPAIV at least

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and there has been a case in Germany of an emu showing clinical signs in a zoo and therefore these birds should also be considered susceptible.

Game birds

The majority of game birds have already been released for the shooting season and therefore are considered wild birds and outside the scope of a prevention order around housing. Some will still be kept in pens and could not be housed due to welfare issues, therefore the pens themselves would need to be netted where possible to ensure the birds cannot escape and forage locally. Game bird keepers should use the guidance https://www.gfa.org.uk/user_files/uploads/Bird_Flu_and_Gamebirds.pdf

Captive birds used as decoys would be at risk of increased contact with wild waterfowl. If they remain at one place for the duration of the fowling season, then they will not come into contact with domestic poultry; however, if the birds are moved around to other sites or spend any time at a premises where domestic poultry are kept, this is an increased risk for the poultry. It is illegal to release by hand captive birds for the purpose of being shot immediately after their liberation, under Part 1, Section 8 of the Wildlife and Countryside Act, 1981.

Given the large poultry population and the proportion which are outdoor and in the regions close to the large aggregations of wild waterfowl, we consider the risk of exposure of poultry across the whole GB still to be MEDIUM (where stringent biosecurity is applied) to HIGH (where there are biosecurity breaches) (LOW uncertainty). Twenty infected premises have been identified across England, Scotland, Northern Ireland and, most recently, an infected premises with game birds in Wales. Furthermore, HPAI H5N8 (and other subtype combinations) has been confirmed in many wild birds in England, Scotland, Wales and Northern Ireland. However, it is important to emphasise both the role of wild ducks and geese visiting poultry premises, and the bridging species flying over or visiting sites. An AIPZ is in place, and personnel should be taking additional biosecurity measures. The pathways which lead to disease incursion are not prevented by housing per se, but housing birds is a risk reduction measure.

Consequence assessment

Any outbreak of notifiable avian disease has a significant impact on GB poultry industry, through the trade and economic impacts on the producer and the sector. This is the same for any notifiable avian influenza virus. Average costs to government may be between £2 and £4 million per outbreak, depending on the

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number of birds involved and time taken to complete secondary C&D and return to disease free status.

Housing birds which are not used to housing can cause welfare issues. Making sure their environment is enriched (e.g. with toys), that they have plenty of room to move, access to feed and water, clean bedding and the ability to display natural behaviours are all welfare priorities. For ducks, their bedding must be changed regularly as they will mess it quickly and they need access to water so they can clean their feathers. If the birds become stressed, they may be more prone to infections or other behaviours which impact on welfare. Certain species cannot be housed for welfare reasons or because they are already considered wild: geese, ratites and gamebirds.

GB is required to deliver surveillance for H5 and H7 LPAI incursions in poultry (including H5 and H7 HPAI in Anseriformes) under Council Directive 2005/94/EC and Commission Decision 2010/367/EU. An option for Risk Based Surveillance is available and has been applied in GB since 2012. The output of the model used for the risk based targeting of surveillance in poultry identified 2231 10km grid squares where wild waterfowl and registered poultry flocks are co-located as identified from 2016 “Sam” (APHA’s registration database) and British Trust for Ornithology data. For these grid squares, a risk score >0 could be assigned and then ranked into 6 bands of equal numbers of grid squares (approximately 373 in each rank) – where Rank 1 represents the lowest and rank 6 the highest risk. The remaining areas of GB where no poultry premises were registered have been assigned a “zero risk” score even though non-commercial poultry may be resident and wild waterfowl abundant. The actual risk of AI incursion therefore will not be “zero” in these areas.

The area of any prevention order which included housing could be done under a Ministerial Order, at a national, regional or county level or at a smaller area level. In terms of delineating these areas, the interactive map available at https://defra.maps.arcgis.com/apps/webappviewer/index.html?id=8cb1883eda5547c 6b91b5d5e6aeba90d uses the risk-based poultry survey model, which already takes into account the areas of high wild waterfowl populations (Figure 1) and a “foraging distance” for waterfowl. Consideration should also be paid to the different poultry populations which could be housed without compromising welfare. A national order or even a regional order would be of significant consequence to the poultry sector where the risk reduction is not considered to be significant. That consequence is around the possible increase in risk of the other pathways which could bring avian disease into contact with the poultry, through increasing the level of contact with workers and increasing transmissibility of viruses between the birds when they are in close contact with one another. This could also increase the risk of mutation of LPAI viruses into HPAI viruses as seen with previous outbreaks in Europe for H7 viruses.

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Options for the area of any prevention order are therefore considered as follows: Sector National Regional County level Small 10/10 km2 zones Chickens Not Not Possible and easiest Preferred but Turkeys considered considered to mandate but not all difficult to Ducks appropriate appropriate premises at same risk operate based on the based on the level Geese variable risk variable risk Not considered Not considered Gamebirds level for any level for any appropriate for these appropriate for Ratites species species species these species Captive birds Recommendation around separation of birds and preventing wild waterfowl access

Conclusions

Housing should only be applied in conjunction with other biosecurity measures, but it should be noted that it will not be effective if used as a single measure. The trigger for such an order should be associated with a primary case in wild waterfowl or high confidence that a poultry outbreak is related to contact with wild birds. In the current outbreak, there have been twelve outbreaks of HPAI H5N8 in poultry confirmed on premises in England, and one outbreak confirmed on a premises in Scotland. There have also been three cases of HPAI H5N8 in captive birds in England, and one case of H5N1 in backyard chickens, in England. In addition, there have been two outbreaks in poultry confirmed in Northern Ireland. On 27 January H5N8 was confirmed at a game rearing establishment near Amlwch, Isle of Anglesey, Wales.

Housing should only be applicable to those species where the welfare of the birds is not compromised.

In GB the sensitivity of our wild bird avian influenza surveillance has been increased to ensure collection and analyses of any number of targeted species of wild birds (essentially ducks, geese, swans, gulls and birds of prey) known to carry risk of infection with AI viruses. Single dead birds of target species where possible will be collected and tested.

At this stage at the end of January few migrating waterfowl are expected to enter the UK from Europe even if the weather were to deteriorate significantly in the coming weeks. Even if a few more birds did fly over, this would not necessarily increase the estimated risk areas alluded to in this document, given the VERY HIGH level already

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assessed for wild birds. The migration season for wild waterfowl to overwinter in the UK has by and large ended, and numbers are expected to have peaked in December and January, depending on the species and the weather conditions in Continental Europe. A large population of migratory water fowl are still present, however, and will not be leaving the UK until March/April. Furthermore, there is evidence of spread to sedentary birds in the UK.

If the HPAI H5N8 virus circulates in native sedentary wild waterfowl and becomes established, as happened with HPAI H5N1 in 2005-2008, then housing could not be applied for such a long period. In the current demographic, sedentary species are now largely those testing positive. The survival of the virus in the environment during winter means the risk will not decrease for a period of weeks at the earliest. The higher survival rate of the virus in the environment during winter means the risk of environmental transmission remains, and hence, the continued risk of secondary spread into indigenous UK wild bird species and naïve non-indigenous. Higher environmental temperatures, together with increasing sunlight intensities will reduce environmental levels of H5N8 and the associated risks.

As discussed above, a second peak occurred at this time of year in the 2016/17 H5N8 epizootic. Monitoring weekly changes over the next few weeks is therefore important with regard to trends (up or down) in infection risk based upon number of poultry incursions and level of detections in wild birds both in the UK and on the continent.

If the risk has not changed and no new outbreaks or cases have been detected in GB, despite passive surveillance and testing of wild birds found dead, the prevention order should be reviewed after the peak migratory wild waterfowl occurrence is past, i.e. at end of January. However, an outbreak of HPAI H5N8 was confirmed in GB on 28 January 2021.

The following conditions could be used to inform when the risk levels will be reduced. Firstly, the time of year and if our migrant non-breeding waterfowl have left GB; secondly if time has lapsed since the last reported case and there is a significant reduction in infection pressure from the Continent; thirdly if the temperature has started to increase with higher sunlight levels, then the environmental contamination and transmission would be reduced. These could form part of the “exit strategy” although other factors including the uncertainties listed below need to be considered.

As the housing order has been applied, an exit strategy is now required and this should also be based both on a risk assessment and other epidemic considerations. However, an expectation of no wild bird cases could be disproportionate i.e. one case per week when surveillance sensitivity has been maximised will not correlate

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with a very high wild bird risk. The housing order was introduced on the basis of numerous wild bird cases and several poultry outbreaks and the same criteria in reverse could be used as an exit strategy in addition to using the three scientific conditions above to inform the risk assessment. Assumptions and Uncertainties • The wild bird counts for this year are not known and we are using an annual assessment based on previous years.

• Other wild waterfowl species (although this assessment considers the most abundant) may also be important for the transmission of this virus.

• The patterns of movement of gulls are more complex than waterfowl. They prefer to roost around land tips and reservoirs, therefore these should not be ignored as potential sites of concern for proximity to poultry farms.

• The evidence for the economic benefits and dis-benefits of housing birds is not part of this assessment.

• The 2016/2017 epidemic allowed experts to analyse the likely risk factors leading to an incursion of avian influenza and while housing birds was assessed as giving a twofold reduction, other factors such as preventing access to wild birds (three fold) and improving biosecurity (four fold) are also significant.

• While housing may prevent direct contact with wild waterfowl, it could increase indirect contact with contaminated environment and the birds may be under stress, leading to more disease transmission and greater likelihood of viral mutation. Regular contact with wild birds and their LPAI viruses may produce an environmental “vaccine” protection against HPAI viruses.

References

Defra (2018) https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_da ta/file/759784/ai-rationale-hras-nov2018.pdf

EFSA (2017) J.efsa.2017.4991

EFSA (2017a) So.efsa.2017.EN-1282

Gale, P. et al. (2014) entry of H5N1 highly pathogenic avian influenza virus into Europe through migratory wild birds: A qualitative release assessment at the species level. Journal of Applied Microbiology 116, 1405-1417.

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PAFF (2020) https://ec.europa.eu/food/sites/food/files/animals/docs/reg- com_ahw_20201020_pres_hpai_efsa.pdf

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Annex 1

Data on migratory waterfowl in Scotland Wintering sites in Origin HPAI priority Scotland for Scotland

Bewick’s Swan Does not tend to winter Western Siberia Very low in Scotland. Previously flew through Scotland from Netherlands to Ireland, but less so now

Whooper Swan Caerlaverock, grazes Iceland Very low* in fields so could contact poultry

Mute Swan Generally sedentary Very low

Greylag Goose Wintering flocks in Non-resident UK Very low Scotland, but sites in Greylags originate extreme north and from Iceland. north-west of Scotland Wintering populations are occupied by a in northern Germany, resident population. Denmark, Greylags feed Netherlands more exclusively on likely to fly to England agricultural land and in cold weather could contact poultry

Barnacle Goose Winter in Caerlaverock South-west Solway Low (Solway )and also west wintering populations coast and islands are from Spitzbergen, while north-west are from Greenland

Pink-footed Goose Grazes in fields so breeding grounds in Very low could contact poultry, Spitsbergen, Iceland Loch of Strathbeg and Greenland. UK (Aberdeenshire) is birds are from wintering site for 20% Greenland, Iceland. of world population. Winters around east coast, central belt and Solway (Caerlaverock)

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Wintering sites in Origin HPAI priority Scotland for Scotland

Bean Goose Rare in UK in general, Northern Eurasia, Very low site in south-west Siberia, also eastern Scotland population wintering in south-

Greenland white- West coast of Scotland Greenland Very low fronted goose (flavirostris)

Eurasian white- Rare in Scotland Northern Russia and Very low fronted goose eastern population (albifrons) wintering in South- east Asia

Lesser white-fronted Very rare vagrant Very low Goose

Light-bellied brent East Scotland, Solway, Spitzbergen Very low goose (hrota) central belt

Light-bellied brent West coast (and Greenland Very low goose (hrota) Ireland)

Dark-bellied brent Common in southern Northern Russia and Very low Goose (bernicla) England, but not in eastern population Scotland wintering in South- east Asia

Red-breasted Goose Very rare vagrant Very low

Eider Large wintering Low population in Scotland, all round coast, albeit with 8 sites with counts exceeding 1,500 birds. Although, highly gregarious, not likely to come in contact with poultry as sea duck rarely found away from coast due to dependence on mussels. Very rare

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Wintering sites in Origin HPAI priority Scotland for Scotland

inland, no need for freshwater

Goosander Largely freshwater catches salmon and trout, unlikely to come in contact with poultry

Goldeneye Diving duck, unlikely to Birds from northern Very low come in contact with Europe winter in poultry Scotland

Eurasian Wigeon Grazes on grass, so Some breed in Medium opportunity to come in Scotland, many from contact with poultry. Eurasia Although an estuarine bird, loss of eelgrass has resulted in switch to inland grass in flooded marshy areas. Largest wintering sites in England not Scotland

Common Teal Could come in contact Wintering population Medium with poultry. England drawn from complete has largest numbers breeding range – with Loch Leven Iceland, northern having smaller Europe, the Baltic numbers States, and a large area of the Russian Federation.

Northern Pintail

Mallard Main sites are in Medium England but widely distributed. Could come into contact with poultry

Gadwall

Tufted Duck Diving duck, unlikely to Large wintering Low come in contact with population in GB

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Wintering sites in Origin HPAI priority Scotland for Scotland

poultry. British generally from breeding birds eastern parts of generally sedentary European range during winter. Main site in Scotland is Loch Leven.

Pochard Diving duck, unlikely to Wintering birds Low come in contact with originate mainly from poultry. Low site fidelity Baltic (62% from suggest highly mobile. Latvia) and Russia Loch Leven is principal site from end of June

Greater Scaup Main sites are Solway Icelandic birds winter Low Firth, Loch Ryan, in north-western Morray and the Scotland, those on Islands. Diving ducks east coast from feed on mussels, Fennoscandian and mainly coastal in Russian populations winter, unlikely to contact poultry

References

Owen, M. (1980) Wild geese of the World. Batsford

Ogilvie, M.A. (1978) Wild geese. T&AD Poyser

Cramp, S. (1977) Handbook of the Birds of Eurpe the Middle East and North Africa. The birds of the Western Palearctic. Volume 1, Ostrich to ducks.

35

Data on migratory waterfowl in England/Wales

The focus is on those birds coming to England/Wales via the Baltic coast

Species Wintering sites in Origin HPAI priority for England England/Wales

Bewick’s Swan Some 9,000 birds Single population for Medium – winter in Britain north-western Siberia because of small (mainly England numbers which including south-east always fly England and central through the Baltic England) and Ireland

Whooper Swan 16,000 birds in Britain Mainly from Iceland. Very low – and Ireland, mainly Very few of the because not from Scotland. Some sites Russian and Fenno- Baltic in eastern, northern Scandinavian England such as breeding population Welney WWT in come as far as Norfolk. England even in cold weather, normally winter in the Baltic

Mute Swan Generally sedentary Very low because in Britain, Ireland and does not migrate importantly in the Low from Low Countries Countries, hence Mute Swan cases in NL are not a concern

Graylag Goose Wintering flocks in Non-resident UK Very low Scotland, but sites in Greylags originate extreme north and from Iceland. north-west of Scotland Wintering populations are occupied by a in northern Germany, resident population. Denmark, Greylags feed Netherlands more exclusively on likely to fly to England agricultural land and in cold weather could contact poultry

Barnacle Goose Mainly winter in Wintering populations Very low Scotland and northern are from Spitzbergen, Ireland. Wild birds are while north-west are rare in England, from Greenland. A

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Species Wintering sites in Origin HPAI priority for England England/Wales

although there are small number of feral flocks Russian birds which winter in the Netherlands could come over to south- east England in severe weather.

Pink-footed Goose Grazes in fields so UK birds are from Low risk due to could contact poultry. Greenland, Iceland small numbers Mainly East Anglia while Spitzbergen coming from and Lancashire. breeding population Denmark, winters in Denmark, Germany in West Germany and severe winters, the Low countries, presumably with a few reaching south-east or Britain in severe east coast of winters. England.

Bean Goose Rare in UK in general, Northern Eurasia, Very low because small numbers Siberia, Finland of low numbers in wintering at sites in 100,000 pairs breed England. East Anglia but not in western Siberia many

Greenland white- Rare winter visitors to Greenland Negligible fronted goose England, a few winter (flavirostris) in Wales

Eurasian white- Baltic-North Sea Breeds in northern Medium, comes fronted goose group winters in the Russia, Novoya through the Baltic (albifrons) Netherlands, Belgium, Zemlya and Kanin to England each England and Wales. In Peninsula year but not a England winters in the common bird. selected sites in the south (Severn Estuary, Kent, East Anglia)

Lesser white-fronted Very rare vagrant, one North Scandinavia, Negligible Goose or two birds in western Siberia England each year, most winter in the Balkans

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Species Wintering sites in Origin HPAI priority for England England/Wales

Light-bellied brent Very small numbers in Spitzbergen and Negligible goose (hrota) England/Wales, more Greenland in Ireland

Dark-bellied brent Common in coastal Northern Russia and Medium risk of Goose (bernicla) sites and marshes in eastern population H5N8 entry and southern England. Not wintering in South- highly gregarious, common inland or on east Asia but unlikely to . contact poultry because coastal.

Red-breasted Very rare vagrant Very low Goose

Shelduck Many resident in Breeding population Medium risk of England but some returns back from entry of H5N8 but migrate to moult in moult migration to generally tidal mud flats in north breeding range in coastal/estuarine Germany in July Britain bird. October/November

Eider Winter around south Relatively small Very low and east coast of movements, rarely England although less over 200 km. common than in Scotland. Although, highly gregarious, not likely to come in contact with poultry as sea duck rarely found away from coast due to dependence on mussels. Very rare inland, no need for freshwater

Goosander Largely freshwater Males summer moult Very low catches salmon and in north Scandinavia. trout, unlikely to come Breeders in Russia in contact with poultry. and Fenno- Winters in sites across Scandinavia migrate UK although west to Baltic and uncommon and many yeyond to

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Species Wintering sites in Origin HPAI priority for England England/Wales

from breeding sites in Netherlands and Scotland. Britain.

Goldeneye Diving duck, unlikely Birds from northern Low to come in contact Europe, Russia winter with poultry with in the Baltic, wintering sites across Denmark, England. Netherlands and Britain.

Eurasian Wigeon Grazes on grass, so Some 200,000 pairs High opportunity to come in breed in western contact with poultry. Russia and 80,000 Although an estuarine pairs in Finland. bird, loss of eelgrass Migrate through the has resulted in switch Baltic to winter in west to inland grass in and south-west flooded marshy areas. Europe including Bird is gregarious with Germany, large wintering sites Netherlands, France, across much of central Britain and Ireland. England.

Common Teal Graze on grass and Breeding birds from High could come in contact north Russia, with poultry. England Scandinavia, Baltic has large numbers States, north Poland, with wintering sites north Germany and across England. Bird Denmark fly south- is gregarious. west in the autumn to wintering grounds in the Netherlands and Britain. Winter distribution between Netherlands, England, Wales and Ireland greatly dependent on weather; cold spells cause immediate westward movement.

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Species Wintering sites in Origin HPAI priority for England England/Wales

Northern Pintail Scattered sites across Icelandic birds winter Low due to England. in Britain (no risk) but smaller numbers some from north-west than other ducks Russian, Finland and Baltic States fly west to winter in Netherlands and Britain, with movement from the Netherlands to Britain in hard weather.

Mallard Many are resident in Icelandic birds winter Medium but UK. Many sites are in in Britain (no risk) but reduce to low England and widely some from north-west because bird is distributed. Could Russian, Finland, not gregarious come into contact with Baltic States and poultry northern Germany fly west to winter from Denmark to north France and in Britain.

Gadwall Many resident in Breeders in Germany, Medium England and also Poland, and west wintering sites mainly central Russia winter in England. in the Netherlands and Britain.

Shoveler Many wintering sites Breeders from Fenno- Medium because across England. Filter Scandinavia and although water- feeder so restricted to Russia migrate west feeder could water unlikely to feed and south-west to infect other in fields. Bird is Netherlands, Britain gregarious gregarious. and Ireland. waterfowl species which feed in fields.

Tufted Duck Diving duck, unlikely Large wintering Medium risk of to come in contact population in GB entry because with poultry although generally from although diving highly gregarious. eastern parts of duck could infect British breeding birds European range, other gregarious generally sedentary waterfowl species during winter, and

40

Species Wintering sites in Origin HPAI priority for England England/Wales

many wintering sites Russia and which feed in across England. Scandinavia. fields.

Pochard Resident population Wintering birds Medium risk of but also many originate mainly from entry because wintering sites across Baltic (62% from although diving England and Wales. Latvia) and Russia duck could infect Diving duck, unlikely other gregarious to come in contact waterfowl species with poultry but highly which feed in gregarious and may fields.. infected other species. Low site fidelity suggest highly mobile.

Greater Scaup Mainly marine with a Birds on east coast of Low because few coming to inlake England from although highly lakes. Diving ducks Fennoscandian and gregarious less feed on mussels, Russian populations likely to contact mainly coastal in freshwater ducks. winter, unlikely to contact poultry

References

Owen, M. (1980) Wild geese of the World. Batsford

Ogilvie, M.A. (1978) Wild geese. T&AD Poyser

Cramp, S. (1977) Handbook of the Birds of Eurpe the Middle East and North Africa. The birds of the Western Palearctic. Volume 1, Ostrich to ducks.

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Annex 2

Numbers of migratory birds (per year) entering GB, the Netherlands and Italy calculated as the difference between totals of monthly counts (maximum - minimum), taken from Flutest project work underpinning Gale et al. (2014). HRS Bird Species GB, Wetland The Netherlands Italy, peak national Bird Survey (Hustings et al. count in January data of Austin 2008) between 1990 and et al. 2008 2005. Atkinson et al. (2006) Bewick’s Swan Cygnus 3,775 13,000 0 columbianus Whooper Swan Cygnus 7,428 2,000 0 cygnus Mute Swan Cygnus olor 11,542 5,000 3,248 Greater White-fronted 1,341 600,000 11,049 Goose (European race) Anser albifrons albifrons Greylag Goose Anser 72,980 150,000 5,392 anser Red-breasted Goose 4 7 4 Branta ruficollis Eurasian Wigeon 324,097 600,000 123,936 penelope Common Teal Anas 126,498 50,000 97,529 crecca Mallard Anas 97,872 180,000 208,000 platyrhynchos Northern Pintail Anas 25,344 20,000 12,781 acuta Garganey Anas 38 (May) + 47 80 (Apr) + 110 223 querquedula (Aug)* (Aug)* Northern Shoveler Anas 11,200 10,000 22,811 clypeata Common Pochard 24,160 45,000 42,189 Aythya ferina Tufted Duck Aythya 46,429 150,000 7,725 fuligula Black-headed Gull 150,555 150,000 217,468 Larus ridibundus *Spring and autumn migration

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Annex 3

Species list for cases in wild birds (as of 7 am on 25/01/2021), according to OIE. Country Wild bird species affected Belgium (Branta canadensis) (Columba palumbus) Egyptian Goose (Alopochen aegyptiaca) Eurasian Curlew (Numenius arquata) Eurasian Magpie (Pica pica) European Herring Gull (Larus argentatus) Great Crested Grebe (Podiceps cristatus) Greater White-fronted Goose (Anser albifrons) Greylag Goose (Anser anser) Mute Swan (Cygnus olor) Pink-footed Goose (Anser brachyrhynchus) Czech Republic Mute Swan (Cygnus olor) Denmark Barnacle Goose (Branta leucopsis) Black-headed Gull (Chroicocephalus ridibundus) Brant Goose (Branta bernicla) Common Buzzard (Buteo buteo) Common Eider (Somateria mollissima) (Phasianus colchicus) Eurasian Curlew (Numenius arquata) Eurasian Sparrowhawk (Accipiter nisus) European Herring Gull (Larus argentatus) Gadwall ( strepera) Greater White-fronted Goose (Anser albifrons) Greylag Goose (Anser anser) Mallard (Anas platyrhynchos) Mute Swan (Cygnus olor) Northern Gannet (Morus bassanus) Northern Goshawk (Accipiter gentilis) Peregrine Falcon (Falco peregrinus) Pink-footed Goose (Anser brachyrhynchus) Bean Goose (Anser fabalis) White-tailed Eagle (Haliaeetus albicilla) Whooper Swan (Cygnus cygnus) Finland Common Pheasant (Phasianus colchicus) France Black-headed Gull (Chroicocephalus ridibundus) Brant Goose (Branta bernicla) Common Buzzard (Buteo buteo)

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Country Wild bird species affected Common Shelduck (Tadorna tadorna) European Herring Gull (Larus argentatus) Greylag Goose (Anser anser) Mute Swan (Cygnus olor) Red Knot (Calidris canutus) Germany Accipitridae (unidentified) (Accipitridae (incognita)) (unidentified) (Anatidae (incognita)) Anserinae (unidentified) (Anserinae (incognita)) Ardeidae (unidentified) (Ardeidae (incognita)) Charadriidae (unidentified) (Charadriidae (incognita)) Common Buzzard (Buteo buteo) Crane (unidentified) (Grus (incognita)) Gull (unidentified) (Larus (incognita)) Haematopodidae (unidentified) (Haematopodidae (incognita)) Laniidae (unidentified) (Laniidae (incognita)) Passeridae (unidentified) (Passeridae (incognita)) Rallidae (unidentified) (Rallidae (incognita)) Strigidae (unidentified) (Strigidae (incognita)) Swan (unidentified) (Cygnus (incognita)) Hungary Great Egret (Ardea alba) Ireland Barnacle Goose (Branta leucopsis) Charadriidae (unidentified) (Charadriidae (incognita)) Eurasian Curlew (Numenius arquata) Mute Swan (Cygnus olor) Peregrine Falcon (Falco peregrinus) Whooper Swan (Cygnus cygnus) Italy Common Buzzard (Buteo buteo) (Anas crecca) Eurasian Wigeon (Mareca penelope) Greater White-fronted Goose (Anser albifrons) Greylag Goose (Anser anser) Lithuania Mute Swan (Cygnus olor) Netherlands Barnacle Goose (Branta leucopsis) Charadriidae (unidentified) (Charadriidae (incognita)) Common Buzzard (Buteo buteo) Eurasian Teal (Anas crecca) Eurasian Wigeon (Mareca penelope) Greater White-fronted Goose (Anser albifrons) Greylag Goose (Anser anser) Indian Peafowl (Pavo cristatus) Mallard (Anas platyrhynchos) Muscovy Duck (Cairina moschata)

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Country Wild bird species affected Mute Swan (Cygnus olor) Phasianidae (unidentified) (Phasianidae (incognita)) Short-eared Owl (Asio flammeus) Taiga Bean Goose (Anser fabalis) Norway Barnacle Goose (Branta leucopsis) Eurasian Wigeon (Mareca penelope) European Herring Gull (Larus argentatus) Great Black-backed Gull (Larus marinus) Mew Gull (Larus canus) Mute Swan (Cygnus olor) Pink-footed Goose (Anser brachyrhynchus) Poland Greylag Goose (Anser anser) Mute Swan (Cygnus olor) Taiga Bean Goose (Anser fabalis) Whooper Swan (Cygnus cygnus) Romania Whooper Swan (Cygnus cygnus) Russia Anatidae (unidentified) (Anatidae (incognita)) Common Pochard (Aythya ferina) Mallard (Anas platyrhynchos) Mute Swan (Cygnus olor) Tufted Duck (Aythya fuligula) Slovakia Muscovy Duck (Cairina moschata) Mute Swan (Cygnus olor) Mute Swan (Cygnus olor) Spain Greylag Goose (Anser anser) Peregrine Falcon (Falco peregrinus) Sweden Barnacle Goose (Branta leucopsis) Eurasian Eagle-Owl (Bubo bubo) Peregrine Falcon (Falco peregrinus)

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Annex 4

UK wild bird detections by species indicting whether populations are largely sedentary or migratory Grand Status Country / species H5N1 H5N5 H5N8 H5Nx Total

England 7 1 254 7 269

Black Swan 11 11 Sedentary

Brent Goose 6 6 Migrant

Common buzzard 1 4 1 6 Sedentary

Canada Goose 1 24 25 Sedentary

Great White Egret 1 1 Sedentary

Grey Heron 1 1 Sedentary

Greylag goose 8 2 10 Sedentary

Herring Gull 2 2 Sedentary

Kestrel 1 1 Sedentary

Lesser Black Backed Gull 1 1 Sedentary

Black headed Gull 1 1 Sedentary

Mixed Avian 1 1

Mute Swan 5 1 153 1 160 Sedentary

Peregrine Falcon 1 1 Sedentary

Pink footed goose 2 2 Migratory

Partial migrant Shelduck 1 1 but mainly

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Grand Status Country / species H5N1 H5N5 H5N8 H5Nx Total

sedentary at this time of year

Sparrow Hawk 1 1 Sedentary

Unspecified 1 1

Unspecified Goose 1 1

Unspecified Swan 11 11

Whooper Swan 21 2 23 Migratory

Wigeon 1 1 Migratory

Red Kite 1 1 Sedentary

Wales 5 1 6

Little Grebe 1 1 Sedentary

Mute Swan 5 5 Sedentary

Scotland 15 2 17

Greylag goose 1 1 Migratory

Mute Swan 5 5 Sedentary

Unspecified Swan 4 4

Whooper Swan 4 4 Migratory

Red Knot 1 2 3 Migratory

Grand Total 7 6 270 9 292

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