Avian influenza (Bird flu): GB surveys of wild bird populations to screen for the presence of Avian Influenza

Surveillance overview

Surveillance for avian influenza viruses in domestic poultry and wild birds is part of a European initiative and is carried out in all European Member States.

The UK strategy for avian influenza surveillance includes:

The GB wild bird survey for avian influenza viruses

There are a number of ways in which highly pathogenic avian influenza (HPAI) H5N1 viruses may be spread, including the movement of infected poultry and poultry products and the movement of contaminated vehicles, clothes, objects and utensils. It is thought that wild birds have the potential to play a role in the spread of HPAI H5N1 to domestic poultry. The wild bird survey provides an early warning if highly pathogenic avian influenza H5N1 viruses are introduced into GB in wild birds and an assessment of the risk of introduction into domestic poultry.

There are an extremely large number of wild birds in GB so it is therefore only practical to sample a small percentage of these.  Certain species of wild birds that experts believe to have a greater potential role in the spread of avian influenza viruses (e.g. gulls, ducks, geese, swans and waders) are central to the Survey.

It is normal for a proportion of wild birds to carry low pathogenic avian influenza viruses so it would not be unusual to detect some LPAI viruses over the course of the survey. These are normally of little significance to human or animal health.

The likelihood of a wild bird that is found dead being infected with avian influenza is very small.  Dead wild birds are screened because they are a convenient source for sampling and not because their death is likely to be due to avian influenza.  If the virus is found, there are powers under the Animal Health Act 1981 which allow us to kill wild birds, but there is no intention to use these powers at present.  The control of avian influenza infection in wild bird populations is not feasible - from a logistical, environmental and biodiversity point of view. Indiscriminate culling of wild migratory bird populations would be ineffective in preventing further spread of avian influenza and their hunting would likely cause dispersion of the birds.

During 2007 HPAI H5N1 was detected in a number of wild birds in several European countries.

The GB Wild Bird Survey 2008-09

As a result of increased scientific knowledge and practical experience in handling incidents of avian influenza the GB strategy for 2008-09 will change from October 2008.

The Survey focuses on the patrolling of designated reserves by skilled wild bird ecologists and wardens.  This is active all year round and provides enhanced screening and assessment of dead wild birds suitable for testing.

Members of the public do not need to report the finding of small numbers of dead wild birds but are asked to remain vigilant for incidents where 10 birds or more are found dead in the same location and at the same time (a 'mass mortality event'). There are separate arrangements for mass mortality events in Scotland where findings of 5 dead birds or more are to be reported.

If you find a mass mortality event please follow the available guidance.

A Wild bird surveillance priority counties map is available.

    • Sampling of live caught wild birds
    • Screening of wild birds found dead at wetland sites
    1. Survey of live caught birds to identify the presence of avian influenza virus:

    Samples are collected from the live caught birds, at several wetland sites throughout the UK. Birds are caught, ringed and sampled. The birds are released and samples are screened for avian influenza viruses.

    2. Screening of wild birds found dead in wetland reserves
    Selected reserves across GB will be patrolled on a regular basis by skilled wild bird ecologists and wardens.  These patrols will be active all year round.  Dead wild birds belonging to certain species will be submitted for avian influenza virus screening. The frequency of patrols and number of patrolled sites may be increased in an area where there is a known increased risk of HPAI occurrence.

    Public reporting

    Members of the public in GB are no longer asked to report the finding of small numbers of dead wild birds but are asked to remain vigilant for incidents where 10 birds or more are found dead in the same location and at the same time (a 'mass mortality event'). There are separate arrangements for mass mortality events in Scotland where findings of 5 dead birds or more are to be reported.

    In Northern Ireland public reporting is still requested - reports are directed to the DARD helpline (Tel. 028905 24999).

    The investigation of mass mortality events in wild birds

    This is separate survey to establish the causes of deaths of large numbers of birds (die offs). It has been running for several years now and was established before the avian influenza survey.  Die offs may be the result of poisoning, adverse weather conditions, starvation or one of a number of infectious diseases. They are unlikely to be the result of avian influenza, although, amongst other things, samples are screened for avian influenza viruses.

    As part of routine wildlife disease surveillance we will be undertaking post mortem examination of birds in incidents where 10 birds are found dead in the same location and at the same time. This is called a 'mass mortality event'. There are separate arrangements for mass mortality events in Scotland where findings of 5 dead birds or more are to be reported.

    Inside the avian influenza surveillance areasthese incidents should be reported to the Defra helpline. If the location is outside the surveillance areas, members of the public may report the situation directly to the regional VLA laboratory (or SAC in Scotland) who will decide if the deaths should be investigated further (the helpline can advise on the local regional laboratory and the contact number).

    Further information on wildlife disease surveillance is available here.

    Defra Helpline 08459 33 55 77, 8.00am to 6.00pm Monday to Friday.

    In Northern Ireland, reports are directed to the DARD helpline (Tel. 028905 24999) where an initial assessment is made. If the die off is suspicious, the caller is referred to DARD’s Veterinary Service where a further assessment is made.

    Further information

    Page last modified: 5 December, 2008