Press Releases - November/December 2007
Item 4

No. 2007/11/82
November 2007

Tracking wild bird movements

In the light of the recent outbreak of Avian Influenza in Suffolk, British Trust for Ornithology scientists will be talking about how information collected by volunteer bird ringers is used to map the movements of birds across Europe in ‘More or Less’ on BBC Radio 4 this afternoon at 4.30 pm (19 November). BTO scientists, working closely with Defra, can provide rapid advice about the risks posed by Avian Influenza if the H5N1 virus is released into wild bird populations.

In 2005, when European outbreaks of Avian Influenza (bird flu) occurred first in Russia and then in Turkey, Romania, France and elsewhere, BTO migration experts were called upon to assess the risks of transmission to the UK. It was possible to scan through over 650,000 movements of ringed birds within the BTO’s database and to say how many birds of which species had made journeys to and from affected countries in the past, but it was hard to look at the timing of probable movements. Defra, and in particular its epidemiological expert Professor John Wilesmith, recognised the huge value of the BTO’s datasets but realised that we needed a more streamlined method of analysing and synthesising the data to help them respond to potentially fast-moving events. Funding from Defra has enabled BTO scientists to develop a migration mapping tool which provides a clear picture of the timing of migration and has significantly improved the quality of the advice ministers receive. This work has been expanded across Europe by EURING and Wetlands International, with additional EU funding.
See http://blx1.bto.org/ai-eu/ and Note 1 below.

In a recent article from BTO News (the BTO membership magazine), the authors – Phil Atkinson, Jacquie Clark, Humphrey Crick and Rob Robinson – have used the White-fronted Goose to show how the new ‘migration mapping tool’ works. They have analysed the many hundreds of movements of individual ringed White-fronted Geese into and out of Britain & Ireland to show the direction and timing of migration. If, for instance, there were to be an outbreak of bird flu in Denmark in November then this sort of analysis would provide valuable information to decision-makers in Defra on where they might target their surveillance (i.e. potentially to areas where White-fronted Geese are found in England). Now that the technique has been developed, it can be applied to any species that has been ringed in sufficient numbers.

Dr Humphrey Crick, Senior Populations Ecologist of the BTO said:
“We need to remember that the majority of outbreaks of the highly pathogenic H5N1 strain of avian flu in Asia and Europe over the last three years have not been linked to wild migratory birds. However, given that migratory birds have occasionally been affected, this tool is a significant step forward in helping Defra assess the possibility that an outbreak anywhere in Europe or Scandinavia could be brought to Britain.”

Jacquie Clark, Head of the Ringing Unit at BTO said:
“We were pleased that Defra recognised that we have excellent data about the movements of birds, due to the huge efforts of bird ringers, working as part of the BTO’s Ringing Scheme. We have used this information to develop a ‘migration mapping tool’ to give an easy to understand picture of the timing of migration and the areas from which migratory waterfowl that visit Britain & Ireland originate, or through which they travel. We can now provide much better information to Defra to help them target their surveillance for a potential avian flu incursion.”

Images are available to use alongside this release and a pdf of the article can be obtained from

Please see over for Notes for Editors

Notes for editors

1. The migration mapping tool can be accessed at http://blx1.bto.org/ai-eu/ If, for instance, there were to be an outbreak of Avian Influenza in White-fronted Geese in Denmark in November, we can use the tool to ascertain whether birds from this area are likely to be on their way to the UK.
   • Enter http://blx1.bto.org/ai-eu/
   • Select the country that you are interested in ‘Great Britain & Ireland’ (GB&I)
   • Browse species and select White-fronted Goose
   • Click on top left map to see animation of where ‘our’ White-fronted Geese come from
   • Return to White-fronted Goose page. Flyway of interest is the one from the east so click on left map in second row. The numbers on the map indicate where ‘our’ White-fronts are most likely to be in each month. November is month 11.
   • Return to White-fronted Goose page. Select Denmark to see table of ringing recoveries. There is only one ringed bird that links Denmark and GB&I.
   • Despite there only being one movement of a ringed bird from Denmark there appears to be a chance that White-fronted Geese in Denmark in November may well move to GB&I later in the winter (and expert knowledge would suggest that this is more likely if the weather in Europe becomes particularly cold). Surveillance for AI in wild birds would be focused in areas which hold populations of White-fronted Geese, as well as areas that hold other species that create a link to Denmark.
2. Volunteer ringers give freely of their time and expertise and also provide a substantial part of the funding for the Ringing Scheme. The Scheme is also funded by a partnership of the BTO and the Joint Nature Conservation Committee (JNCC) (on behalf of Natural England, Scottish Natural Heritage and the Countryside Council for Wales, and also on behalf of the Environment and Heritage Service in Northern Ireland). The Scheme also receives support from National Parks and Wildlife (Ireland).
3. On average, fewer than one out of every fifty birds ringed is subsequently reported to the BTO, so every report of a ringed bird is of value. To report a ringed bird, phone 01842 750050, write to Ringing Unit, BTO, The Nunnery, Thetford, Norfolk, IP24 2PU or log on to www.ring.ac
4. Bird photographs are available for use alongside articles. E-mail with your request quoting reference 2007-11-82.
5. The BTO has an ISDN line for radio interviews.

For further information please contact:

Jacquie Clark – 01842 750050, or email: during office hours

Humphrey Crick – 01842 750050, or email: during office hours

Graham Appleton – 01842 750050, 07704 847935 (mob), 01603 758276 (home) or email: anytime