Between 1990 and 2010 North West Norfolk Ringing Group had metal ringed 213 Marsh Harrier nestlings only 7 were ever recovered, all were found dead.
According to the British Trust for Ornithology (BTO) between 1909 – 2012 a total of 2569 Marsh Harriers were ringed with metal rings, few were ever reported and most of these were recoveries of dead birds.

The wing tagging project began in 2011 and by the end of 2022 a total of 786 nestling Marsh Harriers had been ringed and wing tagged plus 5 adults. This has resulted in a recovery/sighting rate of 38.18% a result that could not have been anticipated. 

Individuals that have been marked in this project have been reported and photographed all over the UK. Many have involved multiple sightings of the same bird providing a fascinating snapshot of their ‘life’ history so far.  Many of these birds that have been tagged in this project have been seen abroad in Belgium, Portugal, Germany, The Netherlands, Spain and Norway and the first confirmed sighting of a British ringed Marsh Harrier in Senegal and another in the Canary Isles.
Conventional metal ringing alone would never have produced such extraordinary results.