Appeal for information as police reveal last known position of rare bird of prey missing in Norfolk

Satellite tagging a Montagu's Harrier (Image: Archant)

Scientists working on a project to track bird of prey migration routes tagged three Montagu's harriers, the UK's rarest breeding bird of prey, including this adult female in Norfolk in July.

The tiny satellite trackers, fitted to the harriers' backs, reveal the migration routes the birds take between Europe and their wintering grounds in Africa.

The missing Montagu's harrier, a three-year-old bird nicknamed 'Mo', was last detected leaving a roost site at first light close to Great Bircham, Norfolk, on August 8.

The last signal from Mo's tag came through at 12.30am on that Friday morning, which put the bird roosting overnight in Bircham Common, south of Great Bircham village.

Satellite tagging a Montagu's Harrier (Image: Archant)

The tag should have submitted a further signal at 6.30am, however this signal was never received.

Norfolk Constabulary has launched an investigation into the bird's disappearance.

Inspector Jon Papworth, wildlife officer for Norfolk Constabulary, said: 'The tracking device that was fitted to Mo is extremely accurate and it is highly unlikely to have simply stopped working. Even if the bird had died or been injured the device would still continue to transmit.'

'The tag signal stopped between 5.04am and 6.30am on Friday, August 8, which would have been daylight and when Mo would have been coming out of her roost.

'We are keen to find out what has happened to this rare bird and would ask anyone with information about this bird's disappearance to come forward.'

The Montagu's harrier is a slim, long-winged bird of prey, similar to a hen harrier. The male is pale grey with black wingtips and the female is dark brown. As an extremely rare breeding bird in the UK it needs special protection, and nesting sites are kept secret to prevent theft by egg collectors or general disturbance.

Ben Koks of the Dutch Montagu's Harrier Foundation, who fitted the tag, said: 'Since 2005 we have tagged 58 Montagu's harriers, and a sudden loss of signal is exceedingly rare. It is very unusual that an experienced bird like this would abruptly disappear, especially whilst the tag was in the process of sending data, as it had done successfully for the previous few weeks.'

Mark Thomas, an RSPB senior investigations officer, said: 'There are very few possible reasons for Mo's disappearance, either she was caught by a fox and the tag was immediately taken underground, or she suffered illegal persecution and her tag was deliberately destroyed.

'With only seven pairs in the UK the loss of a breeding female is a serious setback to this threatened bird of prey.'

Naturalist and The One Show presenter Mike Dilger filmed Mo being fitted with a tag earlier in the year and it was shown on the BBC One Show last night (Tuesday).

He said: 'It's a very sad situation. I personally helped to tag Mo: she was a beautiful, healthy harrier and by now she should be zipping through the skies of Senegal. This is a tragic loss of an amazing, and rare bird.'

The tag fitted to this bird was sponsored by the owner of Lush Cosmetics, Mark Constantine, who named the harrier after his wife Mo. He has offered a reward of £5,000 for information on the missing harrier. The two other birds tagged, Madge and Mark, have begun their migration and are currently nearing their wintering grounds in Senegal.

• Anyone with information is asked to contact Inspector Jon Papworth at Norfolk Constabulary on 101 or alternatively call Crimestoppers anonymously on 0800 555 111.

• Anyone interested in following the movements of the other tagged Montagu's harriers can see the birds' journey unfold at www.rspb.org.uk/montytracking or by following the Twitter handle @UKmontagus