Members of the public are being asked to help a study to monitor the movements of rare Marsh Harriers in Norfolk.

The study began last year and is being carried out by national bird of prey conservation charity the Hawk and Owl Trust.

It intends to discover:

* Where do these birds go once they are independent of their adults? Are they a long distant migrant, travelling into Europe and beyond, or do they stay in the local area for the winter?

* Once mature, do they return to the area where they were hatched, or do they breed at completely different sites?

* Once they start to breed, do they breed in their traditional reed bed habitat or in other crops such as oil seed rape?'

Nigel Middleton, conservation officer for the Hawk and Owl Trust in the Eastern region said: 'Twenty years ago this study would not have been undertaken, no-one would have dreamed of approaching a marsh harrier nest because they were such a rare breeding bird.

'Although they are still very rare birds the numbers of marsh harriers now breeding in Norfolk means we are in a better position to study this bird and have been given permission by Natural England.'

Norfolk by Hawk and Owl Trust volunteer and North West Ringing Group member Phil Littler is working with other Norfolk bird ringers.

The Norfolk birds have a lime green tag and an individual identifying combination of two letters or one letter and one number with one tag per wing. It is a painless experience for the birds.

Last year 14 young Marsh Harriers were tagged. Sightings of four of these birds have been reported.

One was seen on the Isle of Sheppy in Kent last autumn, one spent the winter around Lakenheath Fen and another near Welney. The fourth bird was reported on the Somerset Levels this spring, and possibly the same one crossed the River Severn into south Wales.

This year, 32 birds have been tagged at sites around Norfolk.

Marsh Harriers nest at Sculthorpe Moor Community Nature Reserve, near Fakenham, each year and leave in the autumn.

Cameras installed on nests at the reserve over the last few years have given insight to the private life of young harriers. Data from the footage is being analysed by students at Leicester University but little is known about the birds' movements once they leave the nest, where they go in winter and where they return to nest in the spring.

Marsh Harriers are migratory and are expected to fly south, however in recent years many Marsh Harriers have been seen along the north Norfolk coast and the Norfolk Broads in winter.

Members of the public can help by reporting any sightings of wing-tagged marsh harriers.

If you see a wing-tagged bird, make a note of the letters and numbers on the wing tag – if you can see them, date, time and location (if possible an OS six figure grid reference) and also the sex and age of the bird - if it is possible to tell. Contact the Hawk and Owl Trust at www.hawkandowl.org and complete the electronic from.

The project is being funded through generous donations made by the visitors who attended the 2007 'Wild About the Wensum Event' hosted by the Pensthorpe Conservation Trust, near Fakenham.