Study follows marsh harrier migration

Wing tagged marsh harrier. Photo by Andy ThompsonNews update from the Hawk and Owl Trust

Five young marsh harriers hatched on Sculthorpe Moor Reserve in Norfolk, UK have had wing tags fitted as part of a long-term study to see where the species travels to once the young birds leave the area where they were hatched.

This year’s birds join a total of 27 young marsh harriers hatched from other Norfolk sites in the same season and 14 from the 2011 generation, making a total to date of 46 birds carrying distinctive lime green wing tags.

Hawk and Owl Trust marsh harrier tag. www.hawkandowl.orgTags are visible to the naked eye from a distance, and the individual codes can be read with binoculars or telescopes.

Older birds can be distinguished from this year’s because the 2011 harriers’ tags carried white letters and numbers, while the 2012 birds have black codes.

The fitting of the wing tags is done by bird ringers, who have a wealth of experience and knowledge in handling birds of all species. It is a painless experience for the birds. Data 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 stayed within the UK and Channel Islands.

This study will allow the scientists to understand the following questions:

1. Where do these birds go once they are independent of their parents? Are they a long distant migrant, travelling into Europe and beyond, or do they stay in the local area for the winter?
2. Once mature, do they return to the area where they were hatched, or do they breed at completely different sites?
3. Once they start to breed, do they breed in their traditional reed bed habitat or in other crops?”

None of Jersey’s marsh harriers have been given wing tags but several have been given numbered metal leg rings in common with other bird species ringed locally and elsewhere.

Please report any sightings of wing-tagged harriers if they come to Jersey or pass through the Island. Sightings should be reported to the Hawk and Owl Trust here but please also let the Société Jersiaise Ornithology Section know too. All records are valuable even if details of the wing codes are not clear to the observer. Look out too for any birds with coloured plastic leg rings that might be obvious – these might be birds from other study programmes.


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