The curlew is the largest European wading bird and has a long down-curved bill
A Gloucestershire bird is at the centre of a national project to find out more about the species.
The British Trust for Ornithology (BTO) is tagging the curlew, which occurs on a site of international importance in the county.
A team of BTO ringers have begun catching and ringing the birds, with nearly 70 curlews at Wibdon Warth - on the Severn Estuary between Lydney and Chepstow - already tagged.
The aim of the tagging - which has permission of the landowner and Natural England - is to contribute to the BTO project of monitoring the turnover of waders at sites they regularly use.
It is also hoped that the study will also "provide additional data" for assessing the effect of possible tidal barrages on the Severn.
Gloucestershire Wildlife Trust (GWT) has backed the initiative.
"Curlew occur in Gloucestershire both as a breeding species and a wintering species," said Mike Smart, GWT trustee and international wetland expert.
"In the breeding season, they nest in hay meadows along the Severn and Avon, notably at Gloucestershire Wildlife Trust's nature reserves at Coombe Hill and Ashleworth, where they may be seen from February to July."
Outside the breeding season, the birds can be found on the Severn Estuary with around 3000 visible during the peak month of September.
All the birds were marked with a combination of colour rings.
It is hoped that local bird watchers will note any observations of colour-ringed curlews and report them to the BTO.
You can get in touch with the BTO directly
or by calling 01842 750050, giving details of the colour and position of all colour and metal rings.