Rye Meads is an area of flood plain beside the River Lea near the town of Hoddesdon in Hertfordshire. The Lea Valley has been extensively worked for gravel extraction, leaving a legacy of flooded pits along a north-south axis which forms an attractive natural migration route for many waterfowl and waders, and indeed for many other species of marsh and scrub habitats.
The Rye Meads Ringing Group was established in 1961 to ring and study birds at Rye Meads, and has been active continuously since. Some three to five thousand birds are ringed annually, including large numbers of warblers and several species of duck. Recoveries of birds ringed at Rye Meads have contributed significantly to our understanding of the migration of British birds, and several scientific papers on bird populations and morphology have been based on RMRG data, which now covers over 250,000 birds of 141 species.