Ring-necked Duck was originally described from a bird that
was for sale at Leadenhall Market in London in 1801, it was
apparently 'obtained' in the Lincolnshire Fens. The first
documented British record comes from as recently as 1955.
The scientific name 'collaris' is a clear reference to the
birds cinnamon neck collar, however some authorities believe
it should be called Ring-billed Duck due to its quite
obvious bill pattern.
There have been four Ring-necked Ducks reported from S.
Gloucestershire;
2000: (2)
On April 13th an adult male was identified at Oldbury Power
Station on the small pool near Lagoon III and would remain
until May 4th; On November 2nd a male visited Orchard Pools
near Severn Beach.

Ring-necked Duck at Oldbury Power Station. April 2000. Iain
Leach.
1988: (2)
Two, both males were found on April 2nd off New Passage.
This occurrence constitutes the first report of this species
for S. Gloucestershire.