Bird lovers in Greater Manchester have launched an appeal to save a flock of ruddy ducks from being culled.
Ruddy ducks are staying closer to their breeding grounds
More than 100 ruddy ducks live on flashes controlled by Wigan Council, but are facing death at the request of the Spanish government.
The birds usually migrate to Spain in the winter and have been mating with the country's own white-headed ducks.
Environmentalists hope the ducks will be spared, as the warmer winter weather has encouraged them to stay in Wigan.
A nationwide cull of ruddy ducks was ordered by the British government in 2003 after complaints from Spain.
Conservationists there feared the indigenous duck was facing extinction as hybrid birds began to dominate.
Hundreds of ruddy ducks have been shot since the cull was ordered.
Wigan council agreed to let government officers onto Pearson's Flash to shoot the ducks this winter.
But Judith Smith, who is involved with the Greater Manchester Bird Recording Group, believes it is time to review the cull.
She said: "The effects of global warming has resulted in ruddy ducks staying closer to their breeding grounds.
"The white-headed duck population in Spain has recovered substantially from a reported 22 in 1977 to around 5,000.
"They now have plenty of choices for mates, and are unlikely to select ruddy ducks even if they were available."
Ms Smith has been backed by opposition councillor Peter Franzen, who tried to submit a motion suggesting the ducks were falling victim to international diplomacy.
But council legal officers ruled that the motion was not admissible and the authority approved the cull.
The cull is also backed by the RSPB, who said: "While it is sad, such measures are necessary.
"We are pleased that the European Commission recognises the serious threat posed to the white-headed duck through hybridisation with ruddy ducks."
Ruddy ducks are common in their native America.
They were brought to Britain in the 1930s for captive wildfowl collections, but some escaped and bred.