The feral cats that inhabit South Africa's famous Robben Island have prompted a row between animal welfare officials and conservationists.
South Africa's most famous prison has become a tourist attraction
Robben Island, in Table Bay near Cape Town, is best known as the place where Nelson Mandela and other political prisoners spent decades in jail.
Feral cats - the descendents of prison warders' pets - are blamed for killing endangered reptiles and birds.
A programme to shoot the cats resumed recently, after being suspended.
The shooting was suspended to allow the Society for the Prevention of Cruelty to Animals (SPCA) to trap the cats, sterilise them and return them to the island to help control the rat population.
But the SPCA succeeded in trapping only eight cats.
At a meeting last week, officials of the Robben Island Museum - the custodian of the island - wildlife experts and SPCA representatives, a decision was taken to resume the shootings immediately as the cats were "having a devastating effect on most of the endangered birds" on the island.
Robben Island is home to 132 species of bird
"Cats don't belong on offshore islands where there are breeding birds," said Les Underhill of the University of Cape Town's Avian Demography Unit, which monitors the island's seabird populations.
Robben Island is homes to about 132 bird species and about 7,000 breeding pairs of African penguins, as well as reptiles such as the dwarf chameleon.
The SPCA agreed the cats needed to be removed, Cape chief executive Allan Perrins said.
But he said the society favoured "an effective and efficient, non-confrontational, non-lethal sustainable solution".
"All the focus at the moment is honed in on cats being the primary suspect," Mr Perrins told the AP news agency.
He said that on a nearby island, mice three times the size of an average house mouse were found to be decimating seabirds, and that rabbits might also be responsible.
The SPCA will be allowed to continue trapping and to monitor the humaneness of the shootings.
Robben Island was used as a leper colony, military base and prison from the 17th to the 20th century.
Since the transition to democracy in South Africa it has been redeveloped as a tourist attraction and memorial to the struggle against apartheid, and in 1999 was declared a UN world heritage site.