Ratcatchers travel round the world to cull isle's rodents

AN INTERNATIONAL team of ratcatchers is to cull 10,000 of the rodents threatening the bird populations on the island of Canna.

The pest controllers have travelled from New Zealand to lay bait for the brown rats which are overrunning the island having arrived on ships about 100 years ago. They are being blamed for a serious decline in bird numbers on Canna.

One of the most severely affected populations is the Manx shearwater, which is now extinct as a breeding bird on the island.

In a 500,000 operation, the National Trust for Scotland, which owns the island, has hired biologists from Wildlife Management International (WMI) to carry out the cull, which has been named Operation Canna Recovery.

WMI has previously removed rodents from Mauritius and Lundy in the Bristol Channel.

But before bait can be laid for the Canna rats, a population of wood mice which also live on the island must be caught so they are not wiped out too.

The 120 mice will be taken to Edinburgh Zoo for a year, then hopefully returned to Canna.

Richard Luxmoore, head of nature conservation at the NTS, said: "The rats have to be poisoned as our research has concluded that seabirds are in serious decline and that the primary cause of this is rats on the island. They also are a pest for the 12 residents who live on the island as they break into food stores and make a nuisance of themselves."

The New Zealand team will use a grid system to lay out bait approximately every 50 metres, placing about 4,000 baits on the island which is four-and-a-half miles long by a mile wide.

The baiting stations are being made by inmates at Saughton Prison in Edinburgh. The team will use 25,000 tonnes of rat poison in the operation.

Because of the rugged landscape of the island, they will have to abseil down cliffs to reach some areas.

It is hoped to begin laying bait in October and continue through the winter, when the rats' food source is scarce.

Mr Luxmoore added: "The target is to have all of the rats eradicated by February."

Funding has come from the EU, National Trust for Scotland, Scottish Natural Heritage, and The Royal Zoological Society of Scotland.