Super-rats on Canna.

The National Trust for Scotland has announced plans to cull the rat population on Canna which is endangering the local seabird population, especially the Manx Shearwater. This seems a laudible plan of action for a body entrusted with the care of much of Scotland's natural & cultural heritage. However, the price tag of £500,000 to deal with an estimated population of 10,000 rats would indicate that budget conservation is someone else's concern! There is no doubt that such a project is going to cost money and the job should be done properly if it is done at all. Yet I find it hard to believe that it is going to cost on average £50 per rat to deal with. The fact that the contract for the rat cull has gone to a New Zealand company may have some bearing on this, as does the fact that the local population of wood-mice must first be trapped and removed temporarily from the island while the cull is carried out using 25,000 tonnes of poisoned bait. Yes, that is 2.5 tonnes of poison per rat; the rats will presumably die of obesity if they prove to be immune to the poison.