An experimental cull of grey squirrels on Angelsey looks likely to help red squirrels reestablish themselves on Anglesey, after reintroduction in 2004. A similar cull is being considered for mainland Britain.

Red squirrel numbers have continued to drop ever since their larger grey cousins were introduced from America in the 19th century. There are now only about 120,000 red squirrels left in Britain whereas there are three million greys.

Grey squirrels spread squirrelpox, which they are immune to but red quirrels aren't. Grey squirrels are also better able to food food and shelter whereas the red squirrels have a limited diet and prefer coniferous woodland.

The RSPCA has attacked the cull because it prioritises one species over another. We'd all like to see squirrel nutkin return to Britain, but are we prepared to kill millions of grey squirrels to make it happen. On the other hand, the red squirrel is at risk of extinction, so could this be a necessary evil?