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The grey squirrel threat
It is widely accepted that a significant factor in the decline of red squirrels was the to the UK in the late nineteenth century. Grey squirrels threaten red squirrels in two main ways.

Firstly, they compete with red squirrels for food. Grey squirrels eat seven times more food per hectare than red squirrels. They aggressively compete with the red squirrels for food, and they also eat food before it is ripe enough for red squirrels to eat.

Secondly, grey squirrels carry a virus called , which they are immune to, but which is deadly to red squirrels. It's estimated that 60% of grey squirrels carry the virus and they suffer no ill effects from it, but if a red squirrel catches it, it will be dead within weeks. Grey squirrels have probably evolved immunity to the virus, but because it is new to red squirrels, they are not immune, and it is lethal to them on an epidemic scale.

There's more detail on how the greys threaten the reds on the .

Conservationists now estimate that there are only about 160,000 red squirrels nationwide compared with 2.5 million greys.

Plans to save them
So what do we do about this? Like all conservation issues there has been a lot of debate about the best course of action. It has been argued that red squirrels are a lost cause, and it is too late to save them.

But it shouldn't be argued that it's natural selection, because the problem is undoubtedly man-made. were never equipped to compete with grey squirrels, having evolved in Europe alone. Grey squirrels in contrast came from a highly competitive environment in North America.

One way to conserve the reds is to control the greys. There are two main approaches here. Some believe in attempting to eliminate grey squirrels altogether. But this would require huge resources, would be controversial, and may not even be possible. The favoured approach is to protect red squirrels in designated areas and cull grey squirrels in the buffer-zone areas surrounding them.

Grey squirrel control is carried as humanely as possible, by trained, licensed individuals. A clever trapping system based on weight balance is used. It means that red squirrels can escape from the traps, but the greys can't. The traps are covered, so the squirrels in them aren't exposed but are kept warm and dry, and checked twice a day.

These red squirrel refuges are also managed and enhanced in other ways. For example, ensuring they have the correct composition of tree species to suit red squirrels as much as possible.

Recently money has also been put into study to map grey squirrel control efforts that are currently in place. This will take into account work by landowners, institutions, volunteers and local groups, with the aim of gaining a greater understanding of existing work and helping with future red squirrel conservation strategies.

There are also other long term strategies that are being researched. For example for red squirrels against the squirrelpox virus, but this is thought to still be about ten years off.

There has also been to stop the spread of grey squirrels. But there are many complications with this. For one, how do you feed the medication to grey squirrels without affecting other rodents? Difficult, considering that squirrels cache a lot of food.

So what do you think? Please tell us below.