Videos, audio clips and information about the red squirrel species.
Chris and Kate travelled to the Lake District in Cumbria to visit the front line of the red squirrels' struggle against the greys.
You can offer your opinion about The red squirrel debate on the Autumnwatch blog.
Red squirrels are small and shy mammals with distinctive red fur. This fur darkens to a rich brown in the autumn. They have long bushy tails and pointed ear tufts, and a buff-coloured chest.
Red squirrels are widespread across Europe but British populations have been in dramatic decline over the last 50 years due to loss of habitat, diseases such as pox and the introduction of and competition with the grey squirrel.
Red squirrels, native to the UK, are thought to have been resident in Cumbria for about 6,000 years. The greys were introduced to this country in the late 1800s. They appeared in the area Chris and Kate visited in around 2001, at the same time as the foot and mouth disease.
One key issue for red squirrels is that they are relatively specialised feeders. Greys, on the other hand, will eat all kinds of food and in large amounts. Greys are thought to eat around seven times more per hectare than red squirrels. They are also much more aggressive when competing for this food. Another problem is that they will eat some things before they are ripe enough for the reds.
Greys also carry diseases, namely the squirrel parapox virus. They have developed an immunity to this virus but infected and untreated red squirrels are thought to have a mortality rate of 100%.
You can help red squirrel conservation by registering your sightings with the national squirrel sightings database run by the Save our Squirrels project in England. In Scotland there is the Scottish Squirrel Survey and in Wales the Red Squirrel Project.
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