Red squirrels are under threat in the UK from grey squirrels

Earlier this year, the Lake District National Park Authority backed an action plan to protect the native reds from being over-run by the greys.

After five weeks of checking 32 traps, only three greys have been caught on the Keswick area.

Ranger Val Edmondson said approved procedures to humanely trap and destroy greys meant a major fall in numbers.

She said: "The success of this exercise, resulting in grey sightings reaching an all-time low, is down to a professional approach by marksmen ensuring greys are controlled in a sensitive way as soon as they are reported."

If we want to keep our reds we are going to have to control the greys for ever Ranger Val Edmondson

She said local people and visitors had reported sightings after reading posters explaining the plight of the reds and the differences in species.

She added: "Sadly, we can never be complacent. Maybe because other areas don't go to the same lengths to control their greys, they will continue to come this far north.

"If we want to keep our reds we are going to have to control the greys for ever."

Nationally, there are around 2.5 million greys and only about 160,000 reds.

The authority says the Keswick and Derwent Valley area has a strong, healthy population of reds, but greys compete for food and also carry the parapox virus, which causes a slow painful death in the reds.