The future of red squirrels in the UK is in danger and conservationists are calling for your help.

The endangered mammal needs protection from the invasive grey squirrels introduced in 1876 from North America.

A total of 5,000 volunteers are required in "red squirrels strongholds" across England, Wales and Northern Ireland.

Volunteers will work with partner organisations to monitor the red squirrels, set up camera trips to film their behaviour, educate the public about the species and "speedy report" the larger, common grey squirrels when they move into strongholds for red squirrels.

And volunteers can also do some training to learn how to trap and kill grey squirrels -- by putting them in a bag and knocking them over the head.

“It’s not everyone’s cup of tea and we don’t expect people to do it if they are not comfortable but we do have volunteers who carry out the dispatch themselves,” Dr Cathleen Thomas, programme manager of Red Squirrel United, told the Guardian. She said the organisation has "very strict animal welfare guidelines."

There are more than 2.5 million grey squirrels, largely outnumbering the 140,000 remaining red ones and carrying the squirrelpox virus, which is deadly to the reds.

“In most of the UK there are only a handful of refuges left for red squirrels; without help, experts predict this beautiful and treasured creature could be extinct within as little as 35 years," Thomas said.

"Volunteers are playing a crucial role enabling red squirrels to thrive. Problems arise because grey squirrels are competing with reds for food and places to live, pushing them into areas where they find it more difficult to survive. Greys can also transmit disease to reds."

Scotland alone is home to 120,000 red squirrels, three quarters of the UK population.