There is bad blood between red and grey squirrels. But now the governments on both sides of the border are planning to enter the squirrel war with a controversial culling plan.

BBC NI rural correspondent Martin Cassidy takes a look at the ethical dilemma facing conservationists

The red squirrel is being threatened by the grey

All is quiet high up in the tree-tops and there is nothing here in the stillness of the Fermanagh air to suggest that this pine forest is a war zone.

But now there is movement above in the canopy and a red squirrel comes darting though the branches, stopping to feed on pine seeds.

A shaft of sunlight illuminates this small forest mammal and its richly coloured coat.

Could an animal so alive and alert be really facing extinction?

In another forest near Belfast, Dr Robbie McDonald raises his binoculars to his eyes and surveys the tree-top environment.

He is one of a group of conservationists tracking the decline of the indigenous red squirrel and the unrelenting march of the larger, more assertive grey.

The grey squirrel, he says, is better at exploiting a wider source of food sources and for highly active animals with a big appetite for high energy nuts and seeds, that is significant.

There is plenty of food around just now, but as the winter progresses supplies of nuts begin to run low. The arrival of spring can herald a hungry time and the red stands little chance of getting a share.

The real problem is that while the two squirrel types have similar appetites, their table manners are poles apart.

Quite the little lady and gentleman, our own red squirrels wait for nuts and seeds to mature.

The brash American greys though observe no such etiquette.

The bigger grey, will grab whatever is to hand, eating barely ripened nuts and seeds.

So picture the scene, as the grey squirrels gather in their harvest, they leave little or nothing for the more conservative red squirrels.

An added problem is that grey squirrels can carry a disease which red squirrels have no defence against.

And so, year by year red squirrel numbers have been falling while the greys have happily been advancing across the country.

The grey squirrel could be facing a cull

But it is still not too late to save the red squirrel says Mr McDonald a researcher at Queen's University, Belfast.

Time though, he believes, is running out for the red squirrel and that is why he is backing what could prove a controversial new species action plan.

With the remaining red squirrel populations hemmed in to ever decreasing areas, the new species action plan focuses on halting the advance of the greys.

Controversially the action plan suggests strategic culling of greys to help maintain colonies of red squirrels in areas where conservationists hope they might be able to survive.

Mr McDonald said that if nothing is done then "it's fairly clear that red squirrels face extinction in this part of the world".

Baited cages

Culling greys though, he accepts, poses a dilemma for ecologists and conservationists.

"In this case it's clear to me the only solution for conserving red squirrels in this part of the world is to kill grey ones," he argues.

From other peoples perspectives, he accepts, grey squirrels have every much right to life as reds.

It's a dilemma though which the new action plan insists society must face up to.

It envisages the establishment of safe areas for remaining colonies of reds and culling grey squirrels which threaten those retreats.

John Milburne of the Environment and Heritage Service has been working on the squirrel action plan.

"It's really a matter of finding an area where there are no grey squirrels at the moment and controlling the greys before they get in there," he says.

But he warns that it will be expensive and difficult "because we will need the co-operation of landowners in surrounding areas".

Safe zone

It would also mean finding resources for squirrel culling and to monitor the red squirrel reserves.

But how would the culling be carried out?

Trapping is generally seen as the most effective method of capturing squirrels.

A small cage baited with squirrel food is placed on the forest floor.

Attracted by the food, the squirrel enters the cage and the door springs shut.

Live trapping like this means any red squirrels which are caught can be released while the greys would be put down.

At this stage, the species action plan is being considered by government agencies on both sides of the border.

Accepting the plan would mean a long-term commitment by the authorities to protecting the red squirrel safe areas.

To undertake a cull and then stop again in a year or two would mean the grey squirrels would have died for nothing and the red squirrel reserves would eventually be overrun by their competitors.

"We have to think of this in strategic terms," says Mr McDonald, who has been thinking about the geography of the areas where red squirrels could be defended.

The areas of Northern Ireland that are most isolated, he believes, offer the best opportunity.

It is places like the Ards peninsula and remote conifer forests in north Antrim where red squirrel conservation would be concentrated.

The decision on whether to proceed with the species action plan will be made soon.

While the culling of grey squirrels may raise concerns, Dr McDonald said that with a limited number of mammal species on the island of Ireland, to lose one would be a great shame.