Glenarm and east Antrim is home to several habitats where red squirrels continue to thrive.

Larne Council's biodiversity unit has called on the public to help map the populations in woodlands here. The council is keen for members of the public to let them know of any sightings of reds or greys.

Zoe Warrick, Carnfunnock Country Park manager, says that reds are not common in Carnfunnock but greys started appearing in the park about two years ago. The greys, she said, appear to have settled, adding: "It's a bit concerning."

One red squirrel habitat is close to Glenarm. A 1993 report carried out by Queen's University and the Environment and Heritage Service said reds had populated the Sugarloaf Hill area, mainly scrub hazel, around 1991 and were also recorded in coniferous Straidkilly close to Glenarm estate.

A 2007 Irish Squirrel Survey recorded only 47 sightings of reds across Northern Ireland over a seven month observation period. There were 11 sightings of reds and 31 of greys, according to the report. In 1997, the report said, Antrim was the only county without a major grey population. It is thought that the River Bann acts as a natural barrier preventing the greys from colonising.

The report noted: "Only the northeast of the county, i.e the Glens of Antrim, remains to be colonised, and this area still supports several populations of red squirrels. Greys are encroaching on this area from all directions, but particularly from north of Belfast."

Dr Declan Looney, wildlife officer with the Environment and Heritage Service, said there is a good population of reds around Glenarm. "But greys have appeared around that area in the last few years. Once the greys come in within 20 to 25 years there's a reduction in reds - sometimes they're eliminated."

Dr Looney described East Antrim as a "relative stronghold" for the red squirrel population in Northern Ireland. There is no official policy for the eradication of greys - usually involving trapping or shooting - but the EHS has tried several methods. One method involves using bait laced with a contraceptive to prevent grey squirrels breeding. Dr Looney stressed that this method has not been trialed and is in the very early stages of development.

In woodland areas, he said, where conifers and deciduous trees are found together there is a "reasonable chance" the two species can co-exist. Reds prefer coniferous surroundings while greys populate deciduous habitats. Reds though are susceptible to the 'squirrel-pox' virus, which does not affect the grey population.

Another conservation method is to create 'buffer zones' around areas where reds thrive.