Once common throughout the country, by the 20th century the pine marten had become extinct from the majority of Ireland, surviving only in a few isolated and fragmented populations mainly in the west. The main reasons for the species’ decline were related to hunting for its fur; loss of habitat through the destruction of forests; direct and indirect poisoning and persecution as a potential predator of livestock/game populations. As all of these factors declined, so has the pine marten recovered so that it has extended its range across most of Ireland. However, the most recent estimate is that there are only about 2,700 individuals on the island, so it is still Ireland's rarest mammal and will remain vulnerable for the foreseeable future.
The spread of the pine marten has coincided with the decline of the grey squirrel, which is now missing from large parts of its former range in the midlands, roughly the same areas where the pine marten is now expanding. It is thought that the pine marten may have a hand in this, by predating on the greys more than the reds, as the greys are heavier, and live more on the ground, making it harder for them to escape. At the moment however, this is only speculation, and further investigation is needed. Ruth will shortly be beginning studies on behalf of The Vincent Trust trying to get further evidence of what exactly is going on, by studying the interaction of both red and grey squirrels with this elusive creature. You can learn more about the pine marten at : http://www.mammals-in-ireland.ie/species/pine-marten