Pine marten (Martes martes) distribution and abundance in Ireland: A cross-jurisdictional analysis using non-invasive genetic survey techniques

On the Island of Ireland, pine martens (Martes martes) exist at the western edge of their global geographic range in the least forested region of Europe. The species has undergone substantial declines in abundance and distribution during the 20th century. Here, we report on the first cross-jurisdictional (Republic of Ireland and Northern Ireland) survey that aimed to investigate current pine marten distribution, assess any recent historical change and provide preliminary estimates of population abundance.A standardised non-invasive survey technique that used scat-based transect surveys and DNA analysis to confirm scat identity was deployed in 258 10 km national grid squares during 2005–2007. In the Republic of Ireland, an occupancy rate of 59.6% was found. Comparisons with historical data indicated that a range expansion of pine marten had occurred over the last 30 years. Indicative core population range extended to over 50% of the land area with population abundance estimates of 2740 individuals.In Northern Ireland, an occupancy rate of 56.7% was determined with the population largely concentrated in western areas. There was little or no evidence of any recent expansion from core population areas (18% of land area) despite recent increases in forest cover and full legal protection. Population abundance estimates of 320 emphasise the critical requirement for action to conserve this species.The pine marten is one of the rarest wildlife species in Ireland and, based on our studies, an evidenced based conservation strategy that promotes a sustainable future for the species needs to be developed.