These maps, sourced from Bioforest - Habitat Requirements of Hen Harriers in Ireland, show how the Hen harrier population has fallen to critical levels. The numbers fell between the 1968 to 2001 surveys from about 300 to about 150 pairs. In the most recent survey (Barton et al 2006) 132 territorial pairs were confirmed. The proposed Special Protection Areas (SPAs) for the Hen harrier were reduced from 9 to 6 in the final designation. Unfortunately the most successful regions were excluded such as the Ballyhouras and the Nagles. The NPWS state in the 6 SPA site synopses that 'the main threat to the long-term survival of Hen Harriers within the site is further afforestation' and that within one SPA the numbers fell 'due to habitat change as a result of maturation of conifer plantations'.