Search the SPREP Catalogue

To enhance their conservation value, several hundred islands worldwide have been cleared of invasive alien rats, Rattus spp. One of the largest projects yet undertaken was on 43 km2 Henderson Island in the Pitcairn group, South Pacific, in August 2011. Following massive immediate mortality, a single R. exulans was observed in March 2012 and, subsequently, rat numbers have recovered. The survivors show no sign of resistance to the toxicant used, brodifacoum. Using pre and post-operation rat tissue samples from Henderson, plus samples from around the Pacific, we exclude re-introduction as the source of continued rat presence. Microsatellite analysis of 18 loci enabled comparison of genetic diversity of Henderson rats before and after the bait drop. The fall in diversity measured by allele frequency change indicated that the bottleneck through which the breeding population passed was probably around 50 individuals, representing a census population of about 60-80 animals. This is the first failed project that has estimated how close it was to success.

PACC reports

Statement of purpose, the 2010 Pacific forum leaders' and Forum economic ministers' directive on reporting acknowledged the need to streamline global, regional and national reporting to reduce the reporting burden at the national level in the Pacific. For the environment sector, member countries of the Secretariat of the Pacific Regional Environment Programme (SPREP) endorsed plan for the establishment of a regional state of environment framework by 2012 and streamlined reporting by 2015. These goals are formalised in the SPREP Strategic plan 2011-2015. A workshop was jointly convened by the Pacific Islands Forum Secretariat (PIFS) and SPREP in March 2012 in Fiji to provide a vision for more effective and streamlined reporting in the Pacific region. This process will be taken forward by relevant regional mechanisms such as the Pacific Plan, Forum Compact and the Council for Regional Organizations in the Pacific (CROP) to achieve the vision presented here.

Reports from the PACC project

Technical report