The May 2015 issue of the international journal Biological Conservation is dedicated to tropical island conservation, focusing on eradicating rats using techniques pioneered in New Zealand and now used around the globe. The special issue was edited by Dr. James Russell of the School of Biological Sciences and Department of Statistics at the University of Aukland and Dr. Nick Holmes of US-based NGO Island Conservation.

Invasive rats have travelled with humans to over 80% of the world’s islands groups, where negative impacts have been recorded on 173 species of plants and animals, many of which are imperiled. Rat eradication techniques allow rats to be removed from islands, one of the most significant actions to help restore these ecosystems. However, as the authors illustrate in the special issue, rat eradications on tropical islands have had a lower success rate than those in temperate zones, and recently dropped below 80 percent, creating a critical gap in our island restoration toolkit.

The special issue of the journal compiles papers following a Tropical Rodent Eradication Review and Symposium convened at the University of Auckland in August 2013, and attended by more than 30 experts in the fields of island ecology, rodent ecology and rodent removal from around the globe. The Symposium was initiated by Island Conservation and convened by the Pacific Invasives Initiative, Grupo de Ecología y Conservación de Islas, BirdLife International, the Royal Society for the Protection of Birds, the US Department of Agriculture, the National Fish and Wildlife Foundation and the New Zealand Department of Conservation. The workshop goal was to assess current approaches and assumptions in rodent eradications and develop recommendations to improve the success rate of future rodent eradications undertaken on tropical and sub-tropical islands worldwide.

“This special issue and symposium represent an exciting collaboration among key rodent biologists and island restoration practitioners,” said Island Conservation’s Director of Science, Dr. Nick Holmes. “The research and recommendations allow us to tackle a critical conservation need; how can we more effectively protect our world’s imperiled tropical island species from the threat of invasive rodents?”

The most immediate response to rat eradication is the recovery of suppressed plants (Campbell and Atkinson, 2002). Invasive rats were removed from Palmyra Atoll, Line Islands in 2011. Before rat removal, scientists could not find any native Pisonia grandis seedlings on the atoll. Today, Pisonia grandis seedlings are abundant and trees that sprouted in 2011 are now towering overhead.

The special edition in Biological Conservation includes ten peer reviewed papers focused on cutting edge tropical island research on rat biology and management, recommended best practices for rat eradication, and emerging technologies which might be game-changing for island restoration. The outcome of the workshop and special issue represent a path forward for improving research and eradication of rats on tropical islands. Ultimately, this means we can work towards saving more endangered island species faster in the tropics where conservation is most sorely needed.

The special issue can be accessed here, including free–to-download copies of the articles: Tropical island conservation: Rat eradication for species recovery and Best practice guidelines for rat eradication on tropical islands.

Media enquiries please contact Heath Packard heath.packard@islandconservation.org