Marquesas Archipelago and Rapa in French Polynesia, the next big opportunity to stop extinctions

By Mike Britton, 30 Dec 2015

The contribution islands make to global biodiversity is out of proportion to their land area. Islands provide less than 5% of the Earth’s landmass yet provide habitat for 20% of all bird, reptile and plant species. They can be thought of collectively as biodiversity “hot spots”, containing some of the richest reservoirs of plants and animals on Earth.

Invasive predators, especially rats and cats, represent the greatest threat, but the impacts of habitat modification by herbivores and reduced fitness resulting from introduced micro-organisms are also significant. Three-quarters of all threatened bird species occurring on oceanic islands are at risk from introduced species. A total of 390 islands worldwide support populations of one or more Critically Endangered or Endangered species and one or more vertebrate invasive alien species that threatens them.  That is the threat but it is also the opportunity.  By removing rats and other predators from islands, permanent protection can be provided for the species that call them home – and as is being proven on islands where predators are already gone, recolonization by other threatened species can happen over time.

Big projects, big results.  Having successfully completed the Acteon & Gambier project in 2015, the next big targets for BirdLife in the Pacific, and its partners SOP Manu and Island Conservation are up to 16 islands in the Marquesas Archipelago and at Rapa.

The Marquesas is one of the most important archipelagos for bird conservation in the world.  It comprises six main volcanic islands, four smaller uninhabited islands and many islets. Situated 1,500 km from Tahiti the group is among the most remote in French Polynesia. The project will cover nine priority islands in a programme being developed that will take into account the technical challenges and most importantly getting landowner and political support. The restoration of these sites will provide the opportunity consider taking on predator eradication on the larger more complex islands like Fatu Hiva. The aim will be to secure predator free habitat for 22 species of seabird including three globally threatened (Tahiti Petrel, Phoenix Petrel, Polynesian Storm-Petrel) and at least two globally threatened land birds (Marquesas Ground-Dove, Marquesas Monarch). 

Rapa is the eastern most island of the Austral Islands in French Polynesia. Nine satellite islets ranging in size from approximately one to 26 hectares surround the main island. While little forest cover remains the islands support an assemblage of seabirds unlike those found elsewhere in French Polynesia with eleven species, seven of which are petrels and shearwaters including an endemic form of the White-bellied storm petrel.

Pacific rats, feral cats and goats are present throughout the islands, but their distribution is uncertain. Records of storm petrels on four of the islets suggest these may be rat free, but their presence elsewhere will be impacting sensitive species like storm petrels. Cats are at least present on the mainland and any seabirds there only survive in inaccessible areas. Goats are widespread and their over-grazing is leading to soil erosion creating poor conditions for petrels breeding in burrows. The isolation of Rapa means very little conservation assistance has been provided to this community however, the BirdLife Partner has an established history of working with Polynesian communities and considerable expertise in seabird surveys and invasive species eradication.

Thanks to the support of the David and Lucile Packard Foundation project development, planning and consultation will start in 2016. We need to raise over $1.5 million for the actual operation and that will be our target to allow us to secure the future of the species on these biodiversity hotspots in 2018.