Restoration of Kamaka Island, a sanctuary for Gambier biodiversity

Island Conservation
Published: 31 May 2023
Last edited: 31 May 2023
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In June 2015, an operation aimed at restoring islands of interest was carried out in the Gambier and Actéons islands. The eradication of the targeted introduced species was a success on all of these islands, except Kamaka, where the eradication of the Pacific rat (Rattus exulans) failed. In 2022, a second attempt via drone aerial baiting was made to preserve this site. It succeeded, and in 2023 rats were no longer found. The project was set up with the help of ENVICO, a drone company based in New Zealand, the landowners of Kamaka, Island Conservation, local members of the community & the Town hall of the Gambier.


By removing rats, the project has contributed to the conservation of rare seabird species, such as the Polynesian Storm-petrel (Nesofregetta fuliginosa) and many other indigenous species of the island. In addition, the local community has benefited from this restoration project through increased natural resources, reduced risk of diseases and increased economic opportunities. 


Scale of implementation
Forest ecosystems
Tropical evergreen forest
Invasive alien species
Species Conservation and One Health Interventions
Invasive Species Management/Removal
One Health
Biodiversity-health nexus
Loss of Biodiversity
Invasive species
Lack of food security
Aichi targets
Target 9: Invasive alien species prevented and controlled


French Polynesia


  • Kamaka is the only island where the large-scale rat eradication operation of 2015 has failed. Once a site has one failed attempt, it is important to assess why and how to counteract the reason why it failed.
  • Kamaka is very close geographically to two important nesting sites of Polynesian Storm-petrel: Manui and Teiko islets. Rat presence on Kamaka makes this species unable to nest on the island. It is also a risk that rats would one day swim to these near islets to invade these sites, which would be catastrophic for this endangered seabird species.
  • Kamaka hosts many plant species, some very rare, and rats presence stops the development of seedlings
  • Kamaka has private owners who had to constantly distribute rodenticide to control rat population around their vegetable gardens and fruit trees. Kamaka is also an important site for local fishermmen for coastal crabs, which rats also eat. 


  • Kamaka seabirds, indigenous plants and insects, as main beneficiaries.
  • Kamaka local owners and their families, since now they can eat fruits and vegetables produced on the island. The locals will have increased resources in coastal crabs.

How do the building blocks interact?

  • Block 1 is the logistical and methodology planning - which was the creation of the organisation plan, a plan that needed to work for our partners (Island Conservation and Envico);
  • Block 2 is the project implementation on the field, and the issues that we managed to by-pass since we managed to adapt to the situation rapdirapidly
  • Block 3 is related to communication of the project among the local community, and having them involved in the protection of the site.

In Kamaka, a private property and remote island from the villages of Mangareva, the risk of reintroduction of rats is minimal and depends on the visitors of the island (especially on the owners of the island). Biosecurity measures for the safety of the island will still have to be carefully and rigorously monitored.


This type of project would be feasible at other sites in French Polynesia. Kamaka, being the first project by Drone, will serve as an example for other future projects and other important sites for seabirds in Polynesia. 


  • Rat eradication was successful on Kamaka and local capacities were increased for SOP Manu, owners of the island and local workers.
  • Monitoring of the absence of rats on indigenous species was completed on:  (1) bird species present and reproductive success, (2) the proportions of seeds and seedlings (of Koariki Terminalia glabatra) on the ground, (3) the abundance of mosquitoes and (4) the abundance of coastal crabs.
  • Most significant impacts collected during monitoring was on plants (seeds and seedlings) and crabs, which numbers have increased significantly since the eradication project
  • As for seabirds, it is difficult for now with the time allocated by the grant to really measure a significant impact, as there are different breeding seasons, meaning that the data is very variable. Long-term monitoring will be needed in the future.
  • Mosquitoes numbers don't seem to have reduced in numbers as of yet.
  • Two successful training sessions of a local environmental NGO (Toromiki no Mangareva) was completed. Topics were Seabirds identification methods, threats and conservation actions (i.e. biosecurity measures).


Hadoram Shiriai

Kamaka was bought by Johnny Reasin’s father in the 1960s. The family lived there for many years and built two houses, a pond and other structures. Since the 1990s, Johnny became the owner and was the only permanent resident of Kamaka. In June -July 2015, Kamaka was part of a larger operation led by SOP Manu, BirdLife International and Island Conservation, targeting nine populations of five species of invasive alien vertebrate at a total of six sites in the Acteon group and the Gambier archipelago. All target pest populations were successfully removed except for the R. exulans population on Kamaka. A genetic analysis confirmed the rats found a year later were survivors of the target population. 


Unfortunately, Johnny passed away in late 2017 and is now buried in Kamaka. Since then, Tehotu Reasin, Jonny’s son, is the new joint owner (with his sister). Like his late father, Tehotu supports the restoration of Kamaka to benefit the native flora and fauna. 


Kamaka has no reef protection to the South and as such is exposed to southerly weather conditions and in particular the Southeast trade winds (‘Mara’amu’; begins at the end of April and last till October‐November) which often produce sea conditions preventing access by boat for several weeks at a time during this period. The mostly rocky coastline is a mix of cliffs with overhangs, gentler slopes, boulder piles and rocky intertidal zones; the only sandy beach is at the north of the island, which is the only access point.


Kamaka Island is not an easy island to work on, but it is very beautiful and is an important breeding ground for many seabirds, such as the 'Karako' (Tropical Shearwater), 'Kokokoko' (Christmas shearwater), 'Noha' (Tahiti Petrel), etc. All seabirds have local names in the Mangareva language, meaning that they were important for the local culture of the Gambier Archipelago. SOP Manu and many locals that have worked on the restoration of Kamaka, dream that the small ‘Kotai’ (Polynesian Storm-Petrel), which only breeds on nearby Manui and Teiko Islets, will one day come back to breed on Kamaka! I also consider myself a privileged person to be able to work there. When I hike to the top of the island and look at the beautiful view, I think about all of our conservation efforts and hope that this island becomes a sanctuary for many seabirds in the future.   

Contributed by

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Tehani Withers Société d'Ornithologie de Polynésie Manu, BirdLife International