Invasive rodent eradications in French Pacific islands: a critical analysis of past efforts
Wilfried Weiss
A B * , Fabrice Brescia A , Julien Baudat-Franceschi C , Tehani Withers D , Baudouin Des Monstiers E , Simon Ducatez F , Jean-Yves Meyer F G , Thomas Ghestemme D and Eric Vidal B
A
B
C
D
E
F
G
Abstract
The French Pacific Island territories are home to an exceptional terrestrial biodiversity that is threatened by invasive alien rodents causing drastic ecological damage, including the decline of endemic species.
This study compiled and analysed rodent eradication efforts in the French Pacific Island territories from 1982 to 2022, focusing on methods, challenges, and results.
We compiled data from the Database of Island Invasive Species Eradications and local reports. The dataset included a total of 85 eradication attempts conducted on 77 islands, and for each attempt, we extracted information on island size, targeted species, eradication techniques, and biosecurity measures. An attempt was considered successful if a monitoring carried out at least 2 years after the eradication failed to detect any rodent.
In New Caledonia and Wallis, 90% of rodent eradications attempts were successful and concerned quite small island (<60 ha). Eradication attempts in French Polynesia targeted larger islands but showed a lower success rate (56%). Brodifacoum was used in 97% of the operations, and biosecurity measures were uniformly applied, particularly in New Caledonia, where 76% of operations lacked re-invasion prevention protocols.
Our findings suggest that future eradication efforts should follow a global or territorial strategy prioritising islands for conservation. A more rigorous protocol, based on reliable data, is essential to success. Improved local stakeholder capacities is vital to safeguard the unique biodiversity of the French Pacific Island territories.
Keywords: biosecurity, conservation, eradication, French territory, invasive rodents, Pacific, sustainable strategy, tropical Island.
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