Post-eradication monitoring :
This mission aimed to maintain continuous rat monitoring across Teti'aroa Atoll, in two distinct contexts. First, the regular surveillance of Onetahi, a motu that was not treated in 2025 but which represents the atoll's main entry point, and Second, post-eradication monitoring of the motus treated in 2025 (Tiaraunu, Tauvini, Ahuroa, and the western side of Hiraanae), aimed at verifying the continued absence of rats across these restored areas.
Main objectives :
This mission aimed to maintain continuous rat monitoring across Teti'aroa Atoll, in two distinct contexts. First, the regular surveillance of Onetahi, a motu that was not treated in 2025 but which represents the atoll's main entry point: all goods are unloaded here, and it is where the built infrastructure, permanent residents and daily human activity are concentrated. A confirmed rat detection by camera trap in late September 2025 had already triggered the intervention of a licensed pest control agent, making reinforced monitoring essential to prevent any new accidental introduction. Second, post-eradication monitoring of the motus treated in 2025 (Tiaraunu, Tauvini, Ahuroa, and the western side of Hiraanae), aimed at verifying the continued absence of rats across these restored areas.
Summary of field activities :
The mission covered several motus progressively. On Onetahi, 30 cameras were checked and 16 additional ones deployed, supported by 44 bait platforms replenished daily with coconut. Several verbal rat reports were received during this period. Some turned out to be geckos after image review, while others could not be confirmed despite reinforced monitoring measures.
On Tiaraunu, 27 cameras were deployed and progressively repositioned from the southern end towards the centre of the motu based on daily check results. Several transects were also opened, meaning marked lines cut through the vegetation to allow systematic terrain coverage. No rat detection was recorded.
On Tauvini and Ahuroa, 9 cameras were installed on each motu and transects progressively opened. On Ahuroa, particularly dense vegetation made movement and monitoring difficult. Checks revealed only non-target fauna: coconut crabs, birds, lizards and hermit crabs. On Hiraanae, 5 cameras were installed on the Hoa-facing side (west) as a precautionary measure, given the proximity of Ahuroa and the risk of rat movement between the two motus via this tidal channel.
Recurring technical issues were reported throughout the mission, including faulty SD cards, battery failures and ageing bait platforms in need of replacement.
Preliminary results :
No rat detection was recorded on any of the motus under post-eradication monitoring. On Onetahi, verbal reports could not be confirmed despite the measures put in place.
Perspectives :
Reinforced monitoring will be maintained on Tiaraunu, a motu where rats persisted during previous campaigns, to ensure the complete absence of any new individuals. A rodenticide baiting operation is also planned for April on Onetahi.