论文部分内容阅读
Islands represent 5% of the earths surface yet support a disproportionately higher amount of the worlds biodiversity.Most extinctions have occurred on islands,and today support ~40% of threatened species.Commensal rodents,introduced on >80% of the worlds islands are one of the greatest threats to biodiversity.Increasing efforts to remove introduced rodents have been successfully implemented on over 500 islands worldwide using a "one time" application of mainly the anticoagulant rodenticides (>70% brodifacoum) delivered into every potential rodent territory using bait stations laid out on a grid pattern,or broadcast by hand or aircraft.However,the use of anticoagulant rodenticides presents an inherent paradox-how to balance efficacy needs (100%) with a desire for no impact to native species.A priori toxicological risk assessments and rodenticide exposure pathway help inform risk identification and mitigation planning.Most measures include reducing exposure to high risk species such as,seasonal timing of the operation when migratory species are absent,or live capture and temporary captive holding until the risk window passes.Many projects have documented impact to native species,but,in most cases the impact is of relatively short duration and populations have recovered to pre-eradication or higher levels.The benefits of removing rodents from islands are unequivocal,with changes documented in mere months to years after the removal operations.The removal of introduced rodents should be undertaken routinely by land managers,with the ecological risk from the use of rodenticides taken into consideration and appropriate mitigation applied as necessary.