Predator Free 2050 (PF2050) is a government initiative aiming to eradicate selected invasive mammals (mustelids, rats, and possums) from New Zealand (NZ) by 2050. Selecting which of 32 introduced mammal species to include has received little evaluation, yet targeting a few species often results in perverse ecological outcomes given interactions within the invasive guild. We explore how PF2050 could be improved strategically by focusing on biodiversity outcomes instead of selectively targeting invasives, using rodents as an example. Current PF2050 targets include all rat species (Rattus exulans, R. norvegicus, and R. rattus), but not the house mouse (Mus musculus). Mice can be as damaging as rats when competition and predation are removed, negating benefits of rat removal. Multirodent eradications are more cost-effective and prevent mesopredator release. Using a case study, we show adding mice to a rat eradication would raise costs modestly, comparing favorably to independent mouse eradication later, which would be riskier and more socially and economically costly than the preceding rat eradication. Missing the opportunity to tackle all rodents simultaneously, leaving mice to multiply in numbers and impacts, could have serious environmental and socioeconomic consequences. Naïve eradication strategies neglecting ecological expertise risk biodiversity outcomes and NZ's eradication science reputation.

中文翻译：

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小老鼠造成大问题：为什么无捕食者新西兰应该包括家鼠和其他害虫物种

“2050 年无捕食者” (PF2050) 是一项政府举措，旨在到 2050 年从新西兰 (NZ) 根除选定的入侵哺乳动物（鼬科动物、老鼠和负鼠）。从 32 种引进的哺乳动物物种中选择哪一种尚未得到多少评估，但目标是由于入侵群体内部的相互作用，很少有物种经常会导致不正常的生态结果。我们以啮齿动物为例，探索如何通过关注生物多样性成果而不是选择性地针对入侵物种来战略性地改进 PF2050。目前 PF2050 的目标包括所有大鼠物种（Rattus exulans、R.norvegicus和R.rattus），但不包括家鼠（Mus musculus）。当竞争和捕食被消除时，小鼠可能会​​像老鼠一样具有破坏性，从而抵消了消除老鼠的好处。消灭多啮齿动物更具成本效益，并且可以防止中捕食者的释放。通过案例研究，我们表明在老鼠消灭中添加小鼠会适度增加成本，与后来的独立老鼠消灭相比是有利的，后者比之前的老鼠消灭风险更大，社会和经济成本更高。如果错过同时对付所有啮齿动物的机会，导致老鼠的数量和影响倍增，可能会产生严重的环境和社会经济后果。忽视生态专业知识的幼稚根除策略会危及生物多样性的结果和新西兰的根除科学声誉。