Density-impact functions for invasive house mouse (Mus musculus) effects on indigenous lizards and invertebrates

Abstract House mice are among the most widely distributed mammals in world, and adversely affect a wide range of indigenous biota. Suppressing mouse populations, however, is difficult expensive. Cost-effective suppression requires knowing how low to reduce numbers achieve biodiversity outcomes, but these targets usually unknown or not based on evidence. We derived density-impact functions (DIFs) for small fauna tussock grass/shrubland ecosystem. related two indices abundance five lizard invertebrate measured inside outside mammal-resistant fences. Eight 22 DIFs were significantly non-linear, with positive responses skinks ( Oligosoma maccanni , O. polychroma ) ground w?t? Hemiandrus spp.) only where detected scarce (< 5% footprint tunnel tracking rate printing density). K?rero geckos Woodworthia rarely present. A further 9 differentiated from null models, patterns consistent impacts at abundance. This study suggests that unless control programmes commit very abundances, they risk little return effort. Impact studies invasive house largely restricted island ecosystems. Studies need be extended other ecosystems species confirm universality otherwise highly non-linear DIFs.