Detecting and protecting the threatened Kangaroo Island dunnart (Sminthopsis fuliginosusaitkeni)

Abstract

Reliable and cost-effective monitoring methods are a critical component of conservation management practices that work to prevent the extinction of threatened species. We evaluated the best means of monitoring the threatened Kangaroo Island dunnart (Sminthopsis fuliginosus aitkeni, hereafter KI dunnart). Variation in detection probability and cost was examined between four trapping methods. We then compared the occupancy of the KI dunnart in a 2017-2018 survey to a survey from 1999 to 2001. Across the 2017-2018 survey, the KI dunnart was detected at only five sites and was detected most frequently using camera traps on drift fence lines. The taxon was estimated to occupy 27% (95% confidence interval: 7-65%) of sites in the eucalypt woodlands of western KI. Of the methods that have successfully detected KI dunnarts, cameras on fence lines were the most cost-effective. Power analysis suggests that future monitoring surveys in spring and autumn must survey at least 55 sites to be capable of detecting a 60% decline in the KI dunnart population, and 26 sites to detect an 80% decline. Ongoing intensive monitoring is required to assess the population trajectory of the taxon and support its persistence on the island in the long term. K E Y W O R D S