Abstract for presentation at Biodiversity Extinction Crisis Conference - A Pacific Response

Non-invasive DNA sampling has been used successfully for a handful of endangered mammal species as a tool for enumerating populations. However, the low quality and quantity of DNA recovered from non-invasive sources (hair and faeces) requires that the technique be thoroughly assessed before it is applied on different species, to ensure individual identification is reliable. In this study, we evaluated the reliability of identifying spotted-tailed quoll (Dasyurus maculatus) individuals using faeces collected from latrine sites, from a well-studied population occurring in Kosiuszko National Park, NSW, Australia. Microsatellite genetic profiles were derived from 209 faeces and were compared to tissue DNA from 22 live-trapped individuals to assess genotyping error. Faecal samples were collected over four-consecutive months (April-July 2005), of which seven weeks overlapped with the trapping program, to allow direct comparisons of population estimates, whereas the four-month faecal collection offered guidance on the sampling intensity required to achieve robust estimates. This study revealed that genotyping errors (allelic dropout) were often present in the 10-locus microsatellite faecal profiles, however using a multiple tubes approach and with comprehensive error checking, individuals were reliably identified. Of the live-trapped population four male individuals were not detected via faecal sampling but additional individuals were detected, 10 over the four-month faecal collection and three during the seven week survey. This study demonstrates that non-invasive faecal DNA sampling is able to provide robust estimates of population abundance directly, but a lengthy sampling regime (up to 7 weeks) is required to detect a large proportion of the population and to also detect individuals over multiple scat samples to allow for statistical population estimation. In conclusion, non-invasive faecal DNA is a reliable sampling tool, however the high expenditure associated with the genetic technique and the lengthy sampling period is likely to prevent it being used as a standard management tool.