THREATENED SPECIES SCIENTIFIC COMMITTEE Established under the Environment Protection and Biodiversity Conservation Act 1999 The Scientific Committee finalised this assessment on dd/mm/yyyy. The Minister amended the list of threatened species to reflect the Committee’s advice on dd/mm/yyyy <insert date of Minister’s decision>. DRAFT CONSERVATION ADVICE FOR PUBLIC COMMENT – DECEMBER 2019 DRAFT Conservation Advice Sminthopsis aitkeni Kangaroo Island Dunnart Cover image: Kangaroo Island Dunnart © Jody Gates Approved on DD MM YYYY Conservation Status Sminthopsis aitkeni (Kangaroo Island Dunnart) is listed in the Endangered category of the threatened species list under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act). The species is eligible for listing as Endangered because prior to the commencement of the EPBC Act, it was listed as Endangered under Schedule 1 of the Endangered Species Protection Act 1992 (Cwlth). The Kangaroo Island Dunnart is also listed as Critically Endangered by the International Union for Conservation Nature (IUCN) under the criterion of B1ab(i,ii,iii,iv,v)—i.e. small extent of occurrence, few locations and continuing decline. Species can also be listed as threatened under state and territory legislation. For information on the current listing status of this species under relevant state or territory legislation, see http://www.environment.gov.au/cgi-bin/sprat/public/sprat.pl Scientific Name The Kangaroo Island Dunnart is listed under the EPBC Act as Sminthopsis aitkeni. Taxonomic status is not firmly resolved, and further research is a priority to resolve the affinities and nomenclature of the Sminthopsis fuliginosus aitkeni and Sminthopsis griseoveter aitkeni complex (Jackson & Groves 2015). Description The Kangaroo Island Dunnart (hereafter referred to as the KI Dunnart) is the only species of dunnart found on Kangaroo Island and is endemic to the island. It is similar in morphology to the Common Dunnart (Sminthopsis murina) and was originally recorded as this species. However, electrophoretic and morphological studies in the early 1980s distinguished the KI Dunnart as a separate species (Baverstock et al. 1984 & Kitchener et al. 1984). More recent studies suggest it may be a subspecies of the Grey Bellied Dunnart (Sminthopsis griseoventer (now fuliginosis) (Kemper et al. 2011). The KI Dunnart is notable for its dark grey sooty dorsal pelage and light grey ventral pelage. The KI Dunnart is differentiated from other small mammals on Kangaroo Island by its pointed snout and wide, square-shaped ears (Hohnen 2019). The thin tail is always longer than the body and clearly bicoloured (Menkhorst and Knight 2004). Adults of this species grow between 80-90 mm long and weigh up to 25 g (Strahan 1998). Distribution Historical records from 1969-1976 reported that all KI Dunnart sightings were from the central and eastern parts of Kangaroo Island in areas where intensive land clearing was occurring. Its current distribution on Kangaroo Island is unknown, although since 1990, all records of the KI Dunnart are from the western end of the Island within Flinders Chase National Park, Ravine des Casoars Wilderness Protection Area and areas of remnant native vegetation on private land (Figure. 1). Survey work in 1999-2001 by Gates (2001) detected 22 individual KI Dunnarts at six sites, within the Flinders Chase National Park. Surveys by Hohnen et al. (2019) in 2017-2018 detected individuals on seven occasions at five sites all in the western end of the island. Surveys conducted between April 2018 and May 2019 detected KI Dunnarts on 42 occasions at six sites within areas of remnant native vegetation on private land (H Groffen. pers comm 2019). 2 The majority of survey effort on western Kangaroo Island focussed on easily accessible areas and from this, it is likely that KI Dunnarts occur at other sites within Flinders Chase National Park, Ravine des Casoars Wilderness Protection Area and in surrounding remnants of native vegetation, including large areas of private conservation land. It is estimated that KI Dunnarts occur in approximately 27% (95%CI 7-65%) of the eucalypt woodlands on the western end of Kangaroo Island (Hohnen et al. 2018). The area of occupancy for the KI Dunnart has been identified as approximately 8% (352 km2) of the total area of the island (4405 km2). Although early records of the KI Dunnart come from the central and eastern parts of the island, clearance, modification and fragmentation of these habitats has reduced the likelihood of KI Dunnarts still occurring there. Since 1979 there have been no confirmed detections of the KI Dunnart east of North Coast Road and Gosse-Ritchie Road (longitude 170°E). Extensive surveys have been conducted on the eastern side of Kangaroo Island (Herbert 1996; Robinson & Armstrong 2000; Jones et al. 2010; Gates 2001 & Molsher et al. 2019), including the Dudley Peninsula, and they have failed to detect KI Dunnarts. However, these surveys have primarily used pitfall traps and rarely reached the 51 days required of this particular method to achieve a 95% detection probability (Hohnen et al. 2019). Figure 1. The location of identified KI Dunnart records including collected specimens, trapped and photographed individuals. 3 Figure 2. Predicted dunnart occurrence based on species distribution modelling (Hohnen et al. in review a). Cultural Significance There are no Indigenous cultural values known for this species. Relevant Biology/Ecology Diet Dunnarts (Sminthopsis spp.) are primarily nocturnal, opportunistic foragers and predominantly feed on insects, spiders and other terrestrial arthropods (Van Dyck 2008). One preliminary study using scat analysis (Gates 2001) of 14 captured individuals identified spiders and ants as the most common food group recorded in the diet of the KI Dunnart, occurring in 59% and 56% of scats (n=25) respectively. Beetles and scorpions were also commonly consumed, being recorded within 36% of scats. The remains of a centipede and grasshopper were also recorded in one scat. These results demonstrate the expected diet of KI Dunnarts as all food groups recorded were ground-dwelling invertebrates. Reproductive Biology There is still limited understanding about the reproductive cycle of KI Dunnarts. Most dunnart species have been found to be polyoestrous (capable of breeding several times a year), with rapid maturation of young that require minimal parental care (Lee & Cockburn 1985). Polyoestry has been shown to provide a survival advantage for the Common Dunnart in the unpredictable and short-lived conditions that categorise early-mid stage post-fire habitat (Fox and Whitford 1982). All live captures during the 1999-2001 surveys occurred between January and May with over half being juveniles/sub-adults (<16 g). No adult females were caught during this survey (Gates 2001). Of interest though is the fact that at one site, juveniles of less than 11 g were captured in January and March in the same year. The most likely explanation for the two cohorts of juveniles is that females are polyoestrous, which is consistent with reproductive cycles observed for Common Dunnarts (Fox & Whitford 1982). Based on the growth and development of Common Dunnart young (Fox & Whitford 1982), these juveniles were estimated to be approximately 65- 4 115 days old. Taking into consideration that the gestation period is approximately 12 days (Fox & Whitford 1982), it is believed that mating occurred in mid-September to early October and in November to December. Life History The period of juvenile dependency is unknown, although studies on the similar Common Dunnart have shown this period to be approximately 65 days (Fox & Whitford 1982). As outlined above, the most recent live captures occurred post-breeding season in late summer and autumn (Gates 2001). Although no data exist for the life expectancy of the KI Dunnart, based on the life histories of other Sminthopsis spp., females may survive to breed in a second year, whereas males are less likely to survive beyond one breeding season. The predominance of captures of juveniles in summer and autumn provides circumstantial evidence to support this. Studies at known dunnart sites have shown that dunnarts are consistently detected throughout the year but detections decrease over winter (P. Hodgens. pers. comm 2019). The home range dynamics and patterns of movement remain a critical gap of knowledge for this species. Radio tracking of some individuals indicated that range lengths are approximately 200- 300 m, however, seasonal patterns of home range use and differences between sexes in use of habitat and space are not clear (Gates 2001). The dispersal patterns of juveniles from their natal range are also unknown. A range of short term movement patterns are displayed by closely related species of dunnart, with differential habitat use a likely explanation (Monamy & Fox 2000). Nomadic movements, which allow individuals to locate to areas where vegetation density is optimal, appear to be a consistent pattern across a range of Dasyurid species. Nomadic movement patterns have been displayed by the Common Dunnart, Julia Creek Dunnart (Sminthopsis douglasi) and the Lesser Hairy-footed Dunnart (Sminthopsis youngsoni) with individuals utilising different resting sites over a period of days to weeks (Haythornthwaite & Dickman 2006; Monamy & Fox 2000; Righetti et al. 2000) Habitat Use and Home Range Size Limited radio tracking data has shown that a range of micro-habitats are selected for shelter during the day (Gates 2001). KI Dunnarts were found sheltering under Yaccas (Xanthorrhoea spp.) where the fronds are continuous to ground level, in leaf litter under Desert Banksias (Banksia ornata), in holes/burrows and inside a dead Yacca trunk. At the Kurralinga site there appeared to be a preference for sheltering under Yaccas, including ones that had succumbed to Phytophthora cinnamomi dieback. The dunnarts also spent periods of up to four hours using these shelters at night. The capture of dunnarts over a period of 11 and 18 years at multiple sites suggest that some areas provide core habitat, and dunnarts continually occupy such areas for relatively long periods of time (Gates 2001; Jones et al.