Sminthopsis douglasi, Archer, 1979

Russell A. Mittermeier & Don E. Wilson, 2015, Dasyuridae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 232-348 : 339-340

62.

Julia Creek Dunnart

Sminthopsis douglasi

French: Dunnart de Julia Creek / German: Douglas-SchmalfuRbeutelmaus / Spanish: Raton marsupial de Douglas

Taxonomy. Sminthopsis douglasi Archer, 1979 ,

Julia Creek (20° 40’ S, 141° 40” E), Cloncurry River Watershed , Queensland, Australia.

Sminthopsis is the most speciose genus (currently 19 species) of living dasyurid marsupials and, along with its close relatives Antechinomys (one species), Ningaui (three species), and Planigale (five species) constitutes the clade Sminthopsinae . This group has been the subject of considerable morphological and molecular investigation. A recent genetic phylogeny (several mitochondrial and nuclear genes) failed to support monophyly of the genus Sminthopsis with respect to Antechinomys and Ningaui . There were three deeply divergent clades of Sminthopsis . In the first, S. longicaudata was sister to A. laniger . In the second, there was the traditional morphologically based Macroura Group: five Sminthopsis comprised a strongly supported clade including S. crassicaudata, S. bindi , S. macroura , S. douglasi , and S. virginiae . This clade offive dunnarts was a poorly supported sister to the three species of Ningaui (N. rider, N. timealeyi , and N. yvonneae). The combined clade of five Sminthopsis and three Ningaui was positioned as a poorly supported sister to a well-supported third clade containing the remaining species of Sminthopsis (13 species comprising the Murina Group). In the course of revising the Sminthopsis, M. Archer noted two distinct but unnamed species, which he named S. butler : from Cape York, Queensland, and S. douglasi , the latter based on specimens collected from north-central Queensland by M. Browne in the 1930s. In his description of 1979, Archer noted that E. Le G. Troughton in 1965 had referred some specimens to S. lumholtzi (today, S. virginiae ), but Archer repositioned these as part of his S. douglas: group, which are notably larger than S. virginiae . Genetically and morphologically, S. douglas: is best positioned as sister to S. virginiae . In the latest (2012) genetic phylogenies, the pair of S. douglasiand S. virginiaeis a well-supported sister of S. macroura (S. douglasi and S. macroura co-occur in some areas). Monotypic.

Distribution. NE Australia, across the grassy downs country between Julia Creek and Richmond of NW Queensland.

Descriptive notes. Head-body 13-13.5 cm (males) and 11-12.5 cm (females), tail 12-13 cm (males) and 11-12 cm (females); weight 50-70 g (males) and 40-60 g (females). There is subtle sexual dimorphism for size. Julia Creek Dunnarts are brown and speckled with gray above and buffy white below. There is a distinct face-stripe, and dark hairs in ring around eyes, at tail tip, and on outer middle edge of ears. There are rufous hairs on cheeks and at base of ears. Fattened, tapering tail is slightly shorter than head-body length. The Julia Creek Dunnartis the largest species of Sminthopsis , distinguished from all congeners by size. It shares many cranial, dental, and external characters with the Red-cheeked Dunnart (S. virginiae ), but it is larger and differs in having a stouter tail. Like the Stripe-faced Dunnart (S. macroura ), the Julia Creek Dunnart has a prominent facial stripe and, when in good condition, a long tail that is fattened at base. When it is fully grown, the Julia Creek Dunnart is larger than the Stripe-faced Dunnart, and even recently weaned young are readily distinguished by length of their hindfeet (more than 20 mm).

Habitat. Mitchell Grass downs, covered with cracking clay soils. The Julia Creek Dunnart uses cracks and dense vegetation (particularly annual flinders grass, Iseilema spp. , Poaceae ) as cover from predators. In the wet season (October-March) when cracks in the ground may close up, Julia Creek Dunnarts presumably shelter under vegetation. On the downs, this consists largely of tussocks of perennial Mitchell grasses ( Astrebla spp. , Poaceae ) and flinders grass; perennial and annual forbs grow between them.

Food and Feeding. There is no specific information available for this species, but the Julia Creek Dunnart probably feeds on a wide variety of insects and other arthropods.

Breeding. Breeding season of the Julia Creek Dunnart extends from September to February. Females may have as many as two litters of up to eight young in a season. Female Julia Creek Dunnarts mature more rapidly than males. In the wild, individuals can possibly breed in the season in which they were born; both sexes may breed in a second season and some females in a third.

Activity patterns. The Julia Creek Dunnart is nocturnal. During the day, they rest in a maze of underground cavities provided by grass-covered, cracking clay soils in their distribution. Such areas are also known to provide shelter for rodents such as the Australian Long-haired Rat ( Rattus villosissimus) and Forrest's Leggadina ( Leggadina forresti ) and other dasyurids such as the Stripe-faced Dunnart (S. macroura ), the Fat-tailed Dunnart (S. crassicaudata ), and the Long-tailed Planigale ( Planigale ingrama).

Movements, Home range and Social organization. Male Julia Creek Dunnarts are generally more mobile and have larger home ranges (up to 7-1 ha) than females; otherwise, little is known about social organization.

Status and Conservation. Classified as Near Threatened on The IUCN Red List. Listed as endangered in Australia. The Julia Creek Dunnart is known from a relatively large area, but it is sparsely distributed within its distribution, and little is known about its population dynamics. Prior to 1992, the Julia Creek Dunnart was known from just four specimens collected on grazing properties on grassy downs between the towns ofJulia Creek and Richmond in north-western Queensland. As a result of trapping and identification of remains in owl pellets and stomachs of Red Fox (Vulpes vulpes) and domestic and feral cats, the Julia Creek Dunnart is now known to inhabit a much larger area of downs country in Queensland. The Julia Creek Dunnart almost qualifies as Threatened under [IUCN’s Criterion A or B2. Exotic predators (especially domestic and feral cats and Red Fox), grazing by domestic sheep and cattle, and presence of prickly acacia ( Acacia nilotica, Fabaceae ) have been implicated as major threats to the Julia Creek Dunnart. Cats, in particular, prey heavily on Julia Creek Dunnarts; in one field study carried out at night on properties in the vicinity ofJulia Creek, Queensland, cats were spotlighted and shot from vehicles with a rifle. In subsequent analysis of cats’ digestive tracts, 18 Julia Creek Dunnarts were retrieved from 187 cat samples during a threeyear period; frequency of occurrence ofJulia Creek Dunnarts in gut contents was 6%. Experiments eliminating grazing by sheep had little effect on the Julia Creek Dunnart, but there were questions raised about methods used in the study. Effects of cattle grazing are unknown. One study used computer modeling to predict suitable habitat for the Julia Creek Dunnart. Within the known habitat range of the Julia Creek Dunnart, most of the area was predicted to have low suitability, with similar findings from the field survey. Notable exceptions were in national parks (particularly Bladensburg National Park), road reserves, stock routes, and Toorak research station. Such areas are subject to low grazing pressure from domestic stock and generally have a low density of prickly acacia and stock-watering points. Ground cover and grazing pressure were the most influential factors on habitat suitability for Julia Creek Dunnarts; dominant soil type, rainfall, and prickly acacia density were the most influential environmental variables. Results suggested that maintaining areas of good ground cover on clay soil with low prickly acacia density is crucial forJulia Creek Dunnart conservation and recovery. A recovery plan was developed for the 2000-2004 period; an updated plan is being drafted. Recommendations from the current recovery plan include surveys to improve knowledge of current distribution and critical habitat, studying ecology and habitat requirements, managing threats at key sites, developing management agreements with private landowners to benefit the Julia Creek Dunnart because it occurs on private land, and promoting community support and participation in the recovery activities.

Bibliography. Archer (1979, 1981a), Baverstock et al. (1984), Blacket, Adams et al. (2001), Blacket, Cooper et al. (2006), Burnett & Winter (2008e), Hume et al. (2000), Krajewski et al. (2012), Kutt (2003), Lundie-Jenkins & Payne (2000), Mifsud & Woolley (2012), Smith, C.S. et al. (2007), Thomas (1888b), Throughton (1965b), Woolley (1992, 2008), Woolley et al. (2002).

Figures

56. Kangaroo Island Dunnart (Sminthopsis aitken), 57. Chestnut Dunnart (Sminthopsis archer), 58. Kakadu Dunnart (Sminthopsis bindi), 59. Butler's Dunnart (Sminthopsis butleri), 60. Fat-tailed Dunnart (Smunthopsis crassicaudata), 61. Little Long-tailed Dunnart (Sminthopsis dolichura), 62. Julia Creek Dunnart (Smunthopsis douglasi), 63. Gilbert's Dunnart (Sminthopsis gilbert), 64. White-tailed Dunnart (Sminthopsis granulipes), 65. Grey-bellied Dunnart (Sminthopsis griseoventer), 66. Greater Hairy-footed Dunnart (Smunthopsis hirtipes), 67. White-footed Dunnart (Sminthopsis leucopus), 68. Greater Long-tailed Dunnart (Sminthopsis longicaudata), 69. Stripe-faced Dunnart (Sminthopsis macroura), 70. Common Dunnart (Sminthopsis murina), 71. Ooldea Dunnart (Sminthopsis ooldea), 72. Sandhill Dunnart (Sminthopsis psammophila), 73. Red-cheeked Dunnart (Sminthopsis virginiae), 74. Lesser Hairy-footed Dunnart (Sminthopsis youngsoni)

Distribution. NE Australia, across the grassy downs country between Julia Creek and Richmond of NW Queensland.