Antechinus adustus (Thomas, 1923)

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 : 309

26.

Rusty Antechinus

Antechinus adustus

French: Antéchinus rouilleux / German: Rostfarbene BreitfulRbeutelmaus / Spanish: Antequino herrumbroso

Other common names: Tropical Antechinus

Taxonomy. Phascogale flavipes adusta Thomas, 1923 ,

Dinner Creek , now Charmilan Creek (17° 42’ S, 145° 31’ E), 885 m, near Ravenshoe, Queensland, Australia.

For many decades, until its reassessment in 2000, this species was placed as a subspecies within the A. stuartii species complex of eastern Australia. Morphological work showed A. adustus to be distinctly different in external body color and various features of the skull anatomy from A. stuarti. Further research in 2012 exploring systematics of the entire genus Antechinus recovered genetic data further confirming that these two species are distinct. Monotypic.

Distribution. NE Queensland, between Mt Windsor Tableland and the Bluewater Range. This distribution spans ¢.325 km N-S and is less than 20 km wide for most ofits length.

Descriptive notes. Head-body 9.4-12.5 cm (males) and 8:8-10.9 cm (females), tail 9.1-10.4 cm (males) and 7.2-10.1 cm (females); weight 28-42 ¢g (males) and 18-35 g (females). There is marked sexual dimorphism in size. The Rusty Antechinus has longer and darker fur and darker bare parts than the Brown Antechinus (A. stuart), the Subtropical Antechinus ( A. subtropicus ), the Bufffooted Antechinus ( A. mysticus ), and the Yellow-footed Antechinus ( A. flavipes ). Fur on back of the Rusty Antechinusis uniformly dark brown with rusty tips; there is no eye ring as in the Yellow-footed Antechinus and no reddish color to cheeks as in the Atherton Antechinus ( A. godmani ), which share parts of its geographical distribution.

Habitat. Relatively cool, wet, undisturbed rainforests at elevations above 600 m. The Rusty Antechinuses prefers an abundance of tree hollows, which it uses for shelter, sometimes with several individuals sharing a hollow. Hollows are typically located in midto upperstrata of the forest and are lined with leaflitter, lichens, and moss.

Food and Feeding. The Rusty Antechinus forages from ground level into the tree canopy for moths, beetles, spiders, cockroaches, flies, worms, and even small vertebrates, including frogs and skinks. It also consumes carrion.

Breeding. Rusty Antechinuses follow the typical antechinus reproductive pattern where increased activity in both sexes signifies onset of highly synchronized breeding, which concludes with death of all males in a population. Across the distribution of the Rusty Antechinus, mating is from late May to July, and thus births occur from late June to August. Nevertheless, at any given site, mating and births occur across a shorter 2-3 week period. An average of 4-2 young is raised in the pouch, which contains six nipples. Young are weaned in December—January, in time for peak insect abundance and coinciding with increased temperature and moisture at that time ofyear.

Activity patterns. The Rusty Antechinus is unusual in being active mostly during the day, and it is noteworthy that they share parts of their distribution with two larger species of antechinuses, the Atherton Antechinus ( A. godmani ) and Yellow-footed Antechinus.

Movements, Home range and Social organization. The Rusty Antechinus typically has a home range of 1-2 ha. Because there is annual die-off of males, most male-female interactions are concentrated around the short and intense breeding period.

Status and Conservation. Classified as Least Concern on The [UCNRed List. Despite having a small distribution, the high density of the Rusty Antechinus throughout a largely protected distribution suggests its immediate status is secure. Nevertheless, Rusty Antechinuses depend on high-elevation rainforest, so warming and drying anticipated in the Wet Tropics over the next 30 years associated with global warming may threaten its long-term security. Lesser sooty-owls (7yto multipunctata), moreporks (Ninox novaeseelandiae), and domestic and feral cats are known to prey on the Rusty Antechinus. Analysis of regurgitated pellets from roosting sites of lesser sooty owls indicates that the Rusty Antechinus is only a rare component of the owl’s diet, particularly compared with its congener, the Atherton Antechinus. Both species of antechinuses are found in similar numbers where they co-occur, so the largely diurnal activity pattern of Rusty Antechinuses probably explains why nocturnal predators only rarely capture them.

Bibliography. Burnett & Crowther (2008a), Van Dyck & Crowther (2000), Watt (1991).

Figures

On following pages: 2. Crest-tailed Mulgara (Dasycercus cristicauda); 3. Kowari (Dasyuroides byrnei); 4. Kaluta (Dasykaluta rosamondae); 5. Dibbler (Parantechinus apicalis); 6. Woolley's Three-striped Dasyure (Myoictis leucura); 7. Miller's Three-striped Dasyure (Myoictis melas); 8. Wallace's Three-striped Dasyure (Myoictis wallacii); 9. Tate's Three-striped Dasyure (Myoictis wavicus); 10. Sandstone Pseudantechinus (Pseudantechinus bilarni); 11. Fat-tailed Pseudantechinus (Pseudantechinus macdonnellensis); 12. Carpentarian Pseudantechinus (Pseudantechinus mimulus); 13. Ningbing Pseudantechinus (Pseudantechinus ningbing); 14. Rory’s Pseudantechinus (Pseudantechinus roryi); 15. Woolley's Pseudantechinus (Pseudantechinus woolleyae); 16. Speckled Dasyure (Neophascogale lorentzii); 17. Red-bellied Phascogale (Phascolosorex doriae); 18. Narrow-striped Dasyure (Phascolosorex dorsalis).

Distribution. NE Queensland, between Mt Windsor Tableland and the Bluewater Range. This distribution spans ¢.325 km N-S and is less than 20 km wide for most ofits length.