Antechinus subtropicus, Van Dyck & Crowther, 2000

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 : 318

37.

Subtropical Antechinus

Antechinus subtropicus

French: Antéchinus subtropical / German: Subtropische BreitfulRbeutelmaus / Spanish: Antequino subtropical

Taxonomy. Antechinus subtropicus Van Dyck & Crowther, 2000 ,

Emu Creek , 38 km E of Warwick (23° 13°03” S, 152° 24’ 54” F), Queensland, Australia.

The Subtropical Antechinus was initially identified as A. stuartii stuartii at the northern limit of its distribution. S. Van Dyck found A. subtropicus to be morphologically distinct and raised it to subspecies status under A. stuartii but, at the time, suspected it might need to be raised to full species status. Van Dyck and M. S. Crowther in 2000 raised it to full species status, noting that there was considerable overlap in distributions of both species in northern New South Wales and south-eastern Queensland. Molecular evidence later supported differences in morphology between the two species where they co-occur in the Border Ranges of north-eastern New South Wales. There were only shallow mitochondrial differences between the two species, suggesting recent divergence from common ancestry. The most recent genetic research, which has constructed phylogenies for all species of antechinus, indicated that A. subtropicus-A. stuartii are the youngest species pair in the genus. Monotypic.

Distribution. E Australia, from about Gympie in SE Queensland S to the Border Ranges and Dorrigo national parks in NE New South Wales.

Descriptive notes. Head-body 9.5-13.6 cm (males) and 8:1-11.2 cm (females), tail 8:8-10.6 cm (males) and 6:4.9-6 cm (females); weight 18-78 g (males) and 16-33-1 g (females). There is marked sexual dimorphism for size. The Subtropical Antechinus has no head-stripe, no impression of a dark head patch, and no distinct eye rings (although there may be pale dabs of eyeliner above and below eyes). It is most similar in terms of external coloring and skull morphology to the Brown Antechinus (A. stuartii ). The Subtropical Antechinus tends to be more uniformly brown from head to rump than the Brown Antechinus, which tends to be more grayish on head and neck, merging to brownish on rump, at least in the northern part of its distribution where the two species overlap. Nevertheless, these distinctions are very subtle and render the species essentially indistinguishable in the field. The Subtropical Antechinus tends to be heavier and longer than the Brown Antechinus and has a larger skull, with longer holes in the palate; however, these differences are not absolute; there is considerable overlap in all characters. All told, differences in skull morphology and external color between the Subtropical Antechinus and the Brown Antechinus are variable, which has caused considerable confusion as to their respective distributions. At present, genetics is key to determining relative distributions of the two species in south-eastern Queensland; there is some hope that with genetic hindsight, morphology of the pair may be reappraised and some more consistent field characters devised to separate the two.

Habitat. Essentially restricted to subtropical vine forests at elevations from near sea level to 1000 m (Lamington Plateau, 28° 16’ S, 153° 05’ E), preferring higher elevations in that range. It is abundant in major tracts of vine forest on or east of the Great Dividing Range south of Gympie (26° 11’ S, 152° 40’ E) to Brisbane (27° 28’ S, 153° 02" E), and perhaps more patchily south to the Queensland—-New South Wales border. Structural features of the typical complex notophyll vine forest inhabited by the Subtropical Antechinus include an abundance of notophylls and microphylls, lianas, vascular epiphytes, plant buttresses, compound entire leaves, and trunk-obscuring aroids such as Pothos . The uneven canopy of mixed evergreens and occasional deciduous trees emergent in such areas is 21-45 m high. The Subtropical Antechinus is rarely found in sclerophyll associations, where it generally limits itself to humid, dense areas such as fern gullies and vine entanglements along watercourses. It is particularly abundant in the perimeter vegetation of vine forests. It favors dense, tangled stands of invasive pioneer shrubs such as Lantana camara ( Verbenaceae ), wild raspberry Rubus spp. (Rosaceae) , bleeding heart Homalanthus spp. (Euphorbiaceae) , and bracken fern Pteridium esculentum. In one study on Mount Glorious (27° 20” S, 152° 47’ E, 40 km north-west of Brisbane), the Subtropical Antechinus avoided mature forest with sparse ground cover and disturbed areas with cunjevoi ( Alocasia macrorrhizos, Araceae ) and young palm growth. There was a greater preference for areas of tangled and fallen lianas and rotten logs. All areas where the Subtropical Antechinus occurs in south-eastern Queensland experience relatively high average annual rainfall of up to 2000 mm.

Food and Feeding. The Subtropical Antechinus hunts in dense rainforest understory of vine tangles and rotten logs for invertebrates (e.g. beetles, spiders, amphipods, and cockroaches) and probably small vertebrates. One large male Subtropical Antechinus in captivity promptly killed and ate adult House Mice ( Mus musculus); it will also consume carrion in the wild. The Subtropical Antechinus readily enters houses whereit scavenges meat scraps and pet food.

Breeding. Reproductive synchrony of the Subtropical Antechinus is achieved at any given site, but it can vary by several weeks across its small geographical distribution. All males die shortly after mating, and the majority of females die after their young become independent. On Mount Glorious, south-eastern Queensland, mating occurs only in September each year; this is followed immediately by the mortality of all males. Gestation lasts 25-26 days; births on Mount Glorious occur in October each year, after which young remain in the pouch for c¢.5 weeks and are weaned at c¢.3 months. Females have eight nipples, and they are often all occupied; litter size on Mount Glorious averages 7-5 young. In more northerly districts, mating occurs slightly earlier than on Mount Glorious. In the Conondale Range (26° 52° S, 152° 40’ E, ¢.70 km north of Brisbane), female Subtropical Antechinuses were captured on 21, 22, 24, and 25 October. All had pouches containing 7-8 young, each of which was 1.1-5 cm long. Their ages were thus c.12-20 days, their birth presumably having taken place early in October. Of 32 female specimens, representing localities over the entire distribution of the Subtropical Antechinus, all pouch areas contained eight nipples.

Activity patterns. There is no specific information for this species, but the Subtropical Antechinus is mostly nocturnal.

Movements, Home range and Social organization. Female Subtropical Antechinuses on Mount Glorious occupy home ranges of 0-32-0-47 ha; males most likely live in a much larger area. Male activity increases prior to the highly synchronized mating period in September.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Subtropical Antechinus appears to be common throughout much ofits limited distribution in Queensland and New South Wales. Nevertheless, it may not be common south of Brisbane (far south-eastern Queensland) or in New South Wales, where the Brown Antechinus may be found in higher density and broader distribution than previously thought. The most recent research suggests that a range of localities in north-eastern New South Wales and south-eastern Queensland that were assumed to support only Subtropical Antechinuses, may not. Only the Brown Antechinus has been captured in numerous regionsin the last few years from extensive trapping in Tamborine National Park, Main Range National Park, Girraween National Park in Queensland and various localities in and around the Border Ranges of north-eastern New South Wales. It is possible that Subtropical Antechinuses also occur in some of these locales but at much lower densities (and plausibly altitude) than Brown Antechinuses. Indeed, a current genetic study assessing supposed samples of Subtropical Antechinuses from south of Brisbane at a dozen locations have found thatall are in fact Brown Antechinuses. Subtropical Antechinuses have a habit of entering houses in areas such as Mount Glorious (west of Brisbane); this results in many deaths from domestic and feral cats, rat traps, and unfortunate drowning in toilet bowls and water tanks.

Bibliography. Baker et al. (2012), Braithwaite (1973), Burnett & Crowther (2008b), Crowther et al. (2003), Marlow (1961), Van Dyck (1982a, 1997), Van Dyck & Crowther (2000), Webb (1978), Wood (1970).

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. E Australia, from about Gympie in SE Queensland S to the Border Ranges and Dorrigo national parks in NE New South Wales.