Pseudantechinus macdonnellensis (Spencer, 1896)

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 : 295

11.

Fat-tailed Pseudantechinus

Pseudantechinus macdonnellensis

French: Dasyure a queue adipeuse / German: MacDonnell-Fettschwanz-Beutelmaus / Spanish: Falso antequino de cola gruesa

Other common names: Fat-tailed Antechinus, Fat-tailed False Antechinus

Taxonomy. Phascogale macdonnellensis Spencer, 1896 ,

south of Alice Springs, Northern Territory, Australia.

P. macdonnellensis takes its specific name from the MacDonnell Ranges, near Alice Springs, where it was first collected in 1894 on the Horn Scientific Expedition to central Australia; it was described as Phascologale macdonnellensis by W. B. Spencer two years later. There are currently six recognized species of “false antechinuses:” bilarni , macdonnellensis , mimulus , ningbing , roryi , and woolleyae , macdonnellensis , and mimulus were initially placed under Antechinus , along with Parantechinus apicalis . Nevertheless, G. H. H. Tate in 1947 erected a new genus ( Pseudantechinus ) for the false antechinuses, macdonnellensis and mimulus , and a monotypic genus for apicalis (Parantechinus) . In 1964, W. D. L. Ride, doubting the validity of Tate’s new genera, returned all three species to Antechinus . Later, P. A. Woolley examined penile morphology of Ride’s Antechinus supergroup and proposed that macdonnellensis , bilarni , the undescribed “ ningbing ,” and apicalis formed a distinct group. M. Archer subsequently resurrected both of Tate’s genera, assigning macdonnellensis and “ ningbing ” to Pseudantechinus , and both bilarni and apicalis to Parantechinus . Genetic work on Pseudantechinus has paralleled morphological research since P. R. Baverstock and colleagues used allozymes to confirm Tate’s contended genera Pseudantechinus and Parantechinus . Direct sequencing of mtDNA and nDNA has been conducted over the last decade. Consensus of this work is: monotypic genera containing Parantechinus apicalis and Dasykaluta rosamondae are discrete from each other and from the genus Pseudantechinus , P. bilarniis very different genetically from Parantechinus apicalis and all other species of Pseudantechinus ; and P. mimulus was recovered as sister to a clade containing P. macdonnellensis and P. roryi , but the latter two species were not reciprocally monophyletic, raising questions about their status. Monotypic.

Distribution. C Australia, including E Western Australia, C & S Northern Territory, N South Australia, and an isolated locality in far W Queensland.

Descriptive notes. Head-body 9.5-10.5 cm, tail 7.5-8.5 cm; weight 25-45 g (males) and 20-40 g (females). There is slight sexual dimorphism for size. Fur color of the Fat-tailed Pseudantechinus is grayish-brown above with chestnut patches behind ears; belly is grayish-white. Tail is tapering, usually very fat at base and distinctly shorter than head-body length, and accessory erectile tissue of males forms an appendage to the penis. This combination of characteristics serves to distinguish the Fat-tailed Pseudantechinus from all congeners except Rory’s Pseudantechinus (PF. rory:), to which the Fat-tailed Pseudantechinus is very similar.

Habitat. Mainly rocky hills and breakaways but also red sand plains (such as the Tanami Desert) where it nests inside termite mounds.

Food and Feeding. Generally speaking, insects form the main component of the diet of the Fat-tailed Pseudantechinus, but spiders,slaters (Isopoda), snails (Pulmonata), and even rodents may be eaten. Tail becomes very fat when food is plentiful. Ten insect orders and spiders ( Araneae ) were recorded in fecal samples from a population in West MacDonnell National Park, Northern Territory, during a 30month study; Isoptera, Coleoptera , and Orthoptera were the major insect ordersin the diet. A later study at the same site found some differences in prey items; there were three new classes and two new phyla in feces, including slaters, snails, and rodents. Specific identification of rodent hair in feces of Fat-tailed Pseudantechinuses was not possible, but the Central Australian Rock-rat ( Zyzomys pedunculatus ) was the common rodent at the site. Researchers speculated that the Fat-tailed Pseudantechinus might capture rodents or, given their small size, even feed on dead rodent carcasses.

Breeding. The Fat-tailed Pseudantechinus is monoestrous, with a highly seasonal reproductive pattern. Births occurred in September—October in a population studied in the West MacDonnell National Park. Maximum litter size (and teat number) is six; young depend on their mother for c.14 weeks. Sexual maturity is reached in the first year, and both sexes breed in more than one year. The male has an appendage on the penis (similar to that of Rory’s Pseudantechinus), the function of which is unknown.

Activity patterns. The Fat-tailed Pseudantechinus is predominantly nocturnal, but individuals are known to emerge from shelter among rocks to sun-bathe; indeed, Aborigines on occasion take advantage ofthis habit to catch them. One study assessed basking of the Fat-tailed Pseudantechinus in winter and found that they regularly foraged diurnally. Foraging bouts occurred throughout the day, but most bouts were observed within three hours of sunset. In comparison, basking occurred much more frequently in the morning. Basking and a shift toward diurnal foraging in winter were associated with a decrease in richness and abundance of predators. The Fat-tailed Pseudantechinus appears to compensate for occurrence of torpor on winter nights by changing its activity patterns and foraging during what is typically the rest phase.

Movements, Home range and Social organization. One study conducted at Ormiston Creek (Central Australia) found that male Fat-tailed Pseudantechinuses occupied larger home ranges (0-98-1-5 ha) than females (0-31-0-43 ha). Home ranges overlapped little within a sex, but home ranges of males overlapped those of females by on average 38%. Anotherstudy at the samesite showed home range sizes that were 15-5-24-5 times larger than the previous study, but home range lengths of individuals were similar. The Fat-tailed Pseudantechinus appears to undergo fewer long-range movements than might be expected for an arid-zone dasyurid. This may be due to relatively high, stable resources (such as insect prey) in their favored rocky habitat.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Fattailed Pseudantechinus has a wide distribution and presumably a large overall population, and it occurs in a number of protected areas. It does not face any current major conservation threats. Habitats where the Fat-tailed Pseudantechinus occurs are rugged and not affected by European Rabbits (Oryctolagus cuniculus) or pastoralism. Domestic and feral cats may be a threat to some local populations.

Bibliography. Archer (1982c), Baverstock et al. (1982), Burwell et al. (2005), Cooper, N.K. et al. (2000), Edwards (2013), Gilfillan (2001a, 2001b), Kitchener (1991), Kitchener & Caputi (1988), Krajewski & Westerman (2003), Pavey & Geiser (2008), Pavey et al. (2003), Ride (1964), Spencer (1895a, 1895b, 1896b), Tate (1947), Westerman et al. (2007), Woinarski, Burbidge, van Weenen & Dickman (2008), Woolley (1991b, 2008h).

Figures

On following pages: 29. Black-tailed Antechinus (Antechinus arktos); 30. Fawn Antechinus (Antechinus bellus); 31. Yellow-footed Antechinus (Antechinus flavipes), 32. Atherton Antechinus (Antechinus godmani); 33. Cinnamon Antechinus (Antechinus leo); 34. Swamp Antechinus (Antechinus minimus); 35. Buff-footed Antechinus (Antechinus mysticus); 36. Brown Antechinus (Antechinus stuartil); 37. Subtropical Antechinus (Antechinus subtropicus); 38. Dusky Antechinus (Antechinus swainsonii).

Distribution. C Australia, including E Western Australia, C & S Northern Territory, N South Australia, and an isolated locality in far W Queensland.