Dasycercus blythi (Waite, 1904)

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 : 289-290

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Brush-tailed Mulgara

Dasycercus blythi

French: Mulgara a queue touffue / German: Pinselschwanz-Beutelmaus / Spanish: Mulgara de cola de cepillo

Other common names: Hillier's Mulgara

Taxonomy. Phascogale blythi Waite, 1904,

Pilbarra District, North Western Australia, Australia.

T. Iredale and E. Le G. Troughton reduced the three previously described forms of Dasycercus ( cristicauda , blythi , and hillieri) to two species, D. cristicauda and D. blythi, they considered hillier: to be a synonymy of D. enisticauda. In 1970, W. D. L. Ride referred to a single species, D. cristicauda , and in 1988 J. A. Mahoney and Ride formally synonymized the three nominal species with D. cristicauda . Subsequently, two genetically distinct forms of Dasycercus were found; these were referred to as D. cristicauda and D. hillieri. Nevertheless, P. A. Woolley later repositioned these as D. cristicauda and D. blythi. Since then, molecular studies, using mtDNA and nDNA, have confirmed distinct divergence between these two species; they were well resolved and phylogenetically positioned as sisters; the two Dasycercus in turn were clearly resolved as sister to Dasyuroides byrnei . A suite of ecological studies was conducted on Dasycercus from 1980 to 2003. These were thought to be on D. cristicauda , but it has been confirmed that they were misidentified: the animals under study were actually D. blythi . Monotypic.

Distribution. Australia, mainly in C Western Australia and S Northern Territory, but also severalisolated locations in N South Australia and W Queensland.

Descriptive notes. Head-body 13.5-16.5 cm (males) and 12-14 cm (females), tail 7-5—-10 cm (males) and 6-9 cm (females); weight 75-110 g (males) and 60-90 g (females). There is modest sexual dimorphism in size. Brush-tailed Mulgaras are pale sandy brown above, grayish-white below. Hairs are reddish on base oftail and black on distal two-thirds. Black hairs do not form a dorsal crest. Ears are short and rounded. There are five toes on forefeet and hindfeet. The Brush-tailed Mulgara could be confused with its sister taxon, the Crest-tailed Mulgara (D. eristicauda); tail morphology is the best way to tell them apart. Both species have hairy, black-tipped tails: the Brushtailed Mulgara has an evenly furred, brushy tail, whereas hairs on dorsal surface oftails of Crest-tailed Mulgara are long and form a fin-like crest. The Crest-tailed Mulgara is also generally more brightly (rufous) colored than the Brush-tailed Mulgara. Number of premolar teeth used to be thought a discriminating character, but recent work has shown that it is inconsistent between the species. In females, nipple numbers are different: six in the Brush-tailed Mulgara and eight in the Crest-tailed Mulgara. This character, however,is rarely useful as a diagnostic because unless females are heavily pregnant or have given birth, nipples are rarely visible. Furthermore, if the pouch is not full, unused nipples quickly regress to pre-birth condition and are very difficult to see.

Habitat. Arid zone across central Australia in spinifex (7riodia, Poaceae ) grasslands, sand plains, and gibber plains (rocky, pebble-littered desert pavement) across central Australia. The Brush-tailed Mulgara lives in burrows that it digs on flats between low sand dunes. Near Uluru (formerly Ayer’s Rock), burrows excavated in September contained only one entrance with 2-3 side tunnels and pop-holes; a single female with pouch young occupied each burrow. In the Tanami Desert, one excavated burrow had more tunnels. In one study of Brush-tailed Mulgaras in central Australia, capture locations consisted of a sand plain, a gibber plain, and a sand ridge. The sand-plain site comprised a slight rise of coarse-grained, non-mobile sand and a small area of poorly developed low dune. No hummock grasses were present; instead, tussock grasses in the Poaceae family ( Aristida holathera , A. contorta, and Eriachne aristidea, among others) dominated the ground stratum. On average at this site, tussock grass cover exceeded 10%. Forbs and subshrubs were comparatively unimportant in terms of cover and frequency. Two long-lived species of Acacia (Fabaceae) , A. brachystachya and A. kempeana, dominated the upper stratum, but neither species individually exceeded 5% cover. Overall, the site mostly lacked species characteristic of deep, mobile sands. The two gibber-plain sites were characterized by high cover of surface sand (average 23%), including numerous raised mounds that could potentially serve as burrow sites. Neither site supported hummock grasses; rather, they were characterized by dominant tussock grasses, with nine of the 15 diagnostic species belonging to this functional group. Tussock species most characteristic of the sites were A. contorta, Tragus australianus , Enneapogon avenaceus , and Dactyloctenium radulans .

Food and Feeding. The Brush-tailed Mulgara hunts at night, and when food is plentiful, fat is stored in the tail as a reserve. In one study from the Great Sandy Desert, it took a wide variety of prey, including vertebrates (mammals, reptiles, birds), seven insect orders (including beetles, bugs, grasshoppers, and ants), spiders, and centipedes. Mammals included carnivorous marsupials ( Dasyuridae ) and rodents ( Muridae ); reptiles included dragons ( Agamidae ), skinks ( Scincidae ), and monitors ( Varanidae ). Bird species were not identified. In another study, insects, arachnids, and rodents were the main prey taken by Brush-tailed Mulgaras; however, reptiles, centipedes, and small marsupials were also consumed. Insects represented 92% by percent frequency of occurrence in feces, and rodents represented 33% by percent frequency. Invertebrate prey 3-6 mm in length and vertebrate prey also occurred frequently in feces, but smaller prey items (1-5 mm), when present, occurred in large numbers. Importance of different types of prey to the diet of the Brush-tailed Mulgara is as follows: Insecta, Arachnida, Rodentia, Chilopoda , Reptilia, Marsupialia, Amphibia, and Aves. Up to 14 orders ofinsects have been found in feces of Brush-tailed Mulgaras. Sixty-two percent of Brush-tailed Mulgaras captured had fed on coleopterans, 33% on hymenopterans, 25% on blattodeans, 21% on orthopterans, 15% on lepidopterans, 10% on isopterans, and less than 10% on other orders. Coleopteran families identified included Carabidae , Curculionidae , Chrysomelidae , Elateridae , Scarabaeidae , and Tenebrionidae . Hymenopterans were represented primarily by ants (30% of feces), with up to 13 individuals occurring per fecal sample, whereas Isopterans occurred in only 10% offeces but were represented by as many as 60 individuals per feces. In this study, five feces (10%) contained remains of larvae, including mainly Coleoptera and Lepidoptera compared with 48 feces (92%) that contained remains of adult insects. Of vertebrate prey, rodents were most frequently eaten, accounting for 33% by frequency. Prey species included the House Mouse ( Mus musculus ), the Australian Long-haired Rat ( Rattus villosissimus ), the Spinifex Hopping Mouse ( Notomys alexis ), native mice ( Pseudomys ), the Wongai Ningaui ( Ningaui ridei ), and dunnarts ( Sminthopsis ). Reptile prey (21% by frequency) included geckos, skinks, dragons, and pygopodids. Aves and Amphibia were eaten infrequently. It was discovered that Brush-tailed Mulgaras ate more individual prey items in winter and spring than autumn and also more largesized prey in spring than autumn. In autumn, they consumed mostly insects (100% by frequency) and few rodents (8%), but in winter and spring, they switched to more rodents (38% and 47%, respectively) and insects (88% and 93%, respectively). Such seasonal shifts in diet were hypothesized to reflect changes in availability of different groups of prey, or changes in prey selectivity by Brush-tailed Mulgaras in response to costs imposed by seasonal reproduction.

Breeding. Little is known about breeding habits of Brush-tailed Mulgaras. In central Australia, females with up to six young in the pouch have been captured in September. Among captive individuals, mating has been observed from mid-May to mid-June, and young have been born in late June, July, and August, following gestation of 5-6 weeks. Young suckle for 3-4 months and become reproductively mature when they are 10-11 months old. Individuals of both sexes have been known to enter breeding condition each year forsix years, suggesting that they are fairly long-lived. If Brush-tailed Mulgaras continue to grow throughoutlife, as appears to be the case from examination of their bones, variation observed in size of adult specimens may be in part a reflection of age. A recent study from central Australia showed that females had 1 litter/year, with a median and maximum litter size of six; births in the Tanami occurred in July, at least a month earlier than they did at Uluru. Another study from the western Simpson Desert suggested a flexible breeding period for Brush-tailed Mulgaras. One pregnant female was found in June and another with pouch young in September, both of which fit the pattern of other studies, with births in June to September/October and lactating females andjuveniles present in October-December. Nevertheless, researchers also captured lactating females in February and observed independentjuveniles in April-May, suggesting that females can give birth as late as December orJanuary in some areas.

Activity patterns. The Brush-tailed Mulgara is not strictly nocturnal. It has been known to sun-bathe at the burrow entrance; captive individuals will emerge from cover during the day to stretch out under an infrared lamp. If two or more captive Brush-tailed Mulgaras are housed together, they regularly lie with their heads on each other’s backs.

Movements, Home range and Social organization. A study from central Australia demonstrated that Brush-tailed Mulgaras were generally solitary; males and females were found in the same burrow only during the mating season. Tolerance displayed in captivity to other individuals may not be exhibited under natural conditions. Individuals may use several burrows in their home range. Another more recent study in central Australia indicated that the population fluctuated annually, declining during the breeding season (June—October) and increasing again following the influx ofjuveniles in spring. Bodyweights and tail widths of captured individuals peaked before breeding and then declined until spring; individuals retained better body condition in a Tanami than at an Uluru population. In both regions, individuals were resident for 1-2 years; daughters remained near their mother’s home range, but males moved to other areas.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Not listed in Australia, although it was formerly listed as vulnerable under D. cristicauda . From historical records, the Brush-tailed Mulgara was one of the most common mammals encountered along the Western Australian Canning Stock Route in the 1900s, from Wiluna to Hall’s Creek. It is broadly distributed across Australia’s inland arid zone and is probably common. A recent study in central Australia concluded that persistence of Brush-tailed Mulgaras in central Australia is most likely a result of the following: flexibility in use of food resources, ability to enter torpor and tolerate large declines in bodyweight and condition, and propensity to dig deep burrows. Such attributes presumably buffer Brush-tailed Mulgaras from climatic and resource uncertainties characteristic of arid Australia and impacts of predators such as domestic and feral cats (Felis catus) and the Red Fox (Vulpes vulpes). These introduced predators have contributed to decline or extinction of numerous other medium-sized Australian marsupials. Indigenous people may have had an impact on the Brush-tailed Mulgara in the past; Aboriginal women are adept at digging them up from burrows. Indeed, as recently as 1966, Brush-tailed Mulgaras were collected and eaten at one locality in the Northern Territory.

Bibliography. Adams et al. (2000), Iredale & Troughton (1934), Lee et al. (1982), Mahoney & Ride (1988b), Masters & Dickman (2012), Masters et al. (2003), Pavey, Burwell et al. (2009), Pavey, Nano et al. (2011), Ride (1970a), Westerman et al. (2007), Woolley (1971a, 1990a, 2005a, 2006, 2008b), Woolley et al. (2013).

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. Australia, mainly in C Western Australia and S Northern Territory, but also severalisolated locations in N South Australia and W Queensland.