Planigale maculata (Gould, 1851)

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 : 328-329

49.

Common Planigale

Planigale maculata

French: Planigale commun / German: Gefleckte Flachkopfbeutelmaus / Spanish: Planigalo pigmeo

Other common names: Pygmy Planigale

Taxonomy. Antechinus maculatus Gould, 1851 ,

Clarence River, New South Wales, Australia.

E. Le G. Troughton erected the genus Planigale in 1928 to accommodate three species of minute, flat-headed dasyurids known from Australia at that time. In 1976, M. Archer conducted an impressive revision of the genus Planigale , and in 1982, Archer suggested that P maculata and the closely related P. novaeguineae have skulls that are not as flattened as in other species of Planigale , suggesting they may represent an early branch of Planigale radiation. Indeed, the species plausibly differentiated from each other as recently as 11,000 years ago when Torres Strait flooded. Various genetic studies have been conducted on the genus Planigale since the early 1980s. The genus was placed in its own subfamily because it shared no morphological features allying it unequivocally with other dasyurids. Nevertheless, Planigale was later incorporated within a distinct tribe, the Planigalini, as a member of the subfamily Sminthopsinae , along with three other dasyurid genera ( Sminthopsis , Antechinomys , and Ningau) based on genetic (allozyme) and serological evidence. DNA sequencing has since corroborated the close genetic relationship of these four genera. Monophyly of Planigale has been well established genetically, but taxonomy within the genus is under revision, in particular in Western Australia ( Pilbara ), Kimberley, and Northern Territory, where there are likely several new species residing within the P. maculata complex. The present subspecies will likely be revised when the new species from Barrow Island, Western Australia is raised, as part of a broader revision of the group. Two subspecies recognized.

Subspecies and Distribution.

P.m.maculataGould,1851—EAustralia,NQueensland(CapeYork),SthroughoutEQueenslandtoENewSouthWales(Gosford),alsoinFraserandBribieIs.

P.m. sinualis Thomas, 1926 — N Australia, N Western Australia, N Northern Territory (Top End and Groote Eylandt I).

Individuals from Barrow I, N Western Australia, are included here but possibly represent a differentstill undescribed species.

Descriptive notes. Head-body 5.2-8.4 cm (males) and 6.8-3 cm (females), tail 4-8— 6-4 cm (males) and 4.6-6.5 cm (females); weight 4-16-3 g (males) and 3-5-17-2 g (females) for P. m. sinualis. The Common Planigale is mildly sexually dimorphic for size and can be distinguished from other small carnivorous marsupials byits small size, short (less than 11 mm) and relatively broad hindfeet (with a length-to-width ratio of less than four), three upper and three lower premolar teeth, pale-colored claws, and relatively conical head (crown depth greater than 5 mm). Despite its specific epithet, maculata , which means spotted, the normally cinnamon-washed gray coat of the Common Planigale is only rarely spotted.

Habitat. Nearly all terrestrial habitats, including cool mountain rainforests, steaming monsoonal floodplains, and weed-infested urban reserves.

Food and Feeding. The Common Planigale forages on the ground among leaf-litter, in dense grass, and in low vegetation. It is a capable predator, subduing its prey by repeatedly and remorselessly attacking the back of the head until it is either killed or disabled. In captivity, Common Planigales thrive on carrion and readily consume moths, phasmids, grasshoppers, spiders, and small skinks.

Breeding. Common Planigales build a spherical nest of thin-bladed grasses in which they raise as many as ten young in eastern and north-eastern Australia, or twelve young in the Top End. Young stay together in the maternal nest until they weigh c.6 g; individuals larger than this nest alone. In eastern Australia, most breeding occurs during spring and summer. A study on the subspecies sinualis from the Top End found that it bred all months of the year and teat number in females was 8-13. Sizes of 21 litters varied from four to twelve young, with an average of eight young. Two records of ovulation rate exceeded number ofteats, which in turn was typically greater than number of pouch young. Seminiferous tubules of males were large, which is typical of dasyurids.

Activity patterns. The Common Planigale has been found sheltering by day under rocks, fallen timber, and bark and in termite mounds. It is also known to use human debris, including railway sleepers and sheet iron, as shelter.

Movements, Home range and Social organization. There is no information available for this species.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Museum records show that domestic and feral cats and domestic dogs kill many Common Planigales; many also die of misadventure by drowning in swimming pools and falling into construction holes. Their remains have been found in feces of Northern Quolls ( Dasyurus hallucatus ), pellets of common barn owls (7yto alba), and stomachs of cane toads (Rhinella marina). Their wide distribution, ability to tolerate disturbed habitats, and high densities in many sites suggest that populations of Common Planigales are not threatened. One study found that Common Planigales rapidly learned to avoid toxic cane toads. Although 90% of naive Common Planigales attacked cane toads, 83% of them survived because they either rejected the toad unharmed, or killed and consumed it snout-first, thereby largely avoiding the toad’s toxic parotid glands. Most Common Planigales learned from a single encounter and thereafter refused to attack cane toads for long periods (up to 28 days). Toad-exposed Common Planigales also avoided native frogs for up to nine days, thereby providing an immediate benefit to native anuran populations. However, Common Planigales gradually learned to use chemical cues to discriminate between frogs and toads. Thus,itis clear that generalist predators such as Common Planigales can rapidly learn to distinguish and avoid novel toxic prey. Interestingly, the authors concluded that it might be feasible to teach especially vulnerable predators to avoid cane toads before the toads invade, by using low-toxicity, taste-averse baits. A subsequent study examined responses of Common Planigales to cane toads in north-eastern Queensland, where the two species have been sympatric for more than 60 years. This research found that unlike their toad-naive conspecifics from the Northern Territory, Common Planigales in Queensland survived ingestion of toad tissue without ill effects and continued to attack toads in a substantial proportion of subsequenttrials. The study suggested that physiological tolerance to toad toxins might be higher in Common Planigales after many decades (c.60 generations) of exposure to this toxic prey.

Bibliography. Archer (1976a, 1982c), Aslin (1975), Baverstock et al. (1982), Blacket et al. (2000), Burnett (2008b), Burnett & Dickman (2008b), Gould (1851), Krajewski, Blacket et al. (1997), Krajewski, Young et al. (1997), Llewelyn et al. (2010), Painter et al. (1995), Taylor et al. (1982), Troughton (1928), Van Dyck (1979a), Webb, J.K. et al. (2008).

Figures

On following pages: 41. Short-furred Dasyure (Murexia longicaudata); 42. Broad-striped Dasyure (Murexia rothschildi); 43. Long-nosed Dasyure (Murexia naso); 44. Red-tailed Phascogale (Phascogale calura); 45. Northern Brush-tailed Phascogale (Phascogale pirata); 46. Common Brush-tailed Phascogale (Phascogale tapoatafa); 47. Giles's Planigale (Planigale giles); 48. Long-tailed Planigale (Planigale ingrami); 49. Common Planigale (Planigale maculata); 50. Papuan Planigale (Planigale novaeguineae); 51. Narrow-nosed Planigale (Planigale tenuirostris); 52. Wongai Ningaui (Ningauiride); 53. Pilbara Ningaui (Ningaui timealeyi); 54. Southern Ningaui (Ningaui yvonneae); 55. Kultarr (Antechinomys laniger).

Subspecies and Distribution. P.m.maculataGould,1851—EAustralia,NQueensland(CapeYork),SthroughoutEQueenslandtoENewSouthWales(Gosford),alsoinFraserandBribieIs. P.m. sinualis Thomas, 1926 — N Australia, N Western Australia, N Northern Territory (Top End and Groote Eylandt I). Individuals from Barrow I, N Western Australia, are included here but possibly represent a differentstill undescribed species.