Notoryctes typhlops, Stirling, 1889

Russell A. Mittermeier & Don E. Wilson, 2015, Notoryctidae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 210-219 : 219

2 .

Central Desert Marsupial Mole

Notoryctes typhlops

French: Itjari-itjari / German: GrofRRer Beutelmull / Spanish: Topo marsupial meridional

Other common names: Central Marsupial Mole, Itjaritjari, Southern Marsupial Mole

Taxonomy. Psammoryctes typhlops Stirling, 1889 ,

“ Indracowie Cattle Station ... about 100 miles from the Charlotte Waters Telegraph Station,” central Australia.

In 1888, E. C. Stirling announced the discovery of a peculiar new animal from Central Australia and gave a brief description. The following year he provided an extended account of its anatomy and gave it its scientific name. Monotypic, but specimens from around Ooldea in the southern part of the distribution of this species are, on average, larger in external body and cranial measurements than those from around the type locality in central Australia, and a degree of differentiation between the two regional populations is also indicated by as yet unpublished mitochondrial sequence data. Further work is needed to resolve significance of these contrasts.

Distribution. Sandy deserts of C Australia (S Northern Territory, SE Western Australia, and W South Australia), including portions of the Great Victoria, Tanami, and Great Sandy deserts, and possibly parts of the Simpson Desert; it also occurs in sandy tracts within the desert uplands around Alice Springs, S Northern Territory.

Descriptive notes. Head-body 11-14 cm, tail ¢.2.2-5 cm; weight 50-60 g. The Central Desert Marsupial Mole is a larger and stockier species than the North-western Marsupial Mole ( N. caurinus ). Two large claws on forelimb are consistently broader than on its north-western relative, rhinarial pad is taller and wider, and tail is broaderat its base. Cranium of the Central Desert Marsupial Mole is larger than that of the North-western Marsupial Mole and has a proportionally longer rostrum and smaller auditory bullae. In upper dentition, last molar (M?) is larger and possesses more discrete cusps than corresponding tooth in the North-western Marsupial Mole. In lower dentition, 4-5 small, single-rooted teeth are present in incisor-to-premolar region, rather than three teeth. Notable features of postcranial anatomy of the Central Desert Marsupial Mole include a larger number of ribs (15 rather than 14 in the North-western Marsupial Mole), a larger number of sternal segments (six rather than five sternebrae between manubrium and ziphoid cartilage), and a lesser degree of atrophy of the epipubic that is small but bony rather than cartilaginous. Virtually all of the detailed anatomical knowledge of Notoryctes comes from studies of the Central Desert Marsupial Mole.

Habitat. Sandy substrate, most often in linear dunes or sand plains and probably also parabolic dune complexes and sandy washouts of ephemeral watercourses, with hummock grassland dominated by species of Triodia or Plectrachne (both Poaceae ) and often shrub layer of acacias ( Acacia , Fabaceae ) and casuarinas ( Casuarina, Casuarinacaea ). In linear sand dune country, Central Desert Marsupial Moles appear to favor dune flanks and crests and avoid the hard loamy sediments of the dune swales. On the western margin ofits distribution, in the vicinity of the Warburton Range, the Central Desert Marsupial Mole may occur in regional sympatry or syntopy with the Northwestern Marsupial Mole.

Food and Feeding. Information on the diet of the Central Desert Marsupial Mole comes from attempts to maintain them in captivity and from analysis of gut contents of museum specimens. Captive individuals have accepted numerous food items including eggs, larvae, and pupae of various insect species including ants and termites, earthworms, centipedes, spiders, and gekkonid lizards. Larvae of longicorn beetles ( Cerambycidae ) and scarab beetles ( Scarabaeidae ), moths (Lepidoptera), and commercial mealworms (larvae of Tenebrio molitor , Tenebrionidae ) have been acceptable food items, but adult beetles seem to be rejected. B. Spencer reported his captive Central Desert Marsupial Moles fed readily on ant eggs, larvae, and pupae, but he postulated that adult ants are ingested coincidentally. F. Wood Jones found earthworms ( Lumbricus sp. , Lumbricidae ) to be acceptable to captive Central Desert Marsupial Moles, but others have had the opposite experience. At any rate, earthworms are not usually available in the sandy desert environment occupied by Central Desert Marsupial Moles. There are no observations of feeding above ground by free-living Central Desert Marsupial Moles. Captive individuals will sometimes feed above ground, but they more often grasp large prey items in the mouth and burrow underground to consume them. Small food items like ant or termite eggs are simply licked from the surface, but larger items may be held down or sometimes suspended by forelimbs while they are grasped in the mouth or chewed. Reduction of large food items appears to take place through progressive reduction in the posterior premolar and molar region, and there is no attempt to tear off pieces of food. Gut contents of Central Desert Marsupial Moles have contained a variety of invertebrate prey items and some plant material, most often grass seeds. A specimen examined by C. Brazenor in the mid-1950s contained burrowing sawfly larvae ( Pergidae ), ants of the genus Rhytidoponera ( Ectatomminae ), and legs of leaf beetles ( Chrysomelidae ). K. Winkel and I. Humphrey-Smith examined ten specimens of Central Desert Marsupial Moles and found remains of adult predatory ants (/ridomyrmex spp., Dolichoderinae ), seed-eating ants ( Myrmeciinae ), and their eggs, larvae, and pupae. Grass seeds were also present, but these may have been ingested accidentally from underground caches maintained by Myrmeciinae . More recently, C. Pavey and coworkers examined gut contents of 16 Central Desert Marsupial Moles and compared prey abundances in soil cores taken on sand ridges in the general region of original capture. Five insect orders ( Coleoptera , Hymenoptera, Isoptera, Lepidoptera, and Orthoptera ) were represented in gut samples, along with scorpions, spiders, and plant material. Two main prey types were dominant: social insects (ants and termites) and larvae of beetles. Ants, termites, and beetle larvae also dominated samples obtained in soil cores. Termites alone were potentially underrepresented in gut contents compared with their natural frequency. Results suggest that the Central Desert Marsupial Mole is a dietary generalist despite its specialized adaptations for a subterranean lifestyle.

Breeding. Instances of single and twin pouch young have been recorded for the Central Desert Marsupial Mole. Although only two teats are present in the pouch, the uterus of one pregnant female contained six subterminal fetuses along with two degenerating blastocysts, suggesting a degree of embryonic wastage that is unusual among Australian marsupials. Otherwise, there is no information on timing of mating, duration of pregnancy, and processes of birth and development of the Central Desert Marsupial Mole.

Activity patterns. There has been much speculation regarding timing and environmental correlates of surfacing behavior of the Central Desert Marsupial Mole, but none of the hypotheses are supported by any field data. Surfacing may take place primarily in the evening when soil surface temperatures are dropping but before night air temperatures fall dramatically. Some individuals located on the surface during the day seem to have been moribund while others may have been forced to the surface by high groundwater after flooding. Otherwise, nothing is known about activity patterns of free-living Central Desert Marsupial Moles.

Movements, Home range and Social organization. A Central Desert Marsupial Mole engaged in surface walking or running shows that the forelimb and hindlimb of one side are extended in unison, the claw on the forelimb being used to haul the individual along the surface while the collateral hindlimb is extended to provide additional propulsive force. The result is that the individual proceeds with a rapid sinuous shuffle. Nothing is known about home range size, territoriality, or other social organization or behaviors of the Central Desert Marsupial Mole.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. In a recent assessment, A. Burbidge and coworkers in 2014 recommend a conservation status of Least Concern for the Central Desert Marsupial Mole. There are recent records from several localities in central Australia and one from the Great Victoria Desert. Burrows of Central Desert Marsupial Moles have been found in many more localities, but it is unclear how populated somesites are and how long these burrows may persist within the soil profile.

Bibliography. Bennison et al. (2014), Benshemesh (2004, 2008, 2014), Benshemesh & Johnson (2003), Beveridge & Durette-Desset (1985), Burbidge & Aplin (1996), Burbidge et al. (1988), Corbett (1975), Dennis (2004), Dickman, Burbidge et al. (2008), Finlayson (1961a), Howe (1975), Johnson (1995), Johnson & Walton (1989), Maxwell et al. (1996), Paltridge (1998, 2002), Pavey et al. (2012), Pearson & Turner (2000), Stirling (1888b, 1889), Winkel & Humphrey-Smith (1988), Woinarski et al. (2014be), Wood Jones (1924).

Figures

Plate 13 Species Accounts

Distribution. Sandy deserts of C Australia (S Northern Territory, SE Western Australia, and W South Australia), including portions of the Great Victoria, Tanami, and Great Sandy deserts, and possibly parts of the Simpson Desert; it also occurs in sandy tracts within the desert uplands around Alice Springs, S Northern Territory.