Bettongia penicillata, Gray, 1837

Russell A. Mittermeier & Don E. Wilson, 2015, Potoroidae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 600-628 : 626-627

4.

Brush-tailed Bettong

Bettongia penicillata

French: Bettong a queue en brosse / German: Biirstenrattenkanguru / Spanish: Betong de cola de cepillo

Other common names: Brush-tailed Rat-kangaroo, Woylie

Taxonomy. Bettongia penicillata Gray, 1837 ,

type locality not given. Identified by T. Iredale and E. Le. G. Troughton in 1934 as New South Wales, Australia.

The nominate subspecies penicillata (Gray, 1837 ) of south-eastern Australia is extinct; the relationship of this eastern population with B. tropica requires clarification. Although eastern (nominate penicillata ) and western subspecies (ogilbyi) have traditionally been recognized, their distinction and the taxonomic affinity of central Australian populations remain unclear. One extant subspecies recognized.

Subspecies and Distribution.

B. p. ogilbyi Waterhouse, 1841 — far SW Western Australia (Dryandra Woodland, Kingston, Perup Nature Reserve, and Tutanning Nature Reserve). Introduced or reintroduced into many sites in Western Australia, South Australia, and New South Wales.

Descriptive notes. Head—body 28.9-36 cm, tail 25-36 cm; weight 0.8-1.8 kg. Grizzled grayish brown dorsally, paler ventrally. Faint hip stripe; brownish on face, limbs, and tail. Tail paler ventrally and darkens distally, with prominent dark dorsal crest toward tip. Diploid chromosome numberis 22.

Habitat. Dry sclerophyll forest and woodland with dense understory. Historically occurred also in a wider range of arid and semi-arid habitats, including spinifex grasslands, mallee woodland, and shrubland. Prefers well-drained sandy soils. From sea level to ¢.300 m elevation.

Food and Feeding. Mycophagous, feeding primarily on hypogeal (truffle-like) fungi obtained by digging with the strongly clawed forepaws. Roots, tubers, seeds, plant exudate, and invertebrates are also eaten. Some seasonal and geographical variation in diet occurs, reflecting differing availability of fungi. Known to cache seeds. Does not require access to free water.

Breeding. Females reach sexual maturity at ten months, males at twelve months. Females breed continuously, producing a single young per pregnancy and up to three young per year. They exhibit embryonic diapause and usually mate within a few hours of having given birth. The estrous cycle is 22-23 days and gestation is 21 days. Following birth, the young spends c¢.3-5 months in the pouch and is weaned at c.4-5 months. After sharing its mother’s nest for some months after weaning, the young disperses.

Activity patterns. Nocturnal; spends daylight hours alone in a nest, emerging after dark, or sometimes at dusk, to forage, and returning before dawn. Nests are elaborate and well concealed, constructed over a shallow depression dug under dense vegetation or at the base of shrubs or grass tussocks. Nests are ovoid in shape, with a single entrance, an outer layer of grass and bark, and an inner layer of finely shredded plant material. Brush-tailed Bettongs have multiple nests in their home ranges and can have three or four nests in use at any one time; nest use appears random, with an individual nest rarely used for more than three days at a time.

Movements, Home range and Social organization. Primarily solitary; both males and females are generally aggressive toward members of the same sex. Home range estimates are 28-43 ha for males and 15-28 ha for females, but the size varies with habitat quality and population density. Within the home range a smaller core nesting area of 2—4 ha is defended. These core nesting areas are non-overlapping for males, but those of males and females may overlap to some extent. In the larger foraging areas there is considerable overlap, both within and between sexes. Males are more transient than females, with individuals recorded as moving up to 9 km. Female philopatry and malebiased dispersal can be inferred from genetic data.

Status and Conservation. CITES Appendix I. Classified as Critically Endangered on The IUCN Red List. The eastern population is listed as extinct and the western population is listed as endangered in Australia. Although originally widespread and common across southern and central Australia, the Brush-tailed Bettong started to decline in eastern Australia in the middle to late 1800s, and by 1970s persisted only at four localities in far south-western Australia. This catastrophic decline appears to have resulted from predation by introduced Red Fox (Vulpes vulpes) and feral cats (Felis catus), as well as changes to habitat brought about by the introduction of domestic livestock, European Rabbits (Oryctolagus cuniculus), changes in fires regimes, and clearing of habitat for agriculture. In some areas, the species was also persecuted directly as a crop and/or garden pest. In 1980s, the implementation of broad-scale fox controlled to the spectacular recovery of Brush-tailed Bettong populations in south-west Western Australia, and the species naturally recolonized, or was reintroduced to, several additional locations. As a consequence, the Brush-tailed Bettong was removed from the Western Australia and National threatened-species lists in 1996. It was also reintroduced (or introduced) to many additional sites in Western Australia, as well as several sites in South Australia and New South Wales. The results of these reintroductions have been mixed, the most successful having been at sites free from introduced predators (foxes, cats), including islands and fenced enclosures. Since 2001, many populations of this potoroid have declined again, in some cases to extinction. The species has now been relisted as threatened. The cause of these more recent declines remains unclear, although increased feral-cat predation (cats may have benefited from successful fox control) and disease have been implicated. Several Recovery Plans have been prepared and captive-breeding populations established at several locations.

Bibliography. Botero et al. (2013), Burbidge et al. (1988), Christensen (1977), Christensen & Leftwich (1980), Claridge et al. (2007), Finlayson, G.R., Finlayson & Dickman (2010), Finlayson, H.H. (1958b), Gray (1837), Groom (2010), Hayman (1989), Iredale & Troughton (1934), Kinnear, Sumner & Onus (2002), Menkhorst & Knight (2001), Murphy et al. (2005), Pacioni et al. (2011, 2013), Priddel & Wheeler (2004), Sampson (1971), Seebeck et al. (1989), Short (1998), de Tores & Start (2008), Troughton (1967), Wayne, Friend et al. (2008), Wayne, Maxwell, Ward, Vellios, Ward et al. (2013), Wayne, Maxwell, Ward, Vellios, Wilson et al. (2015), Woinarski, et al. (2014bl, 2014bm), Wood Jones (1924), Yeatman & Groom (2012).

Figures

1. Rufous Bettong (Aepyprymnus rufescens), 2. Burrowing Bettong (Bettongia lesueur), 3. Eastern Bettong (Bettongia gaimardi), 4. Brush-tailed Bettong (Bettongia penicillata), 5. Northern Bettong (Bettongia tropica), 6. Long-footed Potoroo (Potorous longipes), 7. Long-nosed Potoroo (Potorous tridactylus), 8. Gilbert's Potoroo (Potorous gilbertii)

Subspecies and Distribution. B. p. ogilbyi Waterhouse, 1841 — far SW Western Australia (Dryandra Woodland, Kingston, Perup Nature Reserve, and Tutanning Nature Reserve). Introduced or reintroduced into many sites in Western Australia, South Australia, and New South Wales.