Bettongia lesueur (Quoy & Gaimard, 1824)

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 : 625-626

2.

Burrowing Bettong

Bettongia lesueur

French: Bettong de Lesueur / German: Lesueur-BUrstenrattenkanguru / Spanish: Betong de Lesueur

Other common names: Boodie, Burrowing Rat-kangaroo, Lesueur’s Rat-kangaroo

Taxonomy. Hypsiprymnus lesueur Quoy & Gaimard, 1824 ,

“I'tle Dirck-Hatichs” (= Dirk Hartog’s Island, Shark Bay, Western Australia).

Morphological variation across the range has resulted in several island and mainland subspecies (some undescribed) being proposed. Further study required to clarify the significance of these differences. Monotypic.

Distribution. Dorre I and Bernier I (in Shark Bay) and Barrow I (off the Pilbara coast), Western Australia. Reintroduced to Faure I in Shark Bay and Boodie I, off S Barrow I (both Western Australia), as well as into fenced reserves on the mainland (Heirisson Prong in Western Australia, Scotia Sanctuary in New South Wales, and Arid Recovery Reserve, Roxby Downs in South Australia).

Descriptive notes. Head-body 28-36 cm,tail 20.7-28.5 cm; weight 0-68.1 kg. A pale, stocky potoroid with short muzzle, short rounded ears, and short thick tail. Yellowish brown to gray dorsally, paler ventrally. Tail and head sometimes brownish. Pale hip stripe, bare pink skin around eyes. Ears pink inside, exterior finely furred and darker toward tip. Tail lightly furred, dark dorsally toward tip; a pale tail tip is sometimes present. Males generally larger than females. Barrow Island animals significantly smaller than those on Bernier and Dorre Islands. Diploid chromosome numberis 22.

Habitat. Arid and semi-arid grassland, woodland, and shrubland, from sea level to c.300 m. Prefers firm loamy soils for burrowing.

Food and Feeding. Omnivorous, consuming roots, tubers, bulbs, seeds, leaves, stems, fungi, and invertebrates. Will also eat carrion. Diet varies with season. Known to cache seeds. Does not require access to free water.

Breeding. Females reach sexual maturity from seven months of age, males at 14 months. Females are potentially continuous breeders, although reproduction typically is reduced over the summer. One young is produced per pregnancy and up to two young can be raised per year. Females exhibit embryonic diapause and mate within a day of having given birth. The estrous cycle is 23 days and gestation is 21 days. Following birth, the young spends about four months in the pouch and is weaned at ¢.5-5 months. The mating system is thought to be a harem-defense system, males defending access to females rather than territory, but additional behavioral and genetic data are required.

Activity patterns. Nocturnal; emerges from burrow after sunset and returns before dawn. The only potoroid that regularly constructs and uses burrows in which to shelter during the day. The complexity of these burrow systems (warrens) appears related to soil type and topography; both simple and complex burrow systems have been observed, the number of entrances varying from two to more than 100. Rudimentary nests of vegetation are constructed within the warren. Bettongs move along well-established pathways from warrens to feeding areas. May forage up to 2-2 km away, although most activity occurs within 500 m of the warren.

Movements, Home range and Social organization. This species is more gregarious than other potoroids, butits social system is not fully understood. In captivity, males are aggressive and intolerant of each other, although females are more social. In contrast, wild populations show large numbers of males coexisting, with overlapping foraging ranges. Unusually for a potoroid, multiple individuals routinely share a single warren during the day. Simple social groups comprise one male and several (sometimes related) females that occupy a warren and over time utilize multiple warrens within their home ranges, males changing warrens more frequently than do females; males appear not to share warrens with other males. More complex social groups of 20-70 individuals occupying interconnected warrens have also been observed, but the social composition and organization of these large groups is presently unknown. There is some evidence of dominance hierarchies forming among individuals. Although gregarious during the day, Burrowing Bettongs are largely solitary when foraging at night. Home ranges in a reintroduced population were estimated to be 26-34 ha. Dispersal appears male-biased. In a reintroduced population it occurred around the time of sexual maturity, males dispersing a greater distance (mean 4-6 km) than females (mean 1-1 km).

Status and Conservation. CITES Appendix I. Classified as Near Threatened on The IUCN Red List. The Australian mainland population is listed as extinct and island populations as vulnerable in Australia. Formerly widespread and common throughout central, southern, and south-western Australia, this species is now extinct on the mainland and on Dirk Hartog Island. The decline of the Burrowing Bettong commenced in south-eastern Australia in mid-1800s and spread westward, with the last known mainland specimens collected in south-western Australia in 1940s, although Aboriginal people report that the species persisted in central Australia until ¢.1960.

This catastrophic decline appears to have resulted from predation by introduced Red Fox (Vulpes vulpes) and domestic/feral cats (Felis catus), as well as changes to habitat caused by introduced domestic livestock, European Rabbits (Oryctolagus cuniculus), changesin fires regimes, and clearing of woodland for agriculture. In some areas Burrowing Bettongs were also directly persecuted as crop and/or garden pests. Fortunately, populations of this potoroid persisted on four islands: Bernier, Dorre, Barrow, and Boodie. In 1984 the Boodie Island population accidently became extinct during a Roof Rat (Rattus rattus) extermination campaign, but it was reestablished in 1993 through the translocation of animals from nearby Barrow Island. The surviving island populations have also been used to source reintroductions to other sites. While several of these reintroductions were unsuccessful, owing primarily to predation by feral cats, other releases to islands free of introduced predators or with fenced enclosures have been more successful. Populations of Burrowing Bettongs now appear well established and increasing at Faure Island and Heirisson Prong, at Arid Recovery Reserve, Roxby Downs, and at Scotia Sanctuary. The endemic island populations ofthis species vary in size from 650 to 3400 individuals, but they are known to fluctuate widely in response to drought and so remain vulnerable to stochastic extinction. These populations are also highly vulnerable to the introduction of predators, competitors, or disease, and access to the islandsis therefore restricted. A Recovery Plan has been prepared and captivebreeding populations have been established at several locations.

Bibliography. Burbidge & Short (2008), Burbidge et al. (1988), Christensen & Burrows (1995), Claridge etal. (2007), Finlayson, G.R. & Moseby (2004), Finlayson, G.R., Finlayson & Dickman (2010), Finlayson, H.H. (1958b), Hayman (1989), Menkhorst & Knight (2001), Parsons et al. (2002), Richards (2012b), Richards, Morris & Bur bidge (2008), Ride & Tyndale-Biscoe (1962), Robley et al. (2001), Sander et al. (1997), Seebeck et al. (1989), Short (1998), Short & Turner (1993, 1999, 2000), Short et al. (1997), Stodart (1966b), Troughton (1967), Tyndale-Biscoe (1968), Woinarski et al. (2014bh, 2014bi, 2014bj, 2014bk), Wood Jones (1924).

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)

Distribution. Dorre I and Bernier I (in Shark Bay) and Barrow I (off the Pilbara coast), Western Australia. Reintroduced to Faure I in Shark Bay and Boodie I, off S Barrow I (both Western Australia), as well as into fenced reserves on the mainland (Heirisson Prong in Western Australia, Scotia Sanctuary in New South Wales, and Arid Recovery Reserve, Roxby Downs in South Australia).