Perameles gunn, Gray, 1838

Russell A. Mittermeier & Don E. Wilson, 2015, Peramelidae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 362-398 : 391-392

5.

Eastern Barred Bandicoot

Perameles gunn

French: Bandicoot de Gunn / German: Tasmanien-Langnasenbeutler / Spanish: Bandicut listado oriental

Other common names: Gunn's Bandicoot, Tasmanian Barred Bandicoot

Taxonomy. Perameles gunnii Gray, 1838 ,

“ Van Diemen’s Land [= Tasmania ],” Australia.

There is considerable debate over whether mainland and Tasmanian populations of this species should each be accorded subspecific status. Early work reported minor morphological differences between the two forms, but some authors have considered these too small to warrant subspecific distinction. Genetic differences and additional separation based on analysis of nDNA and mtDNA, however, suggest that subspecific recognition is warranted. Since original description was based on Tasmanian specimens, the mainland Australian population requires formal description and naming. Currently treated as monotypic.

Distribution. N & E Tasmania including Bruny I; persists also (very small numbers) in extreme SE Australia (S Victoria).

Descriptive notes. Head-body 27-35 cm,tail 7-11 cm; weight 0.5-1.1 kg (Victoria), 0.5-1.4 kg (Tasmania). Adult males weigh at least 10% more than adult females. Dorsal fur is a grizzled fawnish brown to gray above, with 3-4 conspicuous and highly distinctive pale bars running from mid-flank region to rump. Ventral fur is light slate-gray, feet and upper surface oftail white, and ears are long and held erect.

Habitat. Prefers open grassland habitats that also provide some access to denser cover for shelter. In Victoria, it inhabited perennial tussock grassland mixed with areas of savanna woodland and, until recently, could be found in semi-natural situations such as golf courses, gardens, parks, and farmland near urban settlement. In Tasmania, this bandicoot occurs in native and exotic grasslands, woodland, and open forest with a grassy understory, and also in farmland and cultivated cropland. Nest is lined and constructed from grass and other debris in depression on ground surface or under cover of shrubs.

Food and Feeding. Some food is taken from the ground surface, including seeds, fallen fruits, insects, and small vertebrates, and some is excavated. Animals use their strong and stoutly clawed forefeet to dig conical holes to depths of 15-20 cm, uncovering earthworms, larvae, bulbs, tubers, roots, and subterranean fungi. Diet changes seasonally, reflecting shifts in the availability of different foods throughoutthe year.

Breeding. Reproductive activity usually begins in winter and continues to early summer, presumably when food resources are most readily available, but in Victoria some females have been recorded breeding year-round. Females carry litters of 1-5 young (2-3 more usual), with larger litters usually produced in spring rather than at other times. Eight nipples are present, young in successive litters within a season attaching to nipples that have regressed in size from previous use. Gestation is just 12-5 days; young leave the pouch at 48-53 days, and are weaned at c.60 days. Females may mate while lactating and give birth to a furtherlitter just after weaning the preceding one, thus allowing 2-3 litters to be produced within a season. Sexual maturity is achieved by females at ¢.3 months and by males at 4-5 months, and some animals may breed in the season oftheir birth. Despite the high reproductive rate and production of 10-12 young peryear, usually few young (10-15%) are recruited into adult population owing to high rates of mortality after pouch-exit and weaning.

Activity patterns. This bandicootis strictly nocturnal. Individuals emerge at dusk or after dark and exhibit several peaks of activity during the night. Most time is spent in foraging, but males probably spend relatively more time than females in patrolling their home ranges. Animals return to their nests before dawn.

Movements, Home range and Social organization. Like most other peramelids, this species is solitary except for brief periods of courtship and mating and when females have dependent young. Home ranges of males are usually large, averaging 13-20 ha in Victoria and ¢.26 ha in Tasmania, and encompass those of several females. In contrast, female ranges average 2-5-4 ha. There is some overlap in the ranges occupied by each sex, but core areas are usually discrete and separate. It is not clear how individuals maintain the integrity of their range boundaries, but direct aggression may play a role. Population densities of ¢.2 ind/ha have been reported in Victoria and 0-3-2-4 ind/ha in Tasmania, although densities in Tasmania may rise to 8:5 ind/ha in optimal habitat.

Status and Conservation. Classified as Near Threatened on The IUCN Red List. Exhibits a decreasing population trend. Historically, this species occurred from southeastern South Australia east to Melbourne area of Victoria, but in this region it now persists, in very small numbers, only in southern Victoria. It is known also from subfossil material from Flinders and Hunter islands, in Bass Strait, but no longer occurs there. In Tasmania, it has declined to low numbers in the Midlands region in recent decades, and its distributional strongholds now are in south-eastern and north-western Tasmania. It occurs also on Bruny Island and has been introduced to Maria Island. Declines in the Midlands were driven by loss of habitat and the intensification of agricultural and pastoral activity, and probably also by increased predation pressure that arose from predators switching their focus from the European Rabbit (Oryctolagus cuniculus) to the Eastern Barred Bandicoot after rabbit-control began, in 1950s. There is also concern that, as populations of the native Tasmanian Devil (Sarcophilus harrisii) continue to crash following the spread of a contagious facial tumor disease, numbers of feral cats (Felis catus) are increasing and placing bandicoots and other native animals under great stress. Introduction of the Red Fox (Vulpes vulpes) to Tasmania, in what was probably a deliberate act of “bioterrorism” in late 1990s, will, if this carnivore becomes established, act further to drive populations of present species to very low levels. In Victoria, this peramelid occupied a shrinking range for much of 20" century before the last known wild population was extirpated, in 2002. Many factors have been attributed to the decline, including loss of habitat for agriculture or development, habitat degradation due to livestock and introduced feral herbivores such as the European Rabbit, deliberate persecution from landholders, inadvertent poisoning through pesticides and herbicides, diseases such as toxoplasmosis, and predation by introduced carnivores. Predation appears to have been the prime cause of its final expiration in the wild in mainland Australia. Fortunately, however, before it was lost altogether, a few individuals were removed from the wild for breeding in captivity, and these have provided the founders for subsequent reintroduction attempts. The Victorian form now persists in three sites where it is protected from predation: Mount Rothwell Biodiversity Interpretation Centre, Hamilton Community Parklands, and Woodlands Historic Park. It has been reintroduced to a furtherfive sites but, after initial breeding successes, combinations of drought and predation from feral cat and, especially, Red Fox drove these populations to extinction. In 2012, the bandicoot was introduced to French Island, the largest island in Victoria (170 km?), in a pilot trial. Males were sterilized and animals retrapped at the conclusion of the trial; a decision about a broader-scale release is yet to be made. French Island has suitable habitat for this peramelid and has the major advantage that it is fox-free. Recovery efforts in Victoria have been intensive for more than 25 years, and involve many dedicated individuals and organizations. As a result, the mainland form is likely to be kept in existence for the foreseeable future, albeit in wildlife parks, zoological gardens, and predator-free compounds. Until the scourge of the cat and the Red Fox can be overcome, large wild populations are very unlikely to be seen again. The Near Threatened classification for this species on The [UCN Red List was made in 2008. It is unlikely to receive such a sanguine assessment when it is reviewed again in future.

Bibliography. Bryant & Jackson (1999), Dickman (2012), Driessen et al. (1996), Dufty (1994a, 1994b, 1994c, 1995), Freedman (1967), Freedman & Joffe (1967), Green (2007), Heinsohn (1966), Hill et al. (2010), Hocking (1990), Kemper (1990), Lyne (1951), Mallick, Driessen & Hocking (1997 2000), Mallick, Haseler et al. (1997), Mallick, Hocking & Driessen (1997, 1998), Menkhorst & Seebeck (1990), Obendorf & Munday (1990), Opie et al. (1990), Reimer & Hindell (1996), Robinson et al. (1993), Seebeck (1979, 2001), Sherwin & Brown (1990), Tyndale-Biscoe & Renfree (1987), Watson & Halley (2000), Westerman & Krajewski (2000), Westerman etal. (2012), Winnard & Coulson (2008), Woinarski et al. (2014k, 20141, 2014m).

Figures

On following pages: 3. Northern Brown Bandicoot (/soodon macrourus); 4. Western Barred Bandicoot (Perameles bougainville); 5. Eastern Barred Bandicoot (Perameles gunnii); 6. Long-nosed Bandicoot (Perameles nasuta), 7. Giant Bandicoot (Peroryctes broadbenti); 8. Raffray’s Bandicoot (Peroryctes raffrayana)

Distribution. N & E Tasmania including Bruny I; persists also (very small numbers) in extreme SE Australia (S Victoria).