Golden Bandicoot

## Description

The golden bandicoot (Isoodon auratus ) is a short-nosed bandicoot found in northern Australia. It is the smallest of its genus.

The golden bandicoot is now a threatened species. It was once found throughout much of northwestern Australia, with even a patch on the New South Wales/South Australia border, but it is now restricted to the Kimberley region of Western Australia, and to Augustus, Barrow and Middle Islands off of Western Australia (I. auratus barrowensis ) and Marchinbar Island of Northern Territory. It is distinguished from the brown bandicoots by its golden colouring and much smaller size.

It averages about 35 cm (or 14 in.) in length from head to tail and weighs between 260-655g (or 9–23 oz) with an average of 310 g (11 oz). It is the smallest of the short-nosed bandicoots with a golden colour back, hence the name, finely streaked with black fur. The sides and face are a faded light rust colour, and the underbelly is pale amber. The feet are the same colour as the underbelly and have sharp claws. The species was first described in 1897 from a specimen collected near Derby, Western Australia. As with most bandicoots, the golden bandicoot has a rather long, flat, pointy nose. It is an omnivore, consuming succulents, insects, plant bulbs, and small reptiles. The golden bandicoot is nocturnal, foraging at night by digging small holes in the ground to find food.

The largest golden bandicoot population lives on Barrow Island because no cats or foxes have been introduced to the island, and other populations exist on Middle, Marchinbar, Augustus Islands. Small populations on mainland Australia are located in the Northern Territory and Western Australia. The golden bandicoot once lived all throughout Central Australia, but by 1992 it had been reduced to a small area in northwest Kimberly and Arnhem Land. In 2000, it was assumed that the species was extinct on the mainland. Birds are the main threat to the species, and bandicoots must compete with rabbits for resources.

## Appearance

This small marsupial is endemic to Australia. The fur of the animal is golden-brown. By its appearance, the Golden bandicoot reminds a hunched rat with a long tail. As opposed to other marsupials, webbed toes on their hind feet create a comb, which is used in grooming. While most bandicoot species exhibit considerably large ears and elongated snouts, the Golden bandicoots have short muzzles due to belonging to the genus of short-nosed bandicoots (Isoodon).

## Distribution

These marsupials are found only in Australia, where their range is limited to scattered areas in Western Australia and the Northern Territory. They are also known to inhabit Barrow, Middle, Augustus, Marchinbar and Uwins Islands. The preferred environment of the Golden bandicoot is dry savannah, dominated by acacia or eucalyptus. They frequently occur in vine thickets and coastal areas with scrub growth. The Golden bandicoots also favor rainforest margins, sandstones as well as rocky and spinifex areas.

## Behavior

These marsupials are generally solitary. They only socialize when mating or rearing their offspring. They are highly territorial with each individual having its own distinct home range. These nocturnal animals forage during the nighttime hours, resting in their burrows or nests by day. Burrows of these bandicoots are usually dug into the sand (though some individuals are known to reside in caves), while their nests are made out of flattened plant material. Golden bandicoots are able to see quite well in low visibility. As nocturnal animals, these bandicoots have a well-developed sense of hearing. They also use their keen sense of smell when foraging, while their whiskers help them perceive their environment.

## Diet

These omnivorous animals primarily feed upon termites, ants and various other insects, complementing their diet with small reptiles as well as turtle eggs. Golden bandicoots are also known to eat seeds, roots, tubers and other plant material.

## Reproduction

Little is known about the mating system of Golden bandicoots, but it is known that males disperse soon after copulation, suggesting that they may exhibit either polygynous or polygynandrous (promiscuous) mating system. These productive breeders mate all year round with two peak periods: one occurs in August, during the dry season, while the other takes place at the wet season, between December and January. Gestation period in this species is one of the shortest among mammals - 12.5 days. Females give birth to 2 - 3 juveniles, which immediately climb into her pouch, remaining there for approximately eight weeks. As soon as juveniles are weaned, the female is ready to mate again. Sexual maturity is reached at 3 months old.

## Population

### Population threats

Golden bandicoots have long suffered from changes in fire regimes. They have been hunted by exotic predators such as feral cats, and have competed with rabbits. As a result, Golden bandicoots have lost most of their original range.

### Population number

According to the IUCN Red List, total population size of the Golden bandicoot is unknown for today. However, specific populations have been estimated in following areas: on Barrow Island - at least 20,000 individuals; on Middle Island – 1, 000 individuals; on Marchinbar Island - 1,400 animals. Population numbers of Golden bandicoots are decreasing today, and the animals are currently classified as Vulnerable (VU) on the IUCN Red List.

### Ecological niche

On one hand, Golden bandicoots control populations of insect species they consume (e.g. cockroaches, termites or ants), thus benefiting humans, who consider these insects as pests. On the other hand, due to feeding upon vegetation, they serve as seed dispersers, helping some plants survive. In addition, bandicoots are key prey species for exotic and native predators of their range.

## Fun Facts for Kids

The word "bandicoot" originates from Telugu word "pandikokku", meaning "pig-rat". Meanwhile, "pig-rats" were rodents, endemic to India and Sri-Lanka, belonging to bandicoot genus.

The strong and powerful hind legs help these animals when jumping. The second and third toes on their feet are webbed, as common in kangaroos.

When spotting prey item underground, a bandicoot will start digging a hole with its front paws, trying to get to its prey with its long snout.

These highly vocal animals use a variety of calls in their daily life. Thus, they are known to snuff when foraging. And finally, when they find food, the bandicoots usually give out a grunting sound, similar to that of a piglet. In addition, they tend to emit high-pitched calls when disturbed.

As a result of adaptation to the specific lifestyle, the pouch of bandicoots faces backward rather than forward as in other marsupials. Due to opening backward, the pouch remains clean as the animal digs the ground when foraging.