Greater Bilby

## Description

The greater bilby (Macrotis lagotis ), often referred to simply as the bilby since the lesser bilby (Macrotis leucura ) became extinct in the 1950s, is an Australian species of nocturnal omnivorous animal in the order Peramelemorphia. Other vernacular names include dalgyte, pinkie, or rabbit-eared bandicoot. Greater bilbies live in arid parts of northwestern and central Australia. Their range and population is in decline.

## Appearance

The Greater bilby, or otherwise known as Australia's Easter Bunny, is a ground dwelling (bandicoot) marsupial. The kangaroo-like large, hairless ears and long, slender hind legs give the animal a rather funny appearance. The fur of the marsupial is soft and silky, colored with blue-grey and exhibiting thin, tan colored patches. The belly of the animal is white, whereas the long and hairless snout is pink. The long tail of the bilby is grey at the base, then turning to black and ending with white, naked tip, which has a tuft of long hairs. When galloping, the animal drags its tail behind itself like a stiff banner.

## Distribution

Once widely distributed and abundant across southern Australia, these animals are currently restricted to small, scattered area, where they are presented by two subspecies. These are: the Western bilbies, occurring between Western Australia and the Northern Territory; and the Eastern bilbies, endemic to southwest Queensland. These marsupials usually inhabit dry and hot areas such as deserts, dunes or grasslands. They are known to favor tussock and hummock grasslands as well as acacia shrublands.

## Behavior

These marsupials are solitary animals, though some individuals may display social behavior. Thus, females of this species have been known living in pairs. Although they may have overlapping home ranges, they usually ignore conspecifics except for mating. As semi-fossorial animals, they dig a bit spiraling burrows, which are normally 2 meters in depth and 3 meters long. Each burrow has several exits so as the animal can escape if attacked by a predator. Meanwhile, each individual may have multiple burrows throughout its territory. Greater biblies are nocturnal animals. They come out of their burrows at dusk in order to find food or mate, returning to their burrows periodically during the night, typically to rest or hide from predators.

## Diet

These omnivorous animals mainly feed upon seeds, grasses, bulbs, larvae, termites, ants, spiders, fruit, fungi and lizards, complementing their diet with eggs, snails and small mammals.

## Reproduction

Greater bilbies have polygynous mating system, which relies on social hierarchy: the dominant male and the dominant female mate together, whereas lower-ranked males mate with females whose status is equal or lower than theirs. Breeding occurs all year round. During a year with suitable environmental conditions, a bibly female can yield up to 4 litters, each one containing 1 - 2 (sometimes up to 4) babies. After 14 days of gestation, the newborn babies climb into the pouch of their mother, remaining there for about 75 days. As they come out of the pouch, the mother still cares for them for 14 days, after which they leave the burrow, becoming completely independent. Males of this species are sexually mature at 8 months old, when they weigh 800 g. Females are mature by 5 months of age, weighing about 560 g.

## Population

### Population threats

These animals currently face loss of their natural habitat. Greater bilbies are hunted by introduced predators like cats and foxes. They compete for food and share the same diet with introduced animals such as cattle, sheep and other domestic livestock. In addition, bilbies compete with rabbits for food and burrows.

### Population number

According to the IUCN Red List, total population size of the Greater bilby is under 10,000 individuals. Specific populations of this species have been estimated in following areas: about 500 individuals on Thistle Island; 500 individuals in Arid Recovery; 100 individuals in Venus Bay; 200 individuals in Peron; 40 individuals in Scotia; 200-500 individuals in Queensland; less than 1,000 individuals in the Northern Territory and 5,000-10,000 individuals in non-reintroduced Western Australia. Overall, numbers of Greater bilbies’ population are decreasing today, and the animals are classified as Vulnerable (VU) on the IUCN Red List.

### Ecological niche

Greater bilbies have an important role as prey for their natural predator (red foxes, cats, dingoes). Also they serve as 'ecosystem engineers' by digging pits filled with seeds of water which becomes 'fertile patches' in the Australian desert.

## Fun Facts for Kids

According to information, acquired at the Australian National University, Greater bilbies got their name from the Yuwaalaraay aboriginal language.

The tongue of these animals is long and narrow. Their upper jaw holds 26 teeth, while the lower jaw has 22 teeth.

Pouches of Greater bilbies open backward like these of koalas or wombats. Due to facing backward, their pouches remain clean when the animals dig the ground.

Although Greater bilbies have kangaroo-like hind legs, they do not hop. Instead, when moving fast, they tend to gallop like a horse.

They give out sounds, which can be characterized as a cross between grunting and squeaking.

Easter baskets of Australian children traditionally have chocolate bilbies rather than Easter bunnies.

These animals have no water requirements, getting all moisture they need from their food.

The large and hairless ears of Greater bilby provide the animal with keen sense of hearing, thus helping escape predators. They also allow the bibly to cool off during hot days.

On each of its hind feet, the animal has two small toes, growing together behind the large middle toe and forming so-called "double nail", which is used in grooming.

Within just three minutes, this accomplished and fast digger will dig a deep hole where it will disappear. Greater bibly usually digs steep and deep burrows to protect itself from predators.