There are no known adverse effects of Macrotis lagotis on humans.
While native species such as carpet pythons (Morelia spilota), monitor lizards (Varanidae), and some raptors (Accipitridae) are potential predators of greater bilbies, the most common and destructive predators are introduced species. Non-native species that prey on greater bilbies include dingos (thought to have been introduced in Australia about 3500 years ago), red foxes, and feral cats. Red foxes were brought to Australia for the purpose of recreational hunting in 1855 by European settlers. Within 100 years of their introduction, red foxes spread across continental Australia and currently inhabits all regions of the continent with the exception of the tropical northern region of Australia. Domestic cats were originally released throughout Australia around 1855 to control the population of another invasive species, European rabbits, as well as mice and rat populations. Domestic cats quickly expanded over the entire continent of Australia, killing many native species.
Known Predators:
Greater bilbies are known for their large, relatively hairless, rabbit-like ears, and long pointed snouts with sensory vibrissae and a hairless pink nose. Their fur is soft, silky and bluish grey in color with a mix of fawn over the majority of the body. The belly is covered in white or cream fur. The first part of the tail is the same bluish grey as the body with the remainder of it being black and the final 40% being pure white. The pouch of females opens to the rear so as to avoid filling with soil when the animal is burrowing. The forelimbs are strong and consist of three clawed digits and two clawless digits. Greater bilby hind limbs are slender and similar to those of kangaroos. Rather than hopping, bilbies use their legs to gallop around the desert. Their tongues are long, sticky, and slender, making it easy to catch termites. Males and females are sexual dimorphic, with the male's body mass being twice that of females (800 to 2500 g for males relative to 600 to 1100 g for females). Along with being larger, males also have enlarged foreheads and longer canines (National Recovery Plan for the Greater Bilby).
Range mass: 600 to 2500 g.
Range length: 29 to 55 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Average basal metabolic rate: 2.4 W.
The oldest greater bilby in captivity lived about 10 years, although 6 to 7 years of age is a typical maximum lifespan in captivity. The lifespan of greater bilbies in the wild is unknown.
Range lifespan
Status: captivity: 10 (high) years.
Average lifespan
Status: captivity: 6-7 years.
Average lifespan
Status: captivity: 7.2 years.
Average lifespan
Status: captivity: 5.0 years.
Greater bilbies are commonly found in dry, hot areas including deserts, dunes, and grasslands. There are three main vegetation types commonly associated with bilby habitat. These are tussock grassland commonly found on the hills and uplands, mulga woodlands and shrublands, and hummlock grasslands found on dunes and sandy plains. Greater bilbies are fossorial, found in areas of rocky and clayey soil.
Habitat Regions: terrestrial
Terrestrial Biomes: desert or dune ; savanna or grassland
Greater bilbies were historically found over 70% of continental Australia with populations throughout South Australia, Western Australia, the Northern Territory, and New South Wales. Limited populations were also found in southwestern Queensland. Upon the introduction of feral cats (Felis silvestris), red foxes (Vulpes vulpes), and rabbits Oryctolagus cuniculus by Europeans, the home range of Macrotis lagotis was greatly reduced. Today, bilbies are limited to 20 to 30% of their original territory. Macrotis lagotis is found in Great Sandy, Tanami, and Gibson deserts in northwest Australia and the south west tip of Queensland. Greater bilbies are now considered extinct in South Australia. Reintroduction programs have begun in southern South Australia, southwestern Queensland, western New South Wales, and areas of Western Australia with some success due to the addition of predator-proof enclosures and intense monitoring of reintroduced populations.
Biogeographic Regions: australian (Native )
Greater bilbies do not drink water, they obtain water from their food. They have an opportunistic diet consisting of seeds, especially those of the grasses Dactyloctenium radulans and Yakirra australiense, bulbs, larvae, termites, ants, spiders, fruit, fungi, lizards and occasionally eggs, snails, or small mammals. The proportion of insect to plant material that makes up their diet depends on the habitat and the season. Along with a keen sense of smell, greater bilbies have excellent hearing. Placing their enormous ears against the ground, greater bilbies are able to hear termites and other insects burrowing underground. They then use their sharp claws and strong forelimbs to dig up insects, bulbs, and other buried food. Since greater bilbies have soft fur that does not protect their bodies well from termite bites, they dig tunnels leading to termite chambers and lap them up with their long, slender tongues. Unfortunately, this method of feeding leads to a large consumption of soil and sand as well. Controlled fires are actually important to greater bilbies because fire promotes growth and seed production of preferred food plants.
Animal Foods: mammals; reptiles; eggs; insects; terrestrial non-insect arthropods; mollusks
Plant Foods: roots and tubers; seeds, grains, and nuts; fruit
Other Foods: fungus
Primary Diet: omnivore
While they are a source of food for a number of predators, both native and introduced, the most important role played by Macrotis lagotis is that of an “ecosystem engineer.” Ecosystem engineers are “organisms that modify, maintain, create or destroy structure within the physical environment” (Eldridge and James, 2007). As greater bilbies forage for bulbs, seeds, and insects, they dig pits up to 25 cm deep that are then abandoned. These pits become areas where seeds, water, and other organic matter settle and begin to decompose. Greater bilby pits become “fertile patches” in the Australian desert where some seeds are provided the extra fertilization to germinate in an otherwise extremely difficult environment. Studies compared environments without greater bilbies and a similar, native fossorial group, bettongs (Bettongia) to those where these two native species are present. It was concluded that environments without these native fossorial animals suffered from devastating losses of native Australian fauna despite the presence of rabbits, which also dig burrows.
Greater bilbies were once a favorite traditional food and source of fur for Aboriginal peoples of Australia. The rarity and protected status of greater bilbies means this practice has been all but abandoned. Greater bilbies are promoted as a mascot for the Commonwealth of Australia Endangered Species Program. They are also replacing rabbits as the Australian symbol of Easter, with chocolate bilbies are being sold as an alternative to chocolate bunnies.
Positive Impacts: food ; body parts are source of valuable material
Greater bilbies are listed as Vulnerable on the IUCN red list, endangered under the U.S. Endangered Species List, and are on Appendix I of CITES. The conservation status in each of the Australian territories is as follows: Queensland - extinct, Northern Territory - threatened, Western Australia - vulnerable, South Australia - endangered, New South Wales - presumed extinct. Greater bilbies are the only extant member of Thylacomyidae after their closest relative, lesser bilbies (Macrotis leucura), became extinct between the 1930's and 1960's. Like M. leucura, greater bilbies have suffered a significant drop in population over the past 200 years due to the introduction of invasive predators such as dingos, red foxes, and feral cats, and invasive herbivores such as European rabbits. Along with the introduction of invasive species, a number of new diseases have also been brought to Australia. Greater bilbies are highly susceptible to the parasites and diseases of introduced animals and are commonly infected when they come into contact with feces of introduced species while digging. Without immunities to fight these parasites and diseases, many die as a result. The introduction of both European rabbits and livestock has greatly reduced the abundance of grasses, seeds, and other plant matter typically fed upon by native greater bilbies. As well as the reduction of plants through feeding, grazing has also led to the degradation of bilby habitat. Greater bilby habitat is also being destroyed as a result of human development and they are hit by cars along roads. Greater bilbies are protected under Australian law. A number of breeding and reintroduction projects are underway, as well as projects to control populations of harmful invasive species. Since the 1990's, greater bilby conservation groups have promoted the idea of replacing the Easter Bunny with the Easter Bilby. Chocolate shops around Australia began selling chocolate bilbies with a portion of the profit going to help fund bilby conservation. Greater bilbies have their own Australian holiday, National Bilby Day, anually held in mid-September in hopes of raising funds and educating the public on bilby conservation.
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: vulnerable
Greater bilbies have poor eyesight and mainly rely on hearing and olfaction for perceiving their environment. They have a keen sense of smell, which is used to sniff out food buried underground as well as perceive scent markings of other individuals. With their enormous ears, greater bilbies also listen for insects underground as well as predators. However, hearing seems much less important than olfaction. The ears of greater bilbies are also used to help regulate body temperature. Communication between males usually occurs through scent markings. Males mark the outside of their burrows by rubbing their urogenital area along the burrow entrance. Males may also mark burrows where they have mated with a female. Scent marking seems directly correlated to dominance; dominant males mark over areas less dominant males have previously marked. Also, less dominant males tend to avoid entering burrows of dominant males. Females rarely scent mark their territories. Scent marks by males have little effect on the females since males are rarely, if ever, aggressive towards females.
Communication Channels: chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
Greater bilbies have a polygynous mating system in which the most dominant male will mate with the most dominate female and additional females while lower males will mate with females equal or below them in the social hierarchy. Males initiate sexual interactions by approaching and following a female. This is followed by the male sniffing the female around her face, shoulders, flanks, or under the tail as well as licking the female’s urogenital opening. Females may also sniff the male. Females may aggressively rebuff the advances of lower-ranked males. Copulation seems to take place underground with the longest mating sessions recorded taking place for around 18 hours. There is no evidence of pair bonding, though males will often scent mark the burrow after mating with a female. This is thought to ward off lower-ranked males. These results were observed in a study of captive bilbies. Little has been recorded about bilby mating in the wild due to their decreasing numbers and semi-fossorial, nocturnal lifestyle.
Mating System: polygynous
Greater bilbies have the ability to breed throughout the year, whether breeding occurs depends on environmental conditions. In their arid environments, females may delay mating until conditions are appropriate to support the nutritional demands of lactation and independence of the young. When environmental conditions are favorable, a female bilby may produce up to 4 litters a year, each typically consisting of 1 to 2 offspring, though up to 4 offspring have been reported. Female greater bilbies reach sexual maturity at around 5 months old (or 560 g) while males take around 8 months (or at a weight of 800 g) to reach maturity. The female oestrus cycle lasts around 21 days. Greater bilbies have one of the shortest gestation periods of all mammals, only 14 days. After gestation, the tiny, premature offspring climbs into its mother's pouch, attaches itself to a nipple and remains in the pouch for around 75 days. The young are cared for by the mother for an additional 14 days. After that, the young will leave their mother's burrow and be left to fend for themselves.
Breeding interval: Greater bilbies have up to four litters a year.
Breeding season: Breeding may occur throughout the year.
Range number of offspring: 1 to 4.
Average number of offspring: 1-2.
Average gestation period: 14 days.
Average weaning age: 75 days.
Average time to independence: 14 days.
Average age at sexual or reproductive maturity (female): 5 months.
Average age at sexual or reproductive maturity (male): 8 months.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average gestation period: 17 days.
Average number of offspring: 2.
Average age at sexual or reproductive maturity (female)
Sex: female: 150 days.
Females are the only caregivers of young. After their short gestation, young greater bilbies climb into their mother’s pouch where they remain for the majority of their time with their mother. During the 75 days the young bilbies remain in the pouch, the babies continue to grow at a very fast rate, reaching 200 g by the time they leave the pouch. While in the pouch, the offspring obtain all of their nourishment from mother’s milk. Bilby females have nipples both deep inside the pouch and nipples that hang outside the pouch. Each type of nipple provides a different type of milk for the offspring living outside the pouch versus inside the pouch. Once the young emerge from their mothers pouch, they do not return. Many times, the female has already mated and a new neonate enters the pouch soon after the previous litter has left. These young juveniles are cached by the mother in one of her burrows where she returns regularly over the next two weeks to allow her babies to suckle. After these two weeks, the young leave the burrow and must fend for themselves with no additional parental care. It is estimated that only 25% of offspring produced will reach adulthood while the rest will become prey for predators or succumb to the elements.
Parental Investment: altricial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female)
The Gibson Desert is an ecoregion in Western Australia, which is in the Deserts and Xeric Shrublands biome classification. The land area covered by this ecoregion amounts to 60,200 square miles. A number of mammals, birds and reptiles occur within the Gibson Desert ecoregion, including five taxa iclassified as threatened. Most of the human population within the Gibson Desert are aboriginal peoples.
Major expanses of the Gibson Desert are characterized by gravel-covered topography covered in sparse desert grasses; furthermore, the arid ecoregion sports vast areas of undulating red sand plains and dunefields, low-lying rocky to gravelly ridges and sizeable upland [laterite] soil areas. The sandy soil of the lateritic buckshot plains is particularly high in iron content. Several isolated saline lakes occur in the centre of the region, and at the southwest a series of smaller lakes follow ancient paleo-drainage features. Groundwater resources include elements of the Officer Basin and Canning Basin. Annual precipitationwithin the Gibson Desert can vary from 200 to 250millimeters. The climate is typically hot, with austral summer maximum temperatures rising above 40 degrees Celsius
There are 362 vertebrate species present in this ecoregion, including a number of birds, reptiles and mammals.There are five threatened species present within the Gibson Desert, although species endemism is low. Threatened mammals found in the Gibson Desert are the: Vulnerable greater bilby (Macrotis lagotis) and the Near Threatened rock wallaby (Petrogale lateralis),.Two notable avafauna species present in the Gibson Desert are the Near Threatened Alexandra's parrot (Polytelis alexandrae) and the Near threatened Australian bustard (Ardeotis australis). The woma (Aspidites ramsayi) is an endangered species of reptile occurring here.
The greater bilby, or simply bilby, (Macrotis lagotis) is a long-eared, rabbit-like mammal native to Australia. It lives in burrows and is active at night, feeding on insects, fruit, or fungi. The bilby is a marsupial and carries its young in a pouch. Threats include habitat loss, disease, and introduced predators such as foxes. Formerly widespread, bilbies are now restricted to arid parts of northwestern and central Australia.
It is commonly called bilby after the lesser bilby (Macrotis leucura) became extinct in the 1950s. Other names include dalgyte, pinkie, or rabbit-eared bandicoot.
The term bilby is a loan word from the Yuwaalaraay Aboriginal language of northern New South Wales, meaning long-nosed rat. It is also known as dalgyte in Western Australia by the Noongar people.[4][5] The Wiradjuri of New South Wales also call it bilby.[6] Other names include pinkie and rabbit-eared bandicoot.[7]
A scientific description of the greater bilby was first published in 1837 by a Mr J. Reid. Reid based his description on a specimen that he erroneously stated to have come from Van Diemen's Land (now Tasmania), where the species has not occurred in historical times.[8] As all bandicoot species were then placed in a broadly circumscribed Perameles,[9] Reid placed the bilby there too. However, noting how different it was from other members of the genus, he added that "should more of the same form be discovered, the above characters would constitute a subgenus to which the name of Macrotis might be applied". The specific epithet lagotis was chosen "from its resemblance to the Rabbit".[10]
The following year, Richard Owen read a paper before the Zoological Society of London, in which he proposed to erect a new genus for this species, named Thylacomys.[11] This name was widely adopted and remained in use for many years. Thus it was that when B. Arthur Bensley erected a subfamily to hold the genus in 1903, he named it Thylacomyinae.[12] This name remains valid, and has since been promoted to family rank as Thylacomyidae, but Thylacomys itself is no longer considered valid, as Reid's original paper is held to have established the generic name Macrotis. Thus the currently accepted scientific name for the species is Macrotis lagotis.
The placement of bilbies within the Peramelemorphia has changed in recent years. Vaughan (1978) and Groves and Flannery (1990) both placed this family within the family Peramelidae. Kirsch et al. (1997) found them to be distinct from the species in Peroryctidae (which is now a subfamily in Peramelidae). McKenna and Bell (1997) also placed it in Peramelidae, but as the sister of Chaeropus in the subfamily Chaeropodinae.[13]
Greater bilbies have the characteristics of long bandicoot muzzle and very long ears. They are about 29–55 centimetres (11–22 in) in length. Compared to bandicoots, they have a longer tail, bigger ears, and softer, silky fur. The size of their ears allows them to have better hearing as well. At 1 to 2.4 kilograms (2.2 to 5.3 lb), the male is about the same size as a rabbit; although male animals in good condition have been known to grow up to 3.7 kilograms (8.2 lb) in captivity. The female is smaller, and weighs around 0.8 to 1.1 kilograms (1.8 to 2.4 lb). Bilbies have an excellent sense of smell and sharp hearing. Their fur is blue-grey with patches of tan and is very soft. The tail is black and white with a distinct crest.
Unlike bandicoots, they are excellent burrowers and can build extensive tunnel systems with their strong forelimbs and well-developed claws. A bilby typically makes several burrows within its home range, up to about a dozen; and moves between them, using them for shelter both from predators and the heat of the day. The female bilby's pouch faces backward, which prevents her pouch from getting filled with dirt while she is digging.
Once widespread in arid, semi-arid and relatively fertile areas covering 70 per cent of mainland Australia,[14] by 1995 the bilby was restricted to arid regions and classed as a threatened species.[15] Before the extreme contraction of its range to remote northern desert areas, the species was well known around Adelaide, especially in the city parklands,[16][17] and it was also recorded as living around Perth.[18]
It makes its home in a burrow that spirals down, making it hard for its predators to get in. The bilby prefers arid habitats because of the spinifex grass and the acacia shrubs.[19]
Greater bilbies are nocturnal omnivores that do not need to drink water, as they get all the moisture they need from their food, which includes insects and their larvae, seeds, spiders, termites, bulbs, fruit, fungi, and very small animals. Most food is found by digging or scratching in the soil, and using their very long tongues.[20]
Greater bilbies are generally solitary marsupials; however, there are some cases in which they travel in pairs. These pairs usually consist of two females, and these females are the sole caregivers of their offspring. Mating occurs between pairs of similar dominance, with females rebuffing lower-ranked males.[21] Much of the plant diet of the bilby is facilitated by fires that occasionally run through Australian regions and facilitate the regrowth of plants that the bilby prefers. They are also a highly motile species when it comes to foraging, with females travelling on average 1.5 km between burrows and male travelling up to 5 km. The difference in male and female motility is most likely due to the fact that males are often in search of mates and need to only care for themselves, while females are responsible for their offspring and must work to support them.[22] Communication remains difficult between bilbies due to poor eyesight, but since these marsupials usually live alone or in very small groups, this obstacle is not incredibly formidable. Any communication that does occur is mostly olfactory between males or auditory. The scent markings implemented by male bilbies primarily function as a mode of communication between members of the same sex, since female bilbies rarely take heed of such signals and males are never aggressive towards their female counterparts.[21]
In captivity, bilbies typically live for at least six years with some specimens reaching ten years of age.[23] However, wild caught bilbies tend to be less than 12 months old.[24] Females become reproductively active at six months of age and can breed all year round if conditions are favourable.[25]
Greater bilbies have a very short gestation period of about 12–14 days, one of the shortest among mammals.[20] The young are only 0.25 in (0.6 cm) long and very underdeveloped when they are born. They must crawl to the mother's pouch and latch onto one of her eight teats. They leave the pouch after 70–75 days and remain in the natal burrow for two to three weeks before becoming independent.[26] Litters usually consist of one to three joeys and females can have up to four litters per year in favourable conditions.[24]
Greater bilbies are a vulnerable species as classified by IUCN, their existence threatened by habitat loss and change as well as the competition with other animals. The main threats are cited as "Livestock farming & ranching" and "Invasive non-native/alien species/diseases". However, the biggest threat to the bilby is believed to be predation by introduced predators, notably foxes,[1] with changing fire regimes and pastoralism being landscape-scale variables that also impact bilby distribution and population. There is a national recovery plan for saving these animals: this program includes breeding in captivity, monitoring populations, and re-establishing bilbies where they once lived.[1]
The species is also listed as vulnerable under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999, with a species recovery plan published in 2007. Under state and territory legislation, it is extinct in New South Wales, endangered in Queensland, and vulnerable in the Northern Territory, South Australia and Western Australia.[27]
Save the Bilby Fund CEO Kevin Bradley estimated in December 2021 that the animal had been pushed back to around 10% of their former range, which covered 70% of Australia.[28]
The bilby has been popularised as a native alternative to the Easter Bunny by selling chocolate Easter Bilbies. Haigh's Chocolates in Adelaide made 950,000 chocolate bilbies between 1993 and Easter 2020, with proceeds donated to the Foundation for Rabbit-Free Australia, which does environmental work to protect the indigenous biodiversity of Australia.[29] A National Bilby Day is held in Australia on the second Sunday in September to raise funds for conservation projects.[30][31]
Reintroduction efforts have been successful in South Australia, with 16 bilbies released onto Thistle Island in 1997,[32] and 9 released into the Arid Recovery Reserve near Roxby Downs in 2000.[33] The Arid Recovery population's gene pool has been expanded by two additional releases in 2010 and 2020, the latter from the thriving population on Thistle Island.[34] From 2001 to 2003, 19 bilbies were introduced into the Venus Bay Conservation Park at Venus Bay on the Eyre Peninsula.[32] Bilbies have been bred at Monarto Zoo[32] and (since 2009) at Cleland Wildlife Park.[35]
Bilbies were also introduced into the Currawinya National Park in Queensland,[36] with six bilbies released into the feral-free sanctuary in early February 2006. In July 2012 it was reported that the population at Currawinya has been affected by feral cats that had gained access into the protected area after the wire netting had rusted after flooding.[37] The high-salinity flood water had pooled around sections of the fencing, and once parts of it had rusted the cats had entered the reserve through the holes. Surveys found no bilbies in April nor July, when the cats were discovered.[38] As of July 2015 there were 75 bilbies ready to be released into the enclosure, but with at least six cats remaining after around 30 were culled, release was being held back.[37]
The Charleville Bilby Experience at Charleville, Queensland, run by the Save the Bilby Fund, has a breeding program, with the first set of twins born in December 2021. Babies born here are sometimes transferred to Currawinya.[28]
Successful reintroductions have also occurred onto Peron Peninsula in Western Australia as a part of[39] Western Shield. Successful reintroductions have also occurred on other conservation lands, including islands and the Australian Wildlife Conservancy's[40] Scotia[41] and Yookamurra Sanctuaries.[42] There is a highly successful bilby breeding program at Kanyana Wildlife Rehabilitation Centre,[43] near Perth.
The knowledge of the Martu people of the Western Desert has been incorporated into models that predict bilby distributions.[44]
The greater bilby, or simply bilby, (Macrotis lagotis) is a long-eared, rabbit-like mammal native to Australia. It lives in burrows and is active at night, feeding on insects, fruit, or fungi. The bilby is a marsupial and carries its young in a pouch. Threats include habitat loss, disease, and introduced predators such as foxes. Formerly widespread, bilbies are now restricted to arid parts of northwestern and central Australia.
It is commonly called bilby after the lesser bilby (Macrotis leucura) became extinct in the 1950s. Other names include dalgyte, pinkie, or rabbit-eared bandicoot.