Bridled Nail-tail Wallaby
Encyclopedia
Bridled Nail-tail Wallaby refers to Onychogalea fraenata, an endangered species
of marsupial
. It is a small wallaby
found in three isolated areas in Queensland
, Australia
, and whose population is declining. Estimations place the present total population of the species at around 500 individuals.
Key physical features are the bridle markings, a black dorsal stripe and the tail spur. Other markings include stripes on their cheeks, which is often seen in other species of wallabies as well. The tail spur can be 3–6 mm long and partly covered in hair. Its purpose is unclear.
The "nail-tail" is a feature common to two other species of wallabies, the Crescent Nail-tail Wallaby
and the Northern Nail-tail Wallaby
. While the Crescent Nail-tail was declared extinct in 1956, the Northern Nail-tail wallaby still exists in steady populations in northern Queensland and the Northern Territory.
The wallabies are most active during the night-time and dusk periods. Day is usually spent sleeping in hollows near bushes or trees. In modern habitats, Nail-tails keep close to the edges of pasture grasses.
These wallabies have a strong reputation as shy and solitary animals. They may occasionally form small groups of up to four to feed together when grazing is in short supply.
The Bridled Nail-tail Wallaby likes to avoid confrontation and has two main ways of avoiding threats – hiding in hollow logs and crawling under low shrubs. If caught in the open, it may try to lie completely still hoping not to be observed.
Joeys are brought up in the mother's pouch
. One young is born at a time and availability of food sources determine how often they breed. The gestation
period is about 23 days and the joey stays in the pouch for around four months.
. Naturalists in the 19th century reported that the species ranged from the Murray River
region of Victoria
through central New South Wales
to Charters Towers in Queensland
.
The species declined in the late 19th and early 20th centuries with no confirmed sightings between 1937 and 1973, by which time it was believed to be extinct. After reading an article in a magazine about Australia's extinct species, a fencing contractor reported that there was an extant population on a property near Dingo, Queensland.
to re-establish viable populations. Captive breeding
programs have allowed the establishment of three populations; two in State reserves located at Idalia
and Taunton National Park
s, and another on a private reserve, Project Kial, located near Marlborough
in the Central Queensland
region. There are an estimated 400–600 individuals.
Major threats to the species are predation by introduced species
, namely feral cats and fox
es. Protecting habitats from these predators is key to maintaining reserve populations.
appearing to possess a hardier constitution than other species of marsupial
s. In the words of Central Queensland University
based marsupial immunologist Lauren J Young, "These wallabies appear to be able to survive parasite infections, viruses and various diseases more readily than other marsupials".
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
of marsupial
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
. It is a small wallaby
Wallaby
A wallaby is any of about thirty species of macropod . It is an informal designation generally used for any macropod that is smaller than a kangaroo or wallaroo that has not been given some other name.-Overview:...
found in three isolated areas in Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, and whose population is declining. Estimations place the present total population of the species at around 500 individuals.
Description
The small wallaby is named for its three distinguishing characteristics; a white "bridle" line that runs down from the back of the neck around the shoulders, and the horny spur on the end of its tail. Its common name is in the variant Bridled Nail-tailed Wallaby, and archaically Flashjack. The Bridled Nail-tail Wallaby can grow to 1 meter in length, half of which is tail, and weighs 4–8 kg. Females are somewhat smaller than the males.Key physical features are the bridle markings, a black dorsal stripe and the tail spur. Other markings include stripes on their cheeks, which is often seen in other species of wallabies as well. The tail spur can be 3–6 mm long and partly covered in hair. Its purpose is unclear.
The "nail-tail" is a feature common to two other species of wallabies, the Crescent Nail-tail Wallaby
Crescent Nail-tail Wallaby
The Crescent Nail-tail Wallaby was a nail-tail wallaby that lived in the woodlands and scrubs of the west and centre of Australia. It had silky fur and, like other nail-tail wallabies, had a horny spur at the tip of its tail. It was the size of a hare and was the smallest nail-tail wallaby at...
and the Northern Nail-tail Wallaby
Northern Nail-tail Wallaby
The Northern Nail-tail Wallaby , also known as the Sandy Nail-tail Wallaby, is a species of macropod found in Queensland, Western Australia and Northern Territory. Unlike the Bridled Nail-tail Wallaby , the Northern Nail-tail Wallaby is not a threatened species. The only other member of the genus,...
. While the Crescent Nail-tail was declared extinct in 1956, the Northern Nail-tail wallaby still exists in steady populations in northern Queensland and the Northern Territory.
The wallabies are most active during the night-time and dusk periods. Day is usually spent sleeping in hollows near bushes or trees. In modern habitats, Nail-tails keep close to the edges of pasture grasses.
These wallabies have a strong reputation as shy and solitary animals. They may occasionally form small groups of up to four to feed together when grazing is in short supply.
The Bridled Nail-tail Wallaby likes to avoid confrontation and has two main ways of avoiding threats – hiding in hollow logs and crawling under low shrubs. If caught in the open, it may try to lie completely still hoping not to be observed.
Joeys are brought up in the mother's pouch
Pouch (marsupial)
The pouch is a distinguishing feature of female marsupials ; the name marsupial is derived from the Latin marsupium, meaning "pouch". Marsupials give birth to a live but relatively undeveloped fetus called a joey. When the joey is born it crawls from inside the mother to the pouch...
. One young is born at a time and availability of food sources determine how often they breed. The gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period is about 23 days and the joey stays in the pouch for around four months.
History
At the time of European settlement, Bridled Nail-tail Wallabies were common all along the East Australian coastline region to the west of the Great Dividing RangeGreat Dividing Range
The Great Dividing Range, or the Eastern Highlands, is Australia's most substantial mountain range and the third longest in the world. The range stretches more than 3,500 km from Dauan Island off the northeastern tip of Queensland, running the entire length of the eastern coastline through...
. Naturalists in the 19th century reported that the species ranged from the Murray River
Murray River
The Murray River is Australia's longest river. At in length, the Murray rises in the Australian Alps, draining the western side of Australia's highest mountains and, for most of its length, meanders across Australia's inland plains, forming the border between New South Wales and Victoria as it...
region of Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
through central New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
to Charters Towers in Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
.
The species declined in the late 19th and early 20th centuries with no confirmed sightings between 1937 and 1973, by which time it was believed to be extinct. After reading an article in a magazine about Australia's extinct species, a fencing contractor reported that there was an extant population on a property near Dingo, Queensland.
Recovery efforts
Since its rediscovery, the Bridled Nail-Tail has been the target of private conservation effortsWildlife conservation
Wildlife conservation is the preservation, protection, or restoration of wildlife and their environment, especially in relation to endangered and vulnerable species. All living non-domesticated animals, even if bred, hatched or born in captivity, are considered wild animals. Wildlife represents all...
to re-establish viable populations. Captive breeding
Captive breeding
Captive breedingis the process of breeding animals in human controlled environments with restricted settings, such as wildlife reserves, zoos and other conservation facilities; sometimes the process is construed to include release of individual organisms to the wild, when there is sufficient...
programs have allowed the establishment of three populations; two in State reserves located at Idalia
Idalia National Park
Idalia is a national park in Queensland , 893 km west of Brisbane. Idalia National Park is located near the town of Blackall in the Queensland outback. The park protects 144,000 hectares of mulga lands with conservation value...
and Taunton National Park
Taunton National Park
Taunton is a scientific national park in Australia, 130 km west of Rockhampton, Queensland....
s, and another on a private reserve, Project Kial, located near Marlborough
Marlborough, Queensland
Marlborough is a small township located north west of the city of Rockhampton in central Queensland, Australia. The town is administered by the Rockhampton Regional Council, and lies on the Bruce Highway...
in the Central Queensland
Central Queensland
Central Queensland is an ambiguous geographical division of Queensland that centres on the eastern coast, around the Tropic of Capricorn. Its major regional centre is Rockhampton and the Capricorn Coast and the area extends west to the Central Highlands at Emerald, north to the Mackay Regional...
region. There are an estimated 400–600 individuals.
Major threats to the species are predation by introduced species
Invasive species in Australia
Invasive species are a serious threat to the native biodiversity of Australia and are an ongoing cost to Australian agriculture.Management and the prevention of the introduction of new invasive species are key environmental and agricultural policy issues for the Australian federal and state...
, namely feral cats and fox
Fox
Fox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids , characterized by possessing a long narrow snout, and a bushy tail .Members of about 37 species are referred to as foxes, of which only 12 species actually belong to...
es. Protecting habitats from these predators is key to maintaining reserve populations.
Scientific significance
The Bridle Nail-Tail wallaby is of interest to marsupial researchers due to its immune systemImmune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
appearing to possess a hardier constitution than other species of marsupial
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
s. In the words of Central Queensland University
Central Queensland University
CQUniversity is an Australian public university based in Queensland. Its main campus is in North Rockhampton Queensland. However, it also has campuses in Bundaberg, Emerald, Gladstone and Mackay, as well as operations throughout Asia-Pacific. For instance, Melior Business School is one of its...
based marsupial immunologist Lauren J Young, "These wallabies appear to be able to survive parasite infections, viruses and various diseases more readily than other marsupials".
External links
- Species Profile and Threats Database: Onychogalea fraenata — Bridled Nail-tail Wallaby, Department of the Environment, Water, Heritage and the Arts.
- Bridled Nailtail Wallaby Trust
- Project Kial, A Bridled Nailtail Wallaby Recovery Project, Australian Animals Care & Education Inc (AACE)