Bridled nailtail wallaby
Bridled nailtail wallaby
(Onychogalea fraenata)
Photo: DERM
Common name: bridled nailtail wallaby
Other names: flashjack, merrin, waistcoat wallaby
Scientific name: Onychogalea fraenata (Gr. onyx = nail, gale = weasel, L. fraenum = bridle)
Animal group: wallabies, kangaroos and tree-kangaroos
Conservation status
This species is listed as Endangered in Queensland ( Nature Conservation Act 1992 ) and nationally ( Commonwealth Environment Protection and Biodiversity Conservation Act 1999).
Description
The bridled nailtail wallaby is a small wallaby with males weighing an average of 5-6kg and females 4-5kg. It is grey to light tan in colour with a distinct white line forming a "bridle" from the back of the neck to behind the forelimbs. Its other distinctive markings are the white stripes along the sides of the face, and a black stripe down the length of the back.
There are three species of wallaby that have the characteristic "nail-tail", with a nail-like spur about 3-6mm long at the tip of the tail: the bridled nailtail wallaby, crescent nailtail wallaby (believed to be extinct) and northern nailtail wallaby (common in northern Australia).
Diet of the bridled nailtail wallaby
The preferred diet of the bridled nailtail wallaby is largely non-woody broad-leafed plants, chenopods (succulents including pigweed), flowering plants and grasses. Two potential competitors for this food include the black-striped wallaby (Macropus dorsalis) and domestic stock.
Life history and behaviour
Bridled nailtail wallabies are able to breed at any time, and can potentially have three young a year. The gestation period is around 24 days and young stay in the pouch for around 120 days. They mature at a young age (females at 136 days and males at 270 days), however, it may take up to 18 months before a male is large and strong enough to successfully mate.
The main defence strategy of the bridled nailtail wallaby is to hide rather than flee, which is uncommon in macropods. They are fairly inactive during the day and adults rest and shelter in hollow logs or under young brigalow trees, with females leaving their young-at-foot in low, dense vegetation such as grass tussocks.
It is unknown whether the "nail-tail" spur serves a function, but one theory is that it may aid their speed when the spur hits the ground and acts as a point on which the wallaby pivots during sharp turns. The bridled nailtail wallaby's ability to flee at high speed is how they earned their name "flashjack".
Habitat and distribution
The bridled nailtail wallaby lives in semi-arid areas where dense acacia shrubland and grassy woodland meet. At the time of European settlement this was a common species with a distribution reaching the west of the Great Dividing Range, north to Charters Towers in Queensland, south to north-western Victoria, and possibly extending west to eastern South Australia. The bridled nailtail wallaby now survives in a small percentage of the area it once inhabited.
For over 30 years they were believed to be extinct as there had been no confirmed sightings of individuals since 1937. Then, in 1973, the species was ‘re-discovered’ by a fencing contractor, who after reading an article about Australia's extinct species in a magazine, reported that there was a population of bridled nailtail wallabies on a property in central Queensland near the town of Dingo. This was confirmed by researchers from the Queensland Parks and Wildlife Service and the property eventually became Taunton National Park (Scientific). Current population estimates for Taunton National Park (Scientific), including neighbouring properties, are approximately 200 wallabies.
Re-introductions
New populations of the wallaby have been re-introduced to habitats it once occupied to aid recovery of the species in the wild. In 1994 bridled nailtail wallabies were introduced to Idalia National Park and currently the population is estimated to be approximately 100 wallabies.
During 2001 – 2005, bridled nailtail wallabies were released on to part of Avocet, a large private property south of Emerald. In 2003, this part of the property was gazetted as a Nature Refuge – Avocet Nature Refuge - and is now home to a third population of approximately 100 wallabies.
Captive breeding
Captive populations of bridled nailtail wallabies have been established at a number of locations throughout Queensland since the early 1990’s for the purposes of research and education, and for breeding bridled nailtail wallabies for reintroduction to the wild. These were:
- DERM Pallarenda Research Station from 1991 – 2004;
- DERM David Fleay Wildlife Park from 1992 - 2008;
- Idalia National Park from 1993 – 2004; and
- Gregory Mine Site (Emerald) from 1997 – 2006.
In August 2008, the Department of Environment and Resource Management entered into a Captive Breeding Agreement with Australian Animals Care and Education Inc. (AACE) to aid recovery of this species. Through this program, bridled nailtail wallabies are being bred for release into the wild. To date, there have been 11 births. Sites for release include the two existing reintroduction sites of Idalia National Park and Avocet Nature Refuge.
Threatening processes
Declines in the range and numbers of bridled nailtail wallabies are believed to be from a combination of the following:
- Predation, primarily by foxes and feral cats, and some predation from wild dogs;
- habitat loss, modification and degradation (through land clearing, drought, fire, and buffel grass); and
- competition with introduced stock (mainly sheep) and rabbits.
The Queensland Hunting and Conservation division (H&C) of the Sporting Shooters’ Association of Australia (SSAA) undertake predator control activities at Taunton National Park and Avocet Nature Refuge. The primary target species are foxes and feral cats although dingoes and rabbits are taken as well depending on numbers present. H&C recently received a grant from the Threatened Species Network (TSN) of the World Wide Fund for Nature (WWF) to acquire feral cat traps for use at Avocet Nature Refuge.
Recovery actions
The Recovery Plan recommends the following actions:
- Preserve preferred habitat and increase the existing wild populations.
- Conserve the only known remnant population at Taunton National Park.
- Protect and enhance the two reintroduced populations at Idalia National Park and Avocet Nature Refuge.
- Determine suitable sites for future reintroductions.
- Continue feral predator control programs where appropriate and reduce the threat of fire and buffel grass on existing wild populations.
- Support the current Captive Breeding Agreement.
What can be done to help this species?
Landholders in the areas where bridled nailtail wallabies have been known to occur should report sightings to their local DERM office. As has been done with Avocet Nature Refuge, perpetual conservation agreements can be used to conserve areas of remnant vegetation that provides habitat for bridled nailtail wallabies. Under such agreements, incentives and support are provided to landholders and access to the property can be negotiated.
Research can also help the bridled nailtail wallabies by discovering information that will improve their conservation management. Current research projects undertaken by the University of Queensland are investigating the effects of food quality on different populations, the impacts of introduced predators, and habitat restoration.
A Masters study finished in 2008 by Lisa Kingsley at the University of Queensland evaluated the success of the reintroduced population of bridled nailtail wallaby at Avocet Nature refuge. The study found that the population was doing well, as although there was only a slight increase in the population from 2005 to 2008, the wallabies had good body condition and a lower reproductive failure rate than the population at Taunton National Park.
Further information
Gordon, G. and Lawrie, B.C. (1980). The rediscovery of the bridled nailtail wallaby (Onychogalea fraenata Gould) in Queensland. Australian Wildlife Research 7: 339-345.
Horsup A. and Evans, M. (1993). Predation by feral cats, Felis catus, on an endangered marsupial, the bridled nailtail wallaby, Onychogalea fraenata. Australian Mammalogy 16(1): 85-86.
Johnson, P.M. (2003). Kangaroos of Queensland. Queensland Museum, Brisbane.
Lavery, H.J. and Tierney, P.J. (1985). 'Scarcity and extinction', in H.J. Lavery (ed.), The Kangaroo Keepers. University of Queensland Press, St Lucia.
Lundie-Jenkins, G. and Lowry, J. 2005. Recovery plan for the bridled nailtail wallaby (Onychogalea fraenata) 2005-2009. Report to the Department of Environment and Heritage (DEH), Canberra. Environmental Protection Agency/Queensland Parks and Wildlife Service, Brisbane.
Last updated: 03 September 2009