No information on anti-predator adaptations was available for O. fraenata. Native dingoes may be predators of these animals. Exotic carnivores such as red foxes may prey on these animals.
Known Predators:
Onychogalea fraenata is named for the white "bridle" line that starts on the center of the neck and goes around the shoulders and ends at the forearms on each side. A black stripe runs dorsally across the whole body.
Males weigh between 5 and 8 kg, whereas females weigh from 4 to 5 kg. The head and body length of this species is 430 to 700 mm, with the tail contributing an additional 360 to 730 mm to the total length.
The genus Onychogalea gets its common name, nail tailed wallabies, from a small, horny spur (3 to 6 mm) at the end of the tail. This "nail" is partially concealed by hair.
Range mass: 4 to 8 kg.
Range length: 790 to 1,430 mm.
Sexual Dimorphism: male larger
Other Physical Features: endothermic ; bilateral symmetry
Not much information is available regarding the lifespan/longevity of this species. However, individuals in captivity have lived 5.5 years.
Range lifespan
Status: captivity: 5.5 (high) years.
Average lifespan
Status: captivity: 7.4 years.
At one time, Onychogalea fraenata inhabited the semi-arid region of eastern Australia. This region is made up mainly of Acacia shrub land and grassy woodlands. Now it is only found in Taunton National Park although a population has recently been released into Idalia National Park.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; scrub forest
The range of endangered bridled nail-tailed wallabies has been reduced to 11,470 hectares in the Taunton Scientific Reserve in northeastern Austalia. This reserve is located near the city of Dingo in Central Queensland.
Biogeographic Regions: australian (Native )
Very little information was available on communication in O. fraenata. However, some generalizations can be made, based on what we know of mammals in general, and other macropods in particular.
These animals are known to transmit information through scent cues, especially when females are in estrous. Males determine the readiness of females to mate based upon their smell. In addition, there is some visual and tactile communication during mating, based upon chasing behavior and the mating process itself.
Other macropods are known to vocalize, and it is likely that O. fraenata is similar.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Onychogalea fraenata is part of a large recovery plan. The number of these wallabies has declined due to competition with domestic animals, habitat destruction, and the introduction of carnivores (mainly foxes and dingos). Onychogalea fraenata has already been successfully reintroduced into the Idalia National Park and there are plans for other reintroductions from animals in captive breeding programs. The species is listed as Endangered by IUCN and is on Appendix I of CITES.
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: endangered
This species has little effect on humans.
Because nail-tailed wallabies are only found in national parks, they may be important for ecotourism.
Positive Impacts: ecotourism
Onychogalea fraenata feed on a variety of plants and may affect plant communities in then region.
Onychogalea fraenata feeds on a diverse selection of forbes, grasses, and woody browse. During observation in Taunton National Park, these foods were selected by the animals: The herbaceous forb Portulaca oleraceae, pigweeds such as Helipterum spp., daisies such as Trianthema triquetra and Zalea galericulata, and grasses such as Sporobolus carolii, Chloris divaricata, Dactyloctenium radulans, and Bothriochloa bladhi.
Plant Foods: leaves
Primary Diet: herbivore (Folivore )
Onychogalea fraenata mates polygynously. Males roam widely, checking nonestrus females briefly by smell. They may accompany estrus females that they encounter for up to a week. Groups of males sometimes accumulate around receptive females. These males follow females roughly in order of body weight, and the largest male appears to defend access to the female.
The main difference between O. fraenata and most other terrestrial macropods is that there is no dominance hierarchy prior to encounter. Because O. fraenata is solitary, males cannot establish dominance relationships until they have encountered one another. However, these animals can recognize dominance from prior encounters, so rather than waste energy on another combat sequence they behave toward one another based upon the hierarchy determined in previousl encounters.
Copulation times may exceed more than ninety minutes, which is longer than most macropods.
During estrus cycles, females increase their home range. They also increase their activity, and are more attractive to males prior to mating. Such features are not unique to this species, but are common in most solitary mammals.
Male that are the largest in size and have the largest home ranges have higher copulatory success. Males and females participate in mate chasing. Because females do not appear to be attempting to evade the males, based on their slow speed and repetitive movements, this appears to be some sort of courtship behavior.
Mating System: polygynous
Onychogalea fraenata has been studied both in captivity and wild. In captivity, these animals breed continuously. Females have an average estrous cycle of 32.6 days and gestation lasts an average 23.6 days. Newborns spend 119 to 126 days in the pouch. Males reach sexual maturity in about 270 days, whereas females reach it in 136 days.
If conditions are suitable in the wild, bridled nailtail wallabies can raise up to three young per year and mate continuously throughout the year.
Breeding interval: Females of this species are capable of producing three offspring per year.
Breeding season: Breeding is not seasonal when conditions are favorable.
Average number of offspring: 1.
Average gestation period: 23.6 days.
Range weaning age: 119 to 126 days.
Average age at sexual or reproductive maturity (female): 136 days.
Average age at sexual or reproductive maturity (male): 270 days.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous
Average gestation period: 23 days.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (female)
Sex: female: 185 days.
Like other macropods, O. fraenata, have extremely altricial young. Young are born excessively underdeveloped, and must complete their delopment inside the mother's pouch, attached to her nipple. Based on the mating system, it is unlikely that there is paretal care provided by males.
Parental Investment: no parental involvement; altricial ; pre-fertilization (Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Protecting: Female)
The bridled nail-tail wallaby (Onychogalea fraenata), also known as the bridled nail-tailed wallaby, bridled nailtail wallaby, bridled wallaby, merrin, and flashjack, is a vulnerable species of macropod. It is a small wallaby found in three isolated areas in Queensland, Australia, and whose population is declining. In early 2019 the total population of the species was estimated to be fewer than 500 mature individuals in the wild and 2285 in captivity.[4]
A specimen was presented to the Linnean Society of London by John Gould in 1840, and published in the society's journal the following year.[3] The date of first publication has been the source of conjecture, and it has been proposed that this was in a 1840 issue of The Athenaeum.[a][5]
Gould obtained his specimens while in Australia, returning these to England for scientific examination; he gave the animal the common name bridled kangaroo.[6]
These small wallabies are named for two distinguishing characteristics: a white "bridle" line that runs down from the back of the neck around the shoulders, and a horny spur on the end of the tail. Other key physical features include a black stripe running down the dorsum of the neck between the scapulae, large eyes, and white stripes on the cheeks, which are often seen in other species of wallabies as well.
The bridled nail-tail wallaby can grow to one metre in length, half of which is tail, and weighs 4–8 kg. Females are somewhat smaller than the males. The tail spur can be 3–6 mm long and partly covered in hair. Its purpose is unclear.[7]
The "nail-tail" is a feature common to two other species of wallabies: the northern nail-tail wallaby and the crescent nail-tail wallaby (which was declared to be extinct in 1956).
The taste of the meat of this species was described by Gould as excellent.[6]
The species are most active during the night-time[8] 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 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.
Gould was able to view the animal in its native habitat and recorded observations of its behaviour at the area around Brezi and then to observe their capture by the indigenous people at "Gundermein" on around the lower Namoi River. His notes the rapid movement of a live animal when pursued, outpacing the dogs accompanying his party, which ascended up a hollow tree and leapt from the top to enter a hollow log. At a second site Gould witnessed the capture of the species with nets by the local people, fulfilling his request for a series of specimens.[6]
After a gestation period of about 23 days, the single joey undergoes further development in the mother's pouch for around four more months.
The bridled nail-tail wallaby's defence behaviour when threatened by native predators is usually to lie flat on the ground and find some cover. However, in 2021 it was observed that in response to introduced predators such as feral cats and foxes, it had altered its behaviour and had learnt to hide in response to smelling the predator.[8]
The bridled nail-tail wallaby is of interest to marsupial researchers because it appears to have a more vigorous immune system than other species of macropods. In the words of marsupial immunologist Dr Lauren Young, "These wallabies appear to be able to survive parasite infections,[9] viruses and various diseases more readily than other marsupials".[10]
At the time of European settlement of Australia, bridled nail-tail wallabies were common all along the East Australian coastline region to the west of the Great Dividing Range. 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.[11][12]
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.[13][14] This sighting was subsequently confirmed by researchers from the Queensland Parks and Wildlife Service, and the property became Taunton National Park[1] in 1973,[8] a scientific nature reserve for the purpose of ensuring the ongoing survival and protection of this endangered species.[1]
As of 2001, the range of this wallaby was estimated at less than 5% of its original range.[15] The extant population was estimated to be fewer than 500 mature individuals in the wild in 2019.[4]
In the early 1900s this species suffered dramatically from shooting, for its fur and because it was considered a pest.[16] Current threats to the species include predation by introduced species such as feral cats, red foxes, and dingoes. Other threats include wildfires, prolonged drought, habitat destruction by the pastoral industry and competition for food from grazers, such as rabbits and domestic sheep.[15]
Since its rediscovery, the bridled nail-tail wallaby has been the target of private conservation efforts to re-establish viable populations. Captive breeding programs established three populations in Queensland: two in State reserves located at Idalia and Taunton National Parks, and another on a private reserve, Project Kial, located near Marlborough in Central Queensland.[4]
After the last captive-breeding facility in Queensland failed, the remaining animals were transferred to Avocet Nature Refuge (south of Emerald), with the total population there and at Taunton estimated at around 600.[17] As of 2019, the species was confined three populations: Taunton and Avocet in Queensland, and Australian Wildlife Conservancy's Scotia Sanctuary in New South Wales, where there were more than 1,000 wallabies in 2018.[17]
In August 2019, 41 Bridled Nailtail Wallabies were scouted from Taunton and Scotia for reintroduction to a feral predator-free breeding area within the Pilliga State Conservation Area in northwestern NSW. The translocation was conducted by Australian Wildlife Conservancy in partnership with NSW National Parks and Services, as part of the NSW Government's Saving our Species program.
A new strategy known as head-starting has been trialled at Avocet, with a successful outcome reported in May 2021: the population had grown by more than 100% over three years. A 10-hectare (25-acre) area had been fenced off three years earlier, with the youngest wallabies placed in it and allowed to grow in an area safe from feral cats, after studies had shown that it was overwhelmingly this group that was most vulnerable to predation. Although this method had been tested on reptiles and birds before, this was its first trial with land-based mammals.[18][19]
At Taunton Conservation Park, a total of 65 of the wallabies were recorded in 2008, but by early 2021, the population had risen to an estimated 1,300.[8]
The bridled nail-tail wallaby (Onychogalea fraenata), also known as the bridled nail-tailed wallaby, bridled nailtail wallaby, bridled wallaby, merrin, and flashjack, is a vulnerable species of macropod. It is a small wallaby found in three isolated areas in Queensland, Australia, and whose population is declining. In early 2019 the total population of the species was estimated to be fewer than 500 mature individuals in the wild and 2285 in captivity.
