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. Taxonomy 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. 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. Gould obtained his specimens while in Australia, returning these to England for scientific examination; he gave the animal the common name bridled kangaroo. Description 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. 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. Ecology and behaviour The species 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 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