There are fifteen known species of rock wallabies including P. concinna. Petrogale concinna has a variety of names such as the Nabarlek and little pigmy rock wallaby. It was discovered in 1842 by a gentleman by the name of Gould.
Marsupials are rarely vocal. When they are used, vocalizations play a role primarily in mating, territorial, and mother to young encounters. Captive Petrogale concinna displayed vocalization during adult female encounters. Using vocalization establishes dominance among females. Vocalization was nearly always given by the defending animal, with each call appearing to have different functional significances. Threat calls are screams, given in response to an attack; sneezes are given at intermediate distances in response to movements of the opponent; coughs are threat calls given in response to an approach; barks are hesitant calls that are generally given at long distances.
Communication Channels: tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Although Petrogale concinna is not listed as being threatened it is found on two of Australia's conservation reserves; Kakadu and Litchfield National Parks.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: data deficient
No known negative economic importance.
Little is known about Petrogale concinna.
Positive Impacts: research and education
Members of this species are herbivores. They may play a role in determining the structure of plant communities.
Ecosystem Impact: disperses seeds
Petrogale concinna does not stray far from the safety of its rock shelter, except that at night it may travel far distances to feed on grasses, sedges and ferns. During the dry season this species relies on a fern Marsilea crenata, feeding primarily on grasses during the wet season.
Unlike most macropodids, adult P. concinna lack a specialized structure called a gastric sulcus. This structure is found in most herbivores that have modified stomachs for microbial fermentation of food, and facilitates movement of liquid digesta. Captive P. concinna were seen frequently regurgitating food. According to Goldstone and Nelson “this behavior is not analogous to rumination in ruminants and has been termed mercyism”.
Plant Foods: leaves; roots and tubers
Primary Diet: herbivore (Folivore )
Petrogale concinna is found only in the Northern Territory of Australia and a few neighboring islands (Borda, Augustus, Long and Hidden).
Biogeographic Regions: australian (Native )
Petrogale concinna is restricted to the sandstone or granite rocky hills, cliffs and gorges of northern Australia.
Range elevation: 300 to 600 m.
Habitat Regions: tropical
Terrestrial Biomes: savanna or grassland
The maximum known lifespan of Petrogale concinna is 17 years.
Average lifespan
Status: captivity: 11.7 years.
Petrogale concinna has dull, reddish colored fur with light grey and black marbling. The belly is greyish-white. The tip of tail is black and bushy. The fur is short with a soft, silky texture. The soles of the feet are thickly padded and granulated in order to grip rock; these animals use skin friction rather than large claws to climb. Body size varies among individuals. Head and body length can range from 310-365 mm; the tail can range 260-335mm; hind feet can be 95-105 mm; ear length can be 41-45 mm; and weight can range from 1200-1600g g.
The teeth of Petrogale concinna are unique among marsupials. Throughout life, the molars of P. concinna continually erupt. The old molars are pushed forward until they eventually fall out in the front of the mouth. The actual number of molars is unknown. As many as nine molars can successively erupt, but there are seldom more than five molars in place at any time. Researchers believe this phenomenon could be an adaptation to the ferns that they eat, because fern tissue is extremely abrasive.
As Petrogale concinna runs, it carries its body horizontally with its tail arched high over its back.
Range mass: 1200 to 1600 g.
Range length: 310 to 365 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
Current threats to P. concinna include habitat change by altered fire regimes and possible attacks by feral cats.
Known Predators:
Little is known about this species in the wild. Captive Petrogale concinna females are known to attack males after mating by kicking and bites to the back of head and neck. If the male was not removed, he would be killed.
Captive Petrogale concinna breed throughout the year, and post-partum estrus and embryonic diapause occur. The estrous cycle lasts from an average of 31-36 days. Dominant females posess a shorter estrous cycle than subordinant females. Females have one offspring per litter and gestation lasts roughly thirty days. The time to weaning in P. concinna is much shorter than that of the other species in its genus. After 160 days outside of the pouch, the joey is completely weaned and, in 175 days, it is independent.
Breeding season: Breeding occurs continually throughout the year.
Average number of offspring: 1.
Average gestation period: 30 days.
Average weaning age: 160 days.
Average time to independence: 175 days.
Average age at sexual or reproductive maturity (female): 2 years.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous ; embryonic diapause ; post-partum estrous
Average gestation period: 30 days.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (female)
Sex: female: 430 days.
Females nurse and care for their young until they reach independence. Once the young are weaned, mothers do not tolerate their continued presence. Females drive off young when they attempts to suckle. They may bite at the tail of the young, occasionally causing the tail to become lost due to irritation caused by bites.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
Nabarleks (Petrogale concinna), are a tiny species of macropod found in northern Australia. They are a shy and nocturnal animal that resides in rocky hollows and forages in the surrounding area. Their diet is grasses, sedges, and ferns found in and around their scrub covered refuges. They are distinguished by a reddish tinge to the mostly grey fur and a distinct stripe at the cheek. They move with great speed and agility when observed, with a forward leaning posture and a bushy tail that arches over the back.
The name comes from the Kunwinjku language of West Arnhem Land.[3] The animal has also lent its name to the well known rock group from the area, Nabarlek.
John Gould presented a description of this species to the Zoological Society of London in 1842, which was published in its Proceedings and introduced by the presiding chair William Yarrell as "two new species of Kangaroo".[2][4] The affinities of the species have been recognised in several ways, including an arrangement that sees it placed with the 'brachyotis species group'. Other authors had separated this species to a new genus Peradorcas, producing a new combination Peradorcas concinna, although the revision by D. J. Kitchener of Petrogale did not recognise this treatment and this is maintained by other authorities. The locality of the type specimen is Wyndham, Western Australia.[4] The specimen was collected and brought to England on the voyage of HMS Beagle.[2]
Nabarlek is most closely related to the monjon and to the short-eared rock-wallaby Petrogale brachyotis. It was formerly considered distinct enough to be assigned its own genus, Peradorcas but it is now considered to belong, like the rest of the rock-wallabies, in the genus Petrogale.[4]
The common name designated for a similar species, monjon for P. burbidgei, is also used to refer this species in the Kimberley region; the two species are however known to be distinct by the indigenous people from whose language the name derives.[5] Common names for the species include the little rock-wallaby[6][7] or pygmy rock-wallaby.
Three subspecies have been recognised:[8]
The nominate subspecies, found at the Top End, follows Gould's original description.
The Arnhem Land population. The description for this subspecies was published by Oldfield Thomas after examination of new specimens that confirmed morphological distinctions in different localities. The type specimen, already held at the British Museum, was collected in 1902 by J. T. Tunney; he had killed this animal at Nellie Creek.[9]
A subspecies restricted to the Kimberley region.
A species of Petrogale, the rock wallabies, distinguished by its small size. The pelage is a grey colour, with reddish highlights at the fore-arm, legs and hind parts. The tail is also reddish grey, with a bushy end of coarser hair that begins two thirds along its length, the total length may be from 260 to 335 millimetres. The cheek is marked with a whitish stripe from the eye to the nostrils, a lighter tone that contrasts with the blackish parts of the snout. Another darker stripe is found below the eye and down the neck, the region beneath the fore-arm is also blackish. The head and body length combined in 310 to 365 mm, the smallest of the genus but for P. burbidgei. The measurement of the hindfoot is 95 to 105 mm, the ear from base to tip is 41 to 45 mm. The weight range is from 1.2 to 1.6 kilograms.[6]
The dentition of P. cocinna is unique amongst the marsupial species, with the supernumerary molars being continually replaced. These teeth emerge in a regular size and shape, with each row containing four to six molars and another that is yet to erupt. The early loss of the premolar appears to allow this regeneration to continue throughout their life.[7]
Nabarlek is often found with the similar P. brachyotis, whose coloration is more variable, and a young individual may be indistinguishable from this species in field observations.[10]
Nabarlek move quickly with a distinctive horizontal posture, the tail curled toward the middle of the back with raised hairs in the tufty end. The species has a timid disposition, although is somewhat gregarious in associations with others. Their feeding and other activities is usually nocturnal, and they may range beyond their refuge to forage.
The species will range several hundred metres from its secure position, foraging in the surrounding black soil terrain, this contrasts with the less venturous behaviour of the short-eared P. brachyotis.[7]
The discrete and cautious nature of narbarlek makes capture of specimens difficult, they are regarded as 'trap-shy' in attempts to survey their population.[10]
The diet includes a variety of plants, including grasses, ferns and sedges.[6] The plants consumed in Arnhem land during the wet season are the grass species of Eriachne and the sedges Cyperus cuspidatus and species of Fimbristylis, which occur in soils above the flood levels. The change in season has the species seek shelter during the day in sandstone formations and forage at local billabongs for a fern species Marsilea crenata.
The high percentage of silica in its diet, 15 to 25% in some foliage, was proposed to have favoured the continual regeneration of molars.[7] Attempts to locate the high silica fern in later surveys have not recorded Marsilea crenata at any sites, and the complex relationship between diet and dentition remains to be examined.[10]
The nabarlek is found in three distinct and geographically remote populations, one in Arnhem Land which includes Groote Eylandt, a larger island in the Gulf of Carpentaria, and another population between the Mary and Victoria Rivers at the Top End of the continent. The population in the northwest Kimberley region is confined to the coastal areas and on some of the islands in the Bonaparte Archipelago, these are Borda, Long, Hidden and Augustus Islands.[6]
The habitat is usually scrubby vegetation over sandstone formations, granitic outcrops, breakaways of laterite, boulder piles and rocky slopes.[6]
It is classified as Endangered by the IUCN.
Nabarleks (Petrogale concinna), are a tiny species of macropod found in northern Australia. They are a shy and nocturnal animal that resides in rocky hollows and forages in the surrounding area. Their diet is grasses, sedges, and ferns found in and around their scrub covered refuges. They are distinguished by a reddish tinge to the mostly grey fur and a distinct stripe at the cheek. They move with great speed and agility when observed, with a forward leaning posture and a bushy tail that arches over the back.
