The common wallaroo (''Osphranter robustus''), also known as the euro, hill wallaroo, or simply wallaroo, is a species of macropod. The word ''euro'' is particularly applied to one subspecies (''O. r. erubescens'').WE Poole and JC Merchant (1987): ''Reproduction in Captive Wallaroos - the Eastern Wallaroo, Macropus-Robustus-Robustus, the Euro, Macropus-Robustus-Erubescens and the Antilopine Wallaroo, Macropus-Antilopinus.'' Australian Wildlife Research 14(3) 225 - 242
online link
/ref> The eastern wallaroo is mostly

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

and solitary, and is one of the more common macropods. It makes a loud hissing noise and some of the other subspecies are

sexually dimorphic Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

, like most wallaroos.

Subspecies

There are four subspecies: *the eastern wallaroo (''O. r. robustus'') – found in eastern Australia; males of this subspecies have dark grey fur, almost resembling the

black wallaroo The black wallaroo (''Osphranter bernardus''), also known as Woodward's wallaroo, is a species of macropod restricted to a small, mountainous area in Arnhem Land, Northern Territory, Australia, between South Alligator River and Nabarlek. It cl ...

(''Osphranter bernardus''). Females are lighter, being almost sandy in colour. *the euro or western wallaroo (''O. r. erubescens'') – found covering most of the species' remaining range to the west; this subspecies is variable, but mostly brownish, in colour. *the Barrow Island wallaroo (''O. r. isabellinus'') – this subspecies is restricted to Barrow Island in

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

and is comparatively small. It is uniformly reddish-brown. *the Kimberley wallaroo (''O. r. woodwardi'') – this subspecies is found in the Kimberley region of Western Australia and in a band roaming through the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

. It is the palest of the four subspecies and is a dull brown-grey colour. Kunwinjku of western Arnhem Land call this subspecies ''ngabudj''. They also have separate names for male and female, ''galkibard'' and ''wallaar'', respectively. A large male is called ''ganduki''. This animal manages well in areas without permanent water and on a diet of nutrient-poor grasses, but it does need shelter. The eastern wallaroo (''O. r. robustus'')—which is dark grey in colour—occupies the eastern slopes of the

Great Dividing Range The Great Dividing Range, also known as the East Australian Cordillera or the Eastern Highlands, is a cordillera system in eastern Australia consisting of an expansive collection of mountain ranges, plateaus and rolling hills. It runs roughl ...

, and the euro (''O. r. erubescens'')—which is mostly brownish in colour—occupies the land westward.

Reproduction

Wallaroo females can give birth at any time during the year. Through a process called

embryonic diapause Embryonic diapause (delayed implantation in mammals) is a reproductive strategy used by a number of animal species across different biological classes. In more than 130 types of mammals where this takes place, the process occurs at the blastocys ...

they are able to get pregnant any time after giving birth, but the embryo does not start to develop until the previous joey is able to leave the pouch of the mother. Wallaroos are also polygynous, which means that the males can have multiple female partners. Male wallaroos will engage in non-deadly physical combat over mating access to females. The gestation period lasts around 30 to 38 days, after which the young joey travels into the mother's pouch where it suckles and develops. The young joeys start to leave the pouch at around six months and by nine months they no longer spend most of their time in the pouch. Male wallaroos are fully developed at around 18 to 20 months; females are fully developed at around 14 to 24 months. The relationship with the joey and their parents changes as the joey grows and gets older. During the time in which the joey is in the pouch, the father stays around to protect the joey and mother from predators, but once this protection is no longer needed the relationship weakens between the two. After the joey no longer needs its mother for food, it still maintains a close relationship with her.

Status

The eastern wallaroo as a subspecies is not considered to be threatened, but the Barrow Island subspecies (''O. r. isabellinus'') is classified as vulnerable.

Taxonomy

In 2019, a reassessment of macropod taxonomy determined that the species should be moved from the genus '' Macropus'' to the genus ''

Osphranter ''Osphranter'' is a genus of large marsupials in the family Macropodidae, commonly known as kangaroos and wallaroos (among other species). It contains the largest extant marsupial, the red kangaroo (''O. rufus''). In 2019, a reassessment of mac ...

''. This change was accepted by the Australian Faunal Directory in 2020.

References

External links

Animal Diversity WebPhotos at ARKive.
{{Taxonbar, from=Q691473 Macropods Mammals of Western Australia Mammals of South Australia Mammals of the Northern Territory Mammals of New South Wales Mammals of Queensland Mammals of Victoria (state) Marsupials of Australia Mammals described in 1841 Taxa named by John Gould