Antilopine Wallaroo

## About

A male antilopine wallaroo.

The antilopine wallaroo ***(Osphranter antilopinus)***, also widely known as the antilopine kangaroo is a seldom-studied wallaroo species native to the northern tropics of Australia and one of three known wallaroo species. The antilopine wallaroo is named for its superficial resemblance to African antelopes, specifically in relation to its similar coat. The antilopine wallaroo is one of few sexually dimorphic marsupials and individuals vary in size and weight depending on sex. Colouration varies between sexes and is grey in females and a mixture of grey, tan and reddish orange in males. In males the reddish orange parts being predominantly on the back and shoulders, while the back is more brownish tan. Females also have white-tipped ears and both sexes have black-tipped hands and feet. They are often confused with the closely related red kangaroo ***(Osphranter rufous)*** because of their similar physical appearance. Like all macropods, antilopine wallaroos are bipedal and locomote via the use of their powerful legs, which allow them to quickly hop via the use of specialised tight muscles which accommodate the stretching of tendons during hopping. During a taxonomic reassessment in 2015 in *Taxonomy of Australian Mammals* by Stephen Jackson and Colin Groves, the antilopine and red kangaroos were reclassed as being part of the genus ***(Osphranter)***, a former subgenus of ***(Macropus)***. Antilopine wallaroos can grow up to 1.2-1.9m (3.9-6.2ft) with males being considerably larger. Females weigh between 20-30kg (22-66lbs) while males can reach up to 40-70kg (88-154lbs). The antilopine wallaroo is one of the largest marsupial species.

## Diet

Antilopine wallaroos are herbivorous and prefer grazing short grasses like tussock grass. They also seek out areas where fires have burnt tall grasses, leaving shoots.

## Conservation Status

The antilopine wallaroo has been described as abundant through its range and large in population however, the species has faced declines due mostly to bushfires. Because of little threats, the antilopine wallaroo is listed as least concern by the IUCN.

## Range and Population

The antilopine wallaroo occurs throughout northern Australia, inhabiting tropical woodlands, monsoonal/coastal wetlands, savannas and coastal areas. Two main subpopulations exist, one in the Cape York Peninsula in Queensland and the other in the Gulf of Carpentaria in the Northern Territory and the Kimberly region of northern Western Australia. The subpopulations are separated by 500km (310mi) of desolate grassland at the base of the Gulf of Carpentaria. Eastern populations prefer to inhabit lowland valleys, slopes and hills while northern populations show a preference for areas with permanent water sources, likely as a way to compensate seasonal fires. Populations which occur in wooded areas have been known to seek shelter during rain and monsoons. The population of the species has been denoted as widespread and individuals are abundant however, the population is still in likely decline, due to previously mentioned factors.

## Behaviour

The antilopine wallaroo is a social species which occurs in groups known as mobs, with both young males and females of up to 30 individuals. Breeding occurs year-round and males will attract a potential mate by displaying their erected member and sniffing the female's cloacal region. Once a baby is conceived, the gestation will last 35 days with the neonate climbing into the pouch, before developing for a further 20 weeks. Finally, after 6 months the joey will emerge for the first time and following the proceeding 37 weeks, she will not allow the joey to re-enter the pouch. The joey is gradually weaned up until 15 months from birth, after which the joey will maintain a close bond with their mother, allogrooming. Only one offspring is produced per breeding season. Males will be segregated after joeys reach their mother's pouches, creating hierarchal bachelor groups without any females. Older males are solitary, as infighting between sexually mature males is common. Prior to fighting, males will make an audible alarm call, before thumping their feet and then shaking their heads in preparation. Males are unsurprisingly very territorial and can form home ranges of up to 100ha (247ac), while females only make ranges of 20ha (49ac). Females will then form larger mobs of just mothers and their young. Grazing and travelling among mobs and as individuals is common, but a wallaroo will always return to an exact area, or what is called their 'camp'.

### Relationship with Humans

Antilopine wallaroos were and are continually hunted by the Aboriginal people of northern Australia and the species remains an important cultural symbol. Among agriculturalists, the antilopine wallaroo is seen as a competitor to livestock for food.

## In Captivity

Antilopine wallaroos are not as favoured as other kangaroos in captivity, as they are more enigmatic and overall less popular among the public.

## Sources

* IUCN Red List or Threatened Species - https://www.iucnredlist.org/species/40561/21953729
* Antilopine Wallaroo | Wikipedia - https://en.wikipedia.org/wiki/Antilopine\_wallaroo
* Antilopine Wallaroo | Animal Diversity Web, University of Michigan Museum of Zoology - https://animaldiversity.org/accounts/Macropus\_antilopinus/
* Sneaky Hoppers in the Australian Tropics | Australian Museum - https://australian.museum/blog-archive/science/amri-sneaky-hoppers/