Hippopotamuses are not native to Australia, and there are no established wild populations of either the Common or Pygmy Hippopotamus. Australia’s unique natural history means these large, semi-aquatic mammals were never part of the country’s fauna in a natural setting.
The Definitive Answer
Australia’s unique biological landscape resulted from its long isolation following the break-up of the Gondwana supercontinent. This continental drift allowed its marsupials and monotremes to evolve separately from the placental mammals of Africa and other landmasses. The absence of hippos, along with other large African mammals like elephants and rhinos, is a direct consequence of this evolutionary history.
There has never been a successful introduction of hippos into the Australian wild. The idea was once floated in the early 20th century to introduce African species to the tropical north, but this project never gained traction. A single Pygmy Hippopotamus once escaped from a private park in the Northern Territory and survived for approximately five years before its eventual capture. This incident confirms that a self-sustaining wild population has never taken root.
Where Hippos Naturally Thrive
Hippopotamuses are indigenous exclusively to the waterways and grasslands of Sub-Saharan Africa. The Common Hippopotamus (Hippopotamus amphibius) ranges across East and Southern Africa, inhabiting rivers, lakes, and wetlands. These massive mammals spend the majority of their day submerged in water to keep their skin cool and hydrated.
The species emerges from the water at dusk to graze on short grasses, consuming significant amounts of vegetation nightly. A second, much smaller species, the Pygmy Hippopotamus (Choeropsis liberiensis), is limited to the dense forests and swamps of West Africa, primarily in Liberia. This smaller cousin is a shy, solitary forest dweller, contrasting with the larger, more social and territorial common hippo.
Australian Waterway Occupants
Australia’s large semi-aquatic niche is occupied by two species of crocodiles, the dominant large reptiles in the northern waterways. The Saltwater Crocodile (Crocodylus porosus), or “Saltie,” is the world’s largest living reptile and an apex predator. These powerful reptiles inhabit coastal rivers, estuaries, and freshwater areas across the tropical north.
Saltwater Crocodile males commonly reach lengths of 4 to 5 meters, with some individuals exceeding 6 meters. Their robust body and broad snout are adapted for tackling large terrestrial prey, distinguishing them ecologically from the herbivorous hippo. The second species, the Freshwater Crocodile (Crocodylus johnstoni), is smaller, typically growing to 2 to 3 meters, and possesses a narrower snout suitable for catching fish and smaller invertebrates.
The presence of crocodiles means that, unlike hippo-dominated African rivers where the hippo is the primary consumer, Australian waterways are ruled by pure carnivores. Australia is home to other unique semi-aquatic mammals, such as the egg-laying platypus, which forages for invertebrates in freshwater rivers in the east. In the tropical coastal waters of the north, the dugong, a large marine herbivore, fills an ecological role analogous to the hippo’s grazing.