Common Water Rat vs koala

Hydromys chrysogaster compared with Phascolarctos cinereus

Key Differences

• Common Water Rat is Least Concern while koala is Vulnerable.

Taxonomic Classification

Rank	Common Water Rat	koala
Kingdom same	Animalia (动物界)	Animalia (动物界)
Phylum same	Chordata (脊索动物门)	Chordata (脊索动物门)
Class same	Mammalia (哺乳動物)	Mammalia (哺乳動物)
Order	Rodentia (啮齿目)	Diprotodontia (雙門齒目)
Family	Muridae (Mice & Rats)	Phascolarctidae (Koalas)
Genus	Hydromys	Phascolarctos (Koalas)
Species	Hydromys chrysogaster	Phascolarctos cinereus

Evolutionary Relationship

Common Water Rat and koala share a common ancestor at the Class level: Mammalia. (哺乳動物)

Conservation Status

Common Water Rat

LC — Least Concern

koala

VU — Vulnerable

Population: ~100.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Common Water Rat	koala
Diet	—	Herbivore
Average Lifespan	—	15 years
Average Length	—	75 cm
Average Weight	—	10.0 kg

Habitat & Geographic Range

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

koala

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

Found in Australia. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Water Rat

<em>Hydromys chrysogaster</em>, commonly known as the common water rat or rakali, is a semi-aquatic rodent in the family Muridae, native to Australia and New Guinea. It is classified as Least Concern by the IUCN, reflecting its relatively stable population across a broad range of freshwater and estuarine habitats on the Australian continent and associated islands. The species typically inhabits the banks of rivers, lakes, wetlands, and estuaries, where it constructs burrows in streambanks. It is highly adapted for an aquatic lifestyle, with partially webbed hind feet, a flattened head, and a dense waterproof coat. <em>Hydromys chrysogaster</em> is a carnivore, typically feeding on fish, crustaceans, mussels, frogs, and aquatic invertebrates, which it often carries to elevated feeding platforms to consume. The species is nocturnal and crepuscular, most active during early morning and evening hours near the water's edge. Biological traits including average lifespan, body length, and weight remain poorly documented in standardized databases, though adults are generally robust for a rodent, reportedly reaching body lengths of 20–35 cm excluding the tail. Geographic range details for this particular record remain incompletely documented in available data sources. Ecologically, the common water rat is an important apex predator in small-scale freshwater food webs and serves as an indicator species for wetland health in Australian riparian systems.

koala

澳大利亚东部和东南部的标志性有袋类动物，体重最大可达15千克，为了节省低热量桉树叶食物所提供的能量，每天最多睡眠22小时。高度特化，能够处理会致大多数其他哺乳动物死亡的有毒桉树成分，拥有专门适应解毒功能的肠道微生物群。因衣原体病、栖息地开发和气候变化导致种群锐减，2022年被列为濒危物种。