I Smell a (Musky) Rat...

Skyrail Nature Diary: July 2007

Do you smell a rat? If you’re in the rainforest during July and you detect a musky odour, there may be a Musky Rat-kangaroo (Hypsiprymnodon moschatus) nearby.

Deriving its common name from the odour it emits during the mating season, the Musky Rat-kangaroo is thought to be the evolutionary link between primitive possum species and the modern kangaroo family (macropods).

Measuring 25 centimetres in length and dating back over 15 million years, it is Australia’s smallest and most primitive kangaroo

The Musky Rat-kangaroo’s closest living relatives are kangaroos and wallabies; however this tiny kangaroo displays several unique physical characteristics which set it apart from its more famous cousins.

Firstly, it is the only modern macropod to have an opposable digit on the hind foot, allowing it to climb effectively in the rainforest. It is also the only macropod to have retained its ancient, hairless, scaly tail, which can reach 15 centimetres in length.

This is also the only kangaroo to have more than one young in its pouch at a time. In fact, female Musky Rat-kangaroos can be found nursing two or three young at once during the breeding season, which runs from February to July.

Unlike most other mammals in Australia’s Tropical Rainforests, the Musky Rat-kangaroo is diurnal, meaning it is more commonly seen during the day than its nocturnal neighbours. However, don’t expect to spot these cute critters bounding across the forest floor like a mini-kangaroo; the Musky Rat-kangaroo runs on all fours, much like a rabbit.

Preferring thick rainforest near water courses, the Musky Rat-kangaroo spends its days scouring the rainforest floor for insects, worms, and rainforest fruit, assisting with the spread of rainforest seeds in the process.

The Musky Rat-kangaroo’s dining habits were the source of much interest to the scientific community in 2002, when it became the first animal in Australia’s Tropical Rainforests to be recorded ‘scatterhoarding’ food by zoologist Andrew Dennis. This means that instead of just searching for fruit and eating on the go, Musky Rat-kangaroos plan ahead; they find a surplus of food when it is plentiful, and bury it for times of food shortages.

This strategy must be effective: while the Musky Rat-kangaroo is only found in Australia’s Tropical Rainforests, its populations are thriving and it is not listed as a threatened species.

The Musky Rat-kangaroo is one of the 13 endemic mammal species found in Australia’s Tropical Rainforests. Despite accounting for just 0.01% of Australia’s landmass, these rainforests are home to 36% of Australia’s mammal species.