The swamp wallaby has got everyone crying “panther”

By Bec Crew | March 19, 2018

Let’s face it. There’s nothing more Australian than the swamp wallaby. Or as Australians in the east like to call it, the black stinker.

Contributor

Bec Crew

Becky Crew is a Sydney-based science communicator with a love for weird and wonderful animals. From strange behaviours and special adaptations to newly discovered species and the researchers who find them, her topics celebrate how alien yet relatable so many of the creatures that live amongst us can be.

LIKE THE IBIS of the marsupial world, the swamp wallaby has a reputation for a bad smell, but there’s more to this weird little macropod than meets the eye.

Long thought to be the only living member of the Wallabia genus, the swamp wallaby (Wallabia bicolor) is different from all the other wallabies because of its unique teeth and chromosome number – while other wallabies have 16 chromosomes, swamp wallaby males have ended up with 11 chromosomes, and the females have 10.

Their reproductive behaviour is also strange, and makes regular motherhood look, well, not so bad by comparison.

Unlike other marsupials, the female swamp wallaby’s gestation period is longer than its oestrous cycle, which means they can start to mate when they’re already pregnant, ensuring overlapping pregnancies for constant babies.

And to make matters worse for these prolific mums, swamp wallabies can breed all year round. 

Panther sighting

Swamp wallabies also have a unusual gait, which causes them to carry their head low and their tail straight.

This behaviour, combined with the species’ dark, sometimes black, coat, has resulted in a whole lot of “panther sightings” along the east coast of Australia.

Because I guess if you saw this skulking through the bush from behind, you’d probably at least do a double-take:

swamp wallaby

(Image Credit: Benjamint444/Wikimedia)

In fact, we might even be able to blame some unwitting swamp wallabies for the indelible Blue Mountains panther myth.

Genetic mystery

While swamp wallabies (and feral dogs and cats) are likely keeping the panther mystery alive, the species has its own unfinished story to tell.

Late last year, evolutionary biologists from the Queensland University of Technology (QUT) discovered that its genes are actually similar enough to place it into the genus

Macropus, which includes the grey and red kangaroos, wallaroos, and the smaller woodland wallabies of Australia and New Guinea.

They discovered this by looking at the aptly named ‘jumping genes’ (or retrotransposons) of the swamp wallaby – so-called because they literally jump across the genome.

The study identified six different retrotransposons that were uniquely shared by the swamp wallaby and the woodland wallabies, which indicated a shared ancestry between the two.

While the researchers say this is evidence enough to place the swamp wallaby into the Macropus genus instead of the Wallabia genus,this has not yet been made official. But it might be only a matter of time before this species gets a major name change

And finally, let’s not forget perhaps the most famous swamp wallaby of them all – Syd, the tough little guy who somehow made it onto the Sydney Harbour Bridge earlier this year, just two weeks before ‘Christine’ the swamp wallaby was found swimming in Sydney Harbour.

New favourite animal right here.