Swamp Wallaby

Researchers reported that the swamp wallaby is the only mammal that is pregnant and lactating throughout its adult life.

• About the Animal:

Swamp wallaby is a species of marsupial and the only living member of the Wallabia genus. It is found in the woodlands and forests of Australia. They are solitary (except while feeding) and mainly feed on food plants. They have 2 uteri and 2 ovaries, like kangaroos.

• Embryonic Diapause:

Embryonic diapause is a strategy used by certain animals to pause reproduction till the arrival of favourable conditions. In case of swamp wallabies, they use this to ensure that the pouch is free when a new one is born. This is because they regularly have a foetus in the uterus, a joey in the pouch and a semi-dependent young one at foot- all at the same time.

• Difference from Kangaroos:

Kangaroos have many similarities with the swamp wallabies when it comes to reproduction. The difference is that in kangaroos, the next embryo is conceived only a day or two after the previous birth. In case of swamp wallabies, the next embryo is conceived even before the previous one is born.

• Difference from the European Brown Hare:

European brown hare is the only other mammal that conceives before the previous offspring is born. The difference is that the new embryo is conceived in the same uterus in case of the hare, while in the wallabies, it’s conceived in the second uterus. The other difference is that the hare has distinct breeding seasons while the wallabies are pregnant and lactating throughout the year.