Wallaby

Wallaby vs. kangaroo

There is no formal biological distinction between kangaroo and wallaby — both belong to the family Macropodidae, sharing the marsupial pouch, hopping locomotion, and grazing/browsing diet. The naming convention is loose:

• Larger species are typically called “kangaroo” (red kangaroo, eastern grey kangaroo).
• Smaller species are typically called “wallaby” (red-necked wallaby, swamp wallaby).
• Mid-sized species are called “wallaroo” — neither one nor the other.
• Tree-dwelling species are called “tree-kangaroo” regardless of size.

The terminology is a colloquial English convention rather than a taxonomic one.

Many species

Wallabies include about 30 species:

• Red-necked wallaby (Notamacropus rufogriseus) — most common in southeastern Australia.
• Swamp wallaby (Wallabia bicolor) — coastal eastern Australia.
• Rock wallabies — adapted for cliffs and rocky terrain (yellow-footed rock wallaby).
• Pademelons — small forest wallabies of New Guinea and Australia.
• Quokka — covered separately; technically a wallaby.
• Hare-wallabies — small open-country species, several extinct.

Introduced populations

Wallabies have established feral populations outside Australia:

• New Zealand — five wallaby species introduced 1870s as game; now invasive pests.
• United Kingdom — small populations in the Peak District and Isle of Man, descended from escaped pets and zoo animals.
• Hawaii — small population on Oahu, possibly extinct.
• Continental Europe — occasional small populations from zoo escapes.

These introduced populations cause ecological problems — wallabies graze native plants and don’t fit into the ecological communities they’ve invaded.

A pouch with rules

Like all marsupials, wallabies give birth to extremely premature young — about the size of a jelly bean. The young crawl unaided into the pouch, latch onto a teat, and complete their development there over months.

Female wallabies can host multiple young at different developmental stages simultaneously: a “joey” out of the pouch but still nursing, plus a younger one in the pouch, plus a fertilized egg paused in development waiting for the pouch to free up.