Wallaby

Category: Wildlife

Basically, wallabies are small to medium sized kangaroos that are heavier bodied than the standard kangaroo. There is no real scientific definition of the name to help understand the classification. While not quite as mysterious to non-native Australians as koalas or platypus, wallabies nonetheless fascinate people. They are no longer restricted to that one area of the world, however. Colonies of the descendants of escaped zoo wallabies can be found in Hawaii, England, Ireland, and mainland Europe.

Wallaby

Wallaby

Scientific & Common Names

Kingdom - Animalia

Phylum - Chordata

Class - Mammalia

Infraclass - Marsupialia

Order - Diprotodontia

Family - Macropodidae

Genus – Wallabia; Macropu; Petrogale; Onychogale; Lagorchestes; Thylogale; Dorcopsulus

Common Names – Wallaby, Brush Wallaby(11 species), Rock Wallaby(6 species), Scrub Wallaby(3 species), Hare Wallaby(2 species), Forest Wallaby(3 species), Dwarf Wallaby(1 species)

Characteristics

They range in size from the tiny dwarf at only 18 inches, to the larger species that can reach over three feet to unusual lengths of even six feet. They can live in a variety of environments and are well adapted to each. Rock wallabies have feet adapted to grip rocks in their rugged terrain while the red necked wallaby is almost indistinguishable from a kangaroo.

Breeding

As marsupials, wallabies give birth to young that are extremely underdeveloped and must remain in the mother's pouch for an extended period of time. There is no placenta formed, so only the yolk nurtures the embryo. About the size of a lima bean, the young joey - or joeys, twins are possible - must make its way to the pouch, where it will attach itself to a nipple until it gains the ability to detach and move more. The mother will often breed immediately after giving birth but the embryo will not develop until the current joey is gone, either from maturing or being lost. This is called embyonic diapause and is common with kangaroos.

Behavior

They are herbivores but, like kangaroos, they are extremely adept at defending themselves, using their powerful hind legs and even punching with their forearms.

History

Although the ancestor of modern kangaroos and wallabies most likely walked upright and did not hop, almost all modern kangaroos lack the ability to walk on two legs. Around 55 million years ago, they split from their ancestors and began evolving as a arboreal species. With the loss of the abundant rainforests around 20 million years ago, the modern day kangaroos began to live in open areas and new species formed. With the return later of large rainforests, tree kangaroos began to return, leading to the wide variety of species seen today.

Present Status

The Rufous Hare Wallaby (L agorchestes hirsutus ) is vulnerable. Parma Wallaby (Macropus parma) is listed as Near Threatened, as is the Brush Tailed Rock Wallaby (Petrogale penicillata) and the Yellow footed Rock Wallaby (Petrogale xanthopus). The Banded Hare Wallaby (Lagostrophus fasciatus) is endangered, as is the Bridled Nailtail Wallaby (Onychogalea fraenata), and the Proserpine Rock Wallaby (Petrogale persephone). The Eastern Hare wallaby (Lagorchestes leporides) is extinct, with the last known specimen collected in 1890. The Crescent Nailtail Wallaby (Onychogalea lunata) is also extinct, possibly since the 1950's. In all cases, the major threats were from introduced species that preyed on the wallabies or altered their environments.

References

  1. International Union for Conservation of Nature and Natural Resources (IUCN)
  2. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)
  3. National Geographic June 2010
  4. Kangaroo Creek Farm
  5. Kangaroos may be hoppers, but they evolved from walkers By James Maynard, Tech Times