The wallaby is a close relative of a kangaroo, and one can classify it by saying it is any animal that looks like a small kangaroo. Both are members of the same family, Macropodidae. Animals larger than wallabies, but smaller than kangaroos, are called wallaroos.
There are just over 30 separate species of the wallaby, residing primarily in Australia. Some species can be found in Tasmania. The animal was introduced to New Zealand and now there is a small but resilient colony there as well. There are also a about five species in New Guinea, and most unusually, Hawaii has a small population of the Brush-tailed Rock Wallaby, established when a pair escaped from a private zoo.
Like the kangaroo, the wallaby is a marsupial. Marsupials raise their very tiny newborns in pouches for several months to over year. The Tamar wallaby, for example, has an average gestation period of less than a month. The then tiny 0.1 of an ounce (0.28 g) newborn will spend about five months in the pouch before being considered an adolescent.
Gestation period and time in the pouch varies between different species. Since wallabies come in so many variations, it is difficult to discuss average size. One of the largest is the Bennet’s wallaby. These can grow to be about 40 inches (1.01 m) tall, and may weigh approximately 35 pounds (15.87 kg) when mature. The Tamar or Scrub wallaby is the smallest of the species. Mature adults may be up to 18 inches (0.45 m) tall and weigh approximately 13.5 pounds (6.12 kg). For further size comparison, one might note that the Bennet’s wallaby is about the third the size of the largest kangaroos.
Life expectancy also varies, and often depends upon the size of the animals. The Tamar may live about 5 years, the Bennet a few years longer. Behavior also differs between species. Most are exclusively herbivorous, but some species are diurnal (sleeping at night) and others nocturnal (sleeping during the day). What kind of wallaby one might see in its native locations depends on what time of day the it is seen.
Like the kangaroo, the wallaby has large flat feet that make jumping quite easy. They also have exceptionally long tails, which help to provide balance for jumping. The tail length is usually not included in height measurements, but as a general rule tends to measure approximately 1/3 of the body height. Most of the species are gray, brown, or gray or brown with cream. Some have auburn tints in their fur, like the Red-Necked wallaby. The back is gray, the neck red, and the underbelly cream.
Wallabies compete well with kangaroos because of their smaller size. They tend to enjoy eating grasses, and the leaves on shorter bushes. The kangaroo also is a grass grazer but can access bushes higher up. The wallaby is slightly more at risk for predation by dingoes because of its size. This is particularly the case with the smaller members of the species. Like kangaroos, interactions with humans can be problematic, and both animals may eat crops. Additionally, cars often accidentally hit and kill wallabies.
Most wallaby species are not endangered and have adapted well to increasing human encroachment on their habitat. A few species, however, are considered endangered. These include the Brush-tailed Rock wallaby, and the Nail-tailed wallaby. Conservation efforts are underway to save and restore the populations of these and other endangered species.