Kangaroo Facts

Scientific Name: Macropus

Red Kangaroo
Red kangaroo, New South Wales, Australia.

 J and C Sohns/Getty Images Plus

Kangaroos are marsupials that are indigenous to the Australian continent. Their scientific name, Macropus, is derived from two Greek words meaning long foot (makros pous). Their most distinctive characteristics are their large hind legs, long feet, and large tail. Kangaroos are unique in that they are the only animals of their size that use hopping as their primary means of movement.

Fast Facts: Kangaroo

  • Scientific Name: Macropus
  • Common Names: Kangaroo, Roo
  • Order: Diprotodontia
  • Basic Animal Group: Mammals
  • Distinguishing Characteristics: Large hind legs, long feet, large tail and pouch (females)
  • Size: 3 - 7 feet in height
  • Weight: 50 - 200 pounds
  • Life Span: 8 - 23 years
  • Diet: Herbivore
  • Habitat: Forests, plains, savannas, and woodlands in Australia and Tasmania
  • Population: Approximately 40 - 50 million
  • Conservation Status: Least concern
  • Fun Fact: Like camels, kangaroos may go for periods of time without drinking water.

Description

Kangaroos are best known for their powerful hind legs, their large feet, and their long powerful tails. They use their legs and feet to hop around, which is their basic means of locomotion, and their tails for balance. Like other marsupials, females have a permanent pouch for raising their young. A kangaroo's pouch is technically called a marsupium and it performs a number of functions. The female kangaroo's breasts, which she uses to nurse her young, are inside her pouch. The pouch also functions similarly to an incubator to allow a joey (baby) to fully develop. Lastly, the pouch has a safety function in that it helps to protect the female's young from predators. 

Kangaroos are usually between 3 to 7 feet in height. They can weigh up to approximately 200 pounds. Other physical characteristics of kangaroos are their relatively small heads with their large, round ears. Due to their hopping ability, they can leap over long distances. Some males may leap to almost 30 feet in one leap.

Eastern Grey Kangaroo
Eastern Grey Kangaroo, Murramarang National park, New South Wales, Australia.  J and C Sohns/Getty Images Plus

Habitat and Distribution

Kangaroos live in Australia, Tasmania, and surrounding islands in a variety of habitats such as forests, woodlands, plains, and savannas. Depending on the species, kangaroos occupy different niches in the ecosystem.

Diet and Behavior

Kangaroos are herbivores and their diet consists mainly of a variety of plants such as grasses, shrubs and flowers. Some species may also eat fungi and moss. Kangaroos live in groups called "mobs," also known as troops or herds. These mobs are usually headed by the dominant male in the group. 

Similar to cows, kangaroos may regurgitate their food to chew it as cud and then swallow once more. This behavior is much rarer in kangaroos than in ruminant animals. Kangaroo stomachs differ from those of cows and similar animals; while both kangaroos and cows have chambered stomachs, the fermentation process in their respective stomachs is different. Unlike cows, the process in kangaroos doesn't produce as much methane, so kangaroos don't contribute as much to methane emissions globally as cows.

Kangaroos are usually active at night and in the early morning hours, but their overall activity pattern is varied. Their rest periods are restricted almost exclusively to a diurnal (during the day) pattern. Similar to camels, they may go for periods of time without drinking water due to their relative inactivity during the day when it is hotter. Since their diet consists of plants, their water needs can be largely satisfied by the water content present in the plants that they eat.

Reproduction and Offspring

Eastern Grey Kangaroo
Eastern Grey Kangaroo with Joey in Pouch.  Gary Lewis/Photolibrary/Getty Images Plus

Kangaroos have a varied breeding season. Reproduction takes place all year long, but the Australian summer months of December to February are the most common. Male kangaroos may flex their muscles to attract females and can fight for the right to breed with females. Females usually produce one baby kangaroo, called a joey.

After becoming impregnated, a kangaroo will have her baby after a gestation period of a little longer than a month (approximately 36 days). The baby joey weighs about .03 of an ounce and is less than one inch in length when born, about the size of a grape. After birth, the joey will use its forelimbs to travel through its mother's fur to her pouch, where it will remain for the first few months of its life. After five to nine months, depending on the species, the joey will typically leave the pouch for brief periods of time. After about nine to eleven months, the joey will leave its mother's pouch for good.

Females can enter heat after giving birth, so they may become pregnant while a joey is still nursing in her pouch. The developing baby will enter a dormant state that coincides with their older sibling leaving the mother's pouch. When the older sibling leaves the pouch, the mother's body will send hormonal signals to the developing baby so that it will resume its development. A similar process occurs if the mother is pregnant and the older joey dies in her pouch.

Conservation Status

Kangaroos are designated as least concern by the International Union for Conservation of Nature (IUCN). Their population is very abundant and by most estimates, there are more kangaroos in Australia than people. Estimates range from a population of 40 to 50 million kangaroos, which continues to increase.

Humans are the main threat to kangaroos since they are hunted for both their meat and their hides. Humans can also contribute to the loss of kangaroo habitat due to land clearing for development. Predator threats include dingos and foxes. Kangaroos use their teeth, claws, and strong hind legs as defense mechanisms against such predators.

Species

There are four major species of kangaroos. The red kangaroo (Macropus rufus) is the largest. Males of the species have red/brown fur. Other species include the eastern grey kangaroo (Macropus giganteus), the western grey kangaroo (Macropus fuliginosus), and the antilopine kangaroo (Macropus antilopinus). The eastern grey kangaroo is the second largest species and is known as the great grey species, while the western grey kangaroo is also known as the black-faced kangaroo due to its distinctive facial coloring. The antilopine's name means antelope-like and they are found in northern Australia. Some scientists consider there to be six species of kangaroo, including two species of wallaroo (Macropus robustus and Macropus bernardus). Wallaroos are considered to be closely related to both wallabies and kangaroos.

herd of kangaroos
Herd of kangaroos at twilight (Coombabah Lake, QLD, Australia).  

Kangaroos and Humans

Humans and kangaroos have a long and varied interaction pattern with one another. Humans have long used kangaroos for food, clothing, and some types of shelter. Due to their increasing numbers, kangaroos can be viewed as pests, particularly by farmers when kangaroos compete for grazing land. Kangaroos are often present in grasslands and areas that are typical farmland so resource competition may take place. Kangaroos are not typically aggressive when grazing. The situation of farmers seeing kangaroos as pests is similar to how many in the United States may see deer as pests.

Sources

  • Britannica, The Editors of Encyclopaedia. "Kangaroo." Encyclopædia Britannica, Encyclopædia Britannica, Inc., 11 Oct. 2018, www.britannica.com/animal/kangaroo.
  • “Kangaroo Facts!” National Geographic Kids, 23 Feb. 2017, www.natgeokids.com/uk/discover/animals/general-animals/kangaroo-facts/.
  • “Kangaroo Mob.” PBS, Public Broadcasting Service, 21 Oct. 2014, www.pbs.org/wnet/nature/kangaroo-mob-kangaroo-fact-sheet/7444/.
  • “Kangaroo Reproduction.” Kangaroo Facts and Information, www.kangarooworlds.com/kangaroo-reproduction/.