Kangaroos are giant-sized marsupials that can only be found in Australia. They are easily identified by their strong back legs, long pointed ears, large feet, short fur, and muscular tails.
Marsupials are a type of mammal, and their females have pouches where their mammary glands are located, and where their young stay until they are old enough to be independent.
Kangaroos are a member of the Macropodidae family, which includes wallabies, tree-kangaroos, wallaroos, pademelons, and quokkas.
When people talk about kangaroos, the four dominant species that come to mind are in the genus Macropus: the red kangaroo, the antilopine kangaroo, the eastern gray kangaroo, and the western gray kangaroo.
These species are sometimes called the “great kangaroos” because they are much bigger than other species of kangaroos.
However, there are a dozen species of tree-kangaroos in the Dendrolagus genus, per the Integrated Taxonomic Information System.
According to National Geographic, the most giant-sized kangaroo, and also the most significant existing marsupial, is the red kangaroo.
The red kangaroo measures 3.25 to 5.25 feet (1 to 1.6 meters) in length from its head to its rump.
The tail of the red kangaroo adds 35.5 to 43.5 inches ( between 90 to 110 centimeters) to the length, and the entire bodyweight of the kangaroo is about 200 lbs. (90 kilograms).
The smallest sized kangaroo is the musky rat-kangaroo. The musky rat-kangaroo is only about 6 to 8 inches (15.24 to 20.32 cm) in length and weighs not more than 12 ounces (340 grams).
The ratlike tail of this kangaroo adds an additional 5 to 6 inches (12.7 to 15.24 cm) to its body length.
Almost every kangaroo live in Australia, though individual species have a specific place it prefers to call home.
For instance, the musky rat-kangaroo loves to take shelter down in tiny nests on the floor of the northeastern Queensland rainforests. Gray kangaroos prefer to live in the forests of Tasmania and Australia, on the other hand.
As for the antilopine kangaroo, you can find it in the monsoonal eucalyptus woodlands northern Australia. The Tree-kangaroos are another exotic species that live in the upper branches of trees on the island of New Guinea, and the rainforests of Queensland.
Kangaroos are the only big animals that hop as a significant means of locomotion. They have springy hind legs and feet that are a lot stronger and more substantial than their or forelimbs.
According to information by the San Diego Zoo, kangaroos are capable of covering as much as 15 feet (7 m) in one hop, and they can hop as fast as 30 mph (48 kph).
Usually, we consider 20 mph (32 kph) as their cruising speed. Kangaroos use a slower movement when eating, walking, and for that, and kangaroos make use of their muscular tail as a fifth leg, bouncing off the ground as they go around.
Kangaroos are very social animals and live in groups known as a mob, a troop, or a herd. Kangaroos in a mob are friendly to each other, groom each other, and protect themselves from danger.
If one from a mob of kangaroos suspects there is danger in the area, the kangaroo will stomp its foot on the ground as a way to alert others. When it comes to throwing punches, a kangaroo will put up good boxing and kicking match once there is an opponent.
Kangaroos are not meat eaters; they are herbivores. They feed on ferns, grasses, moss, flowers, leaves, and sometimes insects. Like cows and other ruminant animals, kangaroos regurgitate whatever they eat and chew it again before it is ready to be fully digested.
Probably one of the most popular facts about kangaroos is that they have pouches in which they carry their babies. A female kangaroo’s pregnancy lasts for 21 to 38 days, which is about five weeks, and she can birth as many as four offspring at a time, though it is unusual for this to happen.
The baby kangaroo, just like the young of other marsupials (like koalas and wallabies), is called a joey, can be as small as tiny as a grain of rice, or as big as a bumblebee, at 0.2 to 0.9 inches ( approximately 5 to 25 millimeters), per details from the San Diego Zoo.
When a joey is born, it carefully makes its way into the mum’s comfy pouch, where it gestates for an additional 120 to 450 days.
Inside the mother kangaroo’s pouch, the joey is kept safe and feeds by nursing from its nipples of the mammary glands inside the pouch. Joeys don’t come out of the pouch when it needs to urinate and defecate.
The lining of the mother kangaroos pouch soaks up some of Joey’s mess, but at times, the mother kangaroo will need to clean the pouch out, which she does by sticking her long snout into her pouch and removing the contents with her tongue.
A joey in its mother’s pouch will remain latched to a nipple while the mother kangaroo does her cleaning, but any older joey will be kicked out of the pouch temporarily.
Another fantastic fact about mother kangaroos is that they can nurture two joeys at varying developmental stages simultaneously using milk that contains different nutritional content; this is something other animals can’t do.
Joeys grow quite fast, and from 14 to 20 months for females kangaroos or 2 to 4 years for male kangaroos, they will be fully grown and independent.
The taxonomy of kangaroos, rat- kangaroos, and tree-kangaroos, according to ITIS, is:
- Kingdom: Animalia
- Subkingdom: Bilateria
- Infrakingdom: Deuterostomia
- Phylum: Chordata
- Subphylum: Vertebrata
- Infraphylum: Gnathostomata
- Superclass: Tetrapoda
- Class: Mammalia
- Subclass: Theria
- Infraclass: Metatheria
- Order: Diprotodontia
- Suborder: Macropodiformes
- Family: Macropodidae
- Subfamily: Macropodinae
- Genus & species: Macropus giganteus (eastern gray kangaroo; two subspecies), Macropus fuliginosus (the western gray kangaroo; three subspecies), Macropus rufus (red kangaroo), and Macropus antilopinus (antilopine kangaroo)
Taxonomy of Tree-kangaroos
- Family: Macropodidae
- Subfamily: Macropodinae
- Genus: Dendrolagus
- Species: 12 species including Dendrolagus goodfellow (Goodfellow’s tree-kangaroo), Dendrolagus matschiei (Huon tree-kangaroo), Dendrolagus bennettianus (Bennett’s tree-kangaroo), and Dendrolagus spadix (Lowlands tree-kangaroo).
- Family: Potoridae
- Genera & species: Aepyprymnus rufescens (Rufous bettong or Rufous rat-kangaroo), Bettongia (four species of bettongs, or short-nosed rat-kangaroos), Caloprymnus campestris (desert rat-kangaroo)
- Family: Hypsiprymnodontidae
- Genus & species: Hypsiprymnodon moschatus
There is a wealth of fossil record for ancient relatives, and kangaroo ancestors. There is evidence to prove that giant kangaroos roamed the earth through the Pleistocene (2.6 million to 11,700 years ago) and the Pliocene (5.3 million to 2.6 million years ago).
Also, around 20 million years before now, tiny ancestors of what we know are modern kangaroos and a related group of kangaroos that had fangs inhabited deep forests in northwestern Queensland, Australia, a location that is now arid outback.
In a February 2016 study, scientists described a new genus of kangaroo, Cookeroo, and two new species: Cookeroo hortusensis, which lived between 18 million and 20 million years ago, and Cookeroo bulwidarri, dated to about 23 million years ago.
The bodies of these ancient kangaroos probably measured about 17 to 20 inches (approximately 42 to 52 centimeters) in length.
The Cookeroo bulwidarri and Cookeroo hortusensis were not hoppers like today’s kangaroo; they are believed to have navigated their forest home on their four feet and sharing it with a wide range of animals: feather-tailed possums, marsupial moles, ancient koalas, and even crocodiles.
Per the IUCN’s Red List of Species that are Threatened, there are 16 species of rat-kangaroos and tree-kangaroos that are listed as either threatened, near threatened, endangered, vulnerable, or critically endangered.
The Nullarbor dwarf bettong and the desert rat-kangaroo are now considered extinct species. Studies have revealed that global warming could also lead to the extinction of the world’s smallest kangaroo. Luckily, the four species of great kangaroos did not make it to the list of endangered animals.
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