Bio Facts: Kangaroo, Red
Australia and New Guinea
Wide ranging, from inland plains and grasslands to tropical rain forests and deserts
Red Kangaroos have a body length of around 65 inches, a tail length of 42 inches, and can weigh up to 198 lbs. Females are slightly smaller. They have short forelegs with sharp claws and large hind legs. Coat color varies from red to bluish gray.
12 to 18 years in the wild; up to 28 years in captivity
Females usually mature at about 2-3 years; males about 2 years.
In the wild, they eat a wide variety of grasses and low plants. In the Zoo, they are fed Omnivore diet, Monkey Chow, sweet potatoes, romaine lettuce, and apples.
Like antelope, kangaroos use speed as a defense. They can travel over long distances at 25 miles per hour and can run in short bursts at 30 to 40 miles per hour. When in search of food, kangaroos hop about 12 mph, taking 5 to 6.5 foot leaps. It is not exactly known how high kangaroos jump, but it is known that they can clear an 8 ft. fence from a standstill.
To cool themselves, kangaroos use evaporative cooling by licking the inside of their forearms where blood vessels are close to the skin. Kangaroos have flexible toes for grooming.
The herbivorous kangaroo spends its nights grazing. During the day it retires to the shade of a tree and remains inactive. When water is available, kangaroos will drink. Otherwise, kangaroos obtain sufficient moisture from the foods they eat, so drinking water daily is not necessary.
Red kangaroos fight when one male’s monopoly to a group of females is challenged. Before a fight begins, the two males walk “stiff-legged” before each other, scratching and grooming themselves. Standing upright on rear legs, the fight starts by the two locking forearms and pushing. Each kangaroo attempts to push the other backward to the ground. If one does not back down, the fighting may escalate. Using their tail to support their weight, they deliver kicks with their powerful hind legs. At this point, the loser will undoubtedly receive a mortal wound.
Breeding may diminish during times of drought or dry weather, but after a very short gestation period (33 days), the tiny kangaroo, about the size of a kidney bean (3/4” long and weighs less than an ounce), is born. It manages to climb up its mother’s coat into the marsupium, or pouch. Once inside, it latches onto a teat; the teat swells to fill the inside of the baby’s mouth. It suckles milk while its development continues.
Kangaroo babies, called joeys, spend the first 5 to 6 months of life protected in their mother’s pouch. They emerge looking just like their parents, only smaller. During the next 4 to 5 months, the joey spends more time away from the pouch, returning to its safety when it feels threatened. Joeys are weaned around 1 year of age, but will normally remain close to the mother for another 6 months or so. One young is the usual number born to each female, but twins are known.
Red kangaroos use their powerful hind legs and sharp claws for defense and can rip open a predator’s belly with one well-aimed blow.
Red kangaroos normally move in groups ranging from a few dozen to several hundred individuals, and are known as “mobs.” The makeup of the mob usually consists of a dominant male, a number of adult females, and juveniles of both sexes.
Their long, heavy tails are used for balance and support while hopping or standing.
Diapause: From the Greek “dia-“ and “pauein” meaning “to stop”, diapause is a forced state of inactivity between times of activity. After giving birth, a female marsupial mates and becomes pregnant almost immediately. The pouch, however, is “full.” While there is a baby suckling inside the pouch, hormones are released that cause the new embryo to enter a state of suspended animation. When suckling decreases (as a result of the baby spending more time outside of the pouch), different hormone levels trigger the embryo to continue its development. Soon a new baby is born and moves to the pouch to start the cycle all over again. This unique feature of the marsupial’s reproductive process makes this group of mammals very successful. A female can literally have three litters in various stages of maturation at the same time: one juvenile outside the pouch not yet independent, one inside the pouch nursing continuously, and one in diapause waiting for room in the pouch.
Females are able to produce two kinds of milk at the same time. A newborn gets clear fluid milk rich in nutrients and needed antibodies. An older sibling outside the pouch that nurses occasionally receives high fat milk. The two types of milk are delivered to different teats.
Not all red kangaroos are red. There are distinct regional differences in the coloring. In the eastern part of its range, males are usually red, while the females are a bluish gray. In other ranges, these trends may be reversed or both sexes may have the same reddish/brown coat.
Red kangaroos are the most common kangaroos found throughout continental Australia.
Red kangaroos have been known to travel as far as 26 feet in one jump.
The Greek root of the family name, Macropodidae, means, “big-footed.”
In 1863, John Gould warned, “I regret very much to say that the time may not be far distant when an opportunity of giving a full-sized drawing of the head of this noble animal, taken from life, will not be possible. The larger and more conspicuous productions of an island are often, as a natural consequence, the first to become extirpated.” Such was the case for the Tasmanian Thylacine and the Kangaroo Island Emu. Fortunately, the red kangaroo did not suffer this fate. As a result of human occupation in Australia, it has expanded its range because of the extensive development of artificial watering points across the most arid regions of the interior. Prior to European settlement, the red kangaroo only occurred east of the Dividing Range. Today, its status is listed as secure.
Jacksonville Zoo History:
Our earliest record of this species in the Jacksonville Zoological Garden’s animal collection is 1962, but a respected animal historian noted the presence of this species when he visited our Zoo during 1959.