Animals Wildlife 10 Incredible Facts About Kangaroos These iconic marsupials are more complex than you might think By Russell McLendon Russell McLendon Writer University of Georgia Russell McLendon is a science writer with expertise in the natural environment, humans, and wildlife. He holds degrees in journalism and environmental anthropology. Learn about our editorial process Updated April 26, 2022 Share Twitter Pinterest Email Jami Tarris / Getty Images Animals Wildlife Pets Animal Rights Endangered Species Few animals symbolize their continent quite like kangaroos, which serve as global icons for Australia. Despite their international fame, kangaroos are also commonly misunderstood, both at home and abroad. Did you know, for instance, that the animal we've come to revere as cute and cuddly is considered a pest by its human neighbors? They're widely disliked by farmers especially because they sneak into pastures and eat livestock feed. Of course, there are many things to like about these animals that counteract their unfavorable quirks. Here are 10 lesser-known facts about kangaroos. Fun Facts Common Name: KangarooScientific Name: MacropodidaeAverage Lifespan in the Wild: 8 yearsAverage Lifespan in Captivity: 25 yearsIUCN Red List Status: Least concernCurrent Population: Unknown 1. Kangaroos Are the Largest Marsupials on Earth Jami Tarris / Getty Images Kangaroos are the largest marsupials alive today. The largest species of kangaroo (by weight) is the red kangaroo, which can stand more than five feet tall—not including a three-foot-long tail—and weigh 180 pounds. Eastern gray kangaroos can be taller, with some adult males reaching nearly seven feet, but they're also leaner, only weighing up to 120 pounds. Red, eastern gray, and western gray kangaroos are the most common species. 2. They Come in Many Shapes and Sizes Tier Und Naturfotografie J und C Sohns / Getty Images Kangaroos belong to the genus Macropus, which means "large foot." Other members of that genus include several smaller but similar-looking species, but the distinction between them is not exceedingly clear. The smallest members of the genus are wallabies, while species of intermediate size are called wallaroos. The term "kangaroo" is sometimes used broadly for any of these animals, although it's generally reserved for the four largest: red, eastern gray, western gray, and antilopine kangaroos. It's also used for tree kangaroos, which belong to a different genus but are members of the wider taxonomic family known as macropods, which includes kangaroos, wallaroos, wallabies, tree kangaroos, pademelons, and quokkas. Outside the macropod family, tiny marsupials called rat kangaroos also bear a resemblance to their much larger relatives. 3. They're Left-Handed Humans and some other primates exhibit "handedness," or the tendency to use one hand more naturally than the other. Scientists once thought this was a unique feature of primate evolution, but more recent research suggests handedness is also common in kangaroos. Based on research with red kangaroos, eastern grays, and red-necked wallabies, researchers have found the animals are primarily left-handed, using that hand for tasks such as grooming and eating about 95% of the time. Their hands also seem to be specialized for different types of work, with kangaroos typically using their left hand for precision and their right for strength. This challenges the idea that handedness is unique to primates, researchers say, noting it may be an adaptation to bipedalism. 4. Together They're Called a Mob John Carnemolla / Getty Images Kangaroos travel and feed in groups known as mobs, troops, or herds. A kangaroo mob may include a handful or several dozen individuals, often with loose ties that allow shifting membership among mobs. Males may fight over females in mating season by kicking, boxing, or even biting, but the group tends to be dominated by its largest male. Male kangaroos are known as bucks, boomers, or jacks, while females are called does, flyers, or jills. 5. Some Can Hop 25 Feet Hopping is an energy-efficient way for kangaroos to move, helping them cover large distances in arid Australia as they search for food. They usually travel at moderate speeds, but they are capable of sprinting when necessary. A red kangaroo can hop at 35 mph, leap about six feet off the ground, and cover 25 feet in a single bound. 6. They Use Their Tails as a Fifth Leg When moving around smaller areas at a slower pace, kangaroos often incorporate their tail as a fifth leg. It may look awkward, but research on red kangaroos shows their big, muscular tails can provide as much propulsive force as their front and back legs combined. When a kangaroo needs to move more than about 15 feet, however, it usually skips the tail and starts hopping. 7. Joeys Can Go Dormant Until the Pouch Is Vacant Jennifer A. Smith / Getty Images The gestation period for kangaroos is about five weeks, after which they usually give birth to a single baby, known as a joey. No larger than a grape, the newborn joey must use its forelimbs to crawl through its mother's fur to her pouch. The joey will live in the pouch (called a marsupium) for the next several months as it continues to grow and develop. A female kangaroo can become pregnant again while a joey is still in her pouch, in which case the younger joey enters a dormant state until the pouch is vacant. Once the older sibling leaves her pouch, the mother kangaroo's body sends hormonal signals to resume the younger joey's development. 8. They Sometimes Drown Their Enemies Kangaroos don't have a lot of natural predators in Australia, especially now that large carnivores like thylacines and marsupial lions are extinct. A few animals are known to prey on kangaroos, however, typically targeting joeys or adults from smaller species. These predators include dingoes as well as introduced species such as red foxes, dogs, and feral cats. When a kangaroo does find itself pursued by a predator, it often flees toward water. This can just be an escape strategy, since kangaroos are surprisingly good swimmers (again, thanks to that massive tail). But in some cases, the prey might be leading its pursuer into a trap. Once a kangaroo is chest-deep in the water, it will sometimes turn around and confront the predator, grabbing it with its forelimbs and attempting to drown it. 9. Some May Sacrifice Joeys to Predators Ross Jardine / EyeEm / Getty Images Fighting back against predators may be less realistic for smaller kangaroos and other macropods like wallabies, wallaroos, and quokkas. Mother macropods have been known to drop their joeys and flee upon being chased by a predator. In one study, female quokkas caught in wire traps tried to escape when they saw a human approaching. In the commotion, their joeys often fell from the pouch. "Considering the muscular control that female quokkas have over the pouch opening ... it seems likely that this is a behavioral response rather than accidental," researchers wrote. (Worry not: The joeys were returned to their mothers' pouches.) This behavior has also been demonstrated by gray kangaroos and swamp wallabies. It might sound unthinkable to humans, but it could be an adaptive survival strategy, researchers suggest. Kangaroo mothers reproduce quicker than humans can, and when their lives are at stake, sacrificing one joey might be sensible—at least to them. 10. They Eat Grass Like Cows but Burp Less Methane Lea Scaddan / Getty Images All kangaroos are herbivores, grazing mainly on grasses but also some moss, shrubs, and fungi. Similar to cattle and other ruminant animals, kangaroos sometimes regurgitate their food and chew it as cud before digesting it. This isn't necessary for their digestion, though, and they only do it occasionally—maybe because it seems to cause them distress. Kangaroos' tube-shaped stomachs are very different from the four-chambered stomachs of ruminants. Cows infamously emit vast amounts of the potent greenhouse gas methane as they breathe and burp. But despite similar diets, kangaroos produce only about 27% of the body mass-specific volume of methane that ruminants produce. Food moves more quickly through kangaroo stomachs, and research suggests kangaroos' gut microbes are in a metabolic state more tuned for growth or biomass production than for making methane. Frequently Asked Questions How smart are kangaroos? Kangaroos have shown high-level cognition in studies, even finding ways to communicate with humans. When approached with a closed box of food, kangaroos in these studies have gazed intently at humans instead of attempting to open the box and access the food themselves. Are kangaroos aggressive? While you might have seen many a YouTube video of kangaroos "boxing" humans, they won't typically pick a fight unprovoked. They could approach people if they've been fed or domesticated in any way; ultimately, though, they have no business with humans and want to be left alone. Those that are aggressive are more likely larger males. Why do kangaroos lick their arms? Unique to kangaroos is a self-cooling system in which they lick their arms, and the moisture from their saliva cools the blood in small vessels just beneath the skin. This helps kangaroos regulate their body temperatures in Australia, where 90-degree summer days are common. Why are kangaroos culled in Australia? Kangaroo populations have grown in parts of Australia that have been deforested, therefore leaving land open for roos to graze. As their numbers increase, though, so, too, does the number killed by farmers each year. The government allows permit holders to cull kangaroos, which has resulted in what's been called the largest ever land-based wildlife slaughter on the planet. View Article Sources Giljov, Andrey et al. "Parallel Emergence Of True Handedness In The Evolution Of Marsupials And Placentals." Current Biology, vol 25, no. 14, 2015, pp. 1878-1884. Elsevier BV, doi:10.1016/j.cub.2015.05.043 O'Connor, Shawn M. et al. 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