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Kangaroos are
marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...
s from the family
Macropodidae Macropodidae is a Family (biology), family of marsupials that includes kangaroos, Wallaby, wallabies, tree-kangaroos, wallaroos, pademelons, quokkas, and several other groups. These genera are allied to the suborder Macropodiformes, containing ...
(macropods, meaning "large foot"). In common use, the term is used to describe the largest species from this family, the
red kangaroo The red kangaroo (''Osphranter rufus'') is the largest of all kangaroos, the largest terrestrial mammal native to Australia, and the Largest mammals#Marsupials (Marsupialia), largest extant marsupial. It is found across mainland Australia, exce ...
, as well as the
antilopine kangaroo The antilopine kangaroo (''Osphranter antilopinus''), also known as the antilopine wallaroo or the antilopine wallaby, is a species of Macropodidae, macropod found in northern Australia: in Cape York Peninsula in Queensland, the Top End of the N ...
,
eastern grey kangaroo The eastern grey kangaroo (''Macropus giganteus'': gigantic large-foot; also great grey kangaroo or forester kangaroo) is a marsupial found in the eastern third of Australia, with a population of several million. Although a large ''M. giganteus ...
, and
western grey kangaroo The western grey kangaroo (''Macropus fuliginosus''), also referred to as a western grey giant kangaroo, black-faced kangaroo, mallee kangaroo, sooty kangaroo and (when referring to the Kangaroo Island subspecies) Kangaroo Island grey kangaroo, i ...
. Kangaroos are indigenous to
Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
and
New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...
. The Australian government estimates that 42.8 million kangaroos lived within the commercial harvest areas of Australia in 2019, down from 53.2 million in 2013. As with the terms "
wallaroo Wallaroo is a common name for several species of moderately large macropods, intermediate in size between the kangaroos and the wallabies, that are native to Australia and Papua New Guinea. The word "wallaroo" is from the Dharug ''walaru'' wi ...
" and "
wallaby A wallaby () is a small or middle-sized Macropodidae, macropod native to Australia and New Guinea, with introduced populations in New Zealand, Hawaii, the United Kingdom and other countries. They belong to the same Taxonomy (biology), taxon ...
", "kangaroo" refers to a
paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...
grouping of species. All three terms refer to members of the same taxonomic family, Macropodidae, and are distinguished according to size. The largest species in the family are called "kangaroos" and the smallest are generally called "wallabies". The term "wallaroos" refers to species of an intermediate size. There are also the
tree-kangaroo Tree-kangaroos are marsupials of the genus ''Dendrolagus'', adapted for arboreal locomotion. They inhabit the tropical rainforests of New Guinea and far northeastern Queensland, Australia along with some of the islands in the region. All tree- ...
s, another type of macropod which inhabit the upper branches of trees in the
tropical rainforest Tropical rainforests are dense and warm rainforests with high rainfall typically found between 10° north and south of the Equator. They are a subset of the tropical forest biome that occurs roughly within the 28° latitudes (in the torrid zo ...
s of
New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...
, far northeastern
Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...
, and some of the islands in the region. A general idea of the relative size of these informal terms could be: *
wallabies A wallaby () is a small or middle-sized macropod native to Australia and New Guinea, with introduced populations in New Zealand, Hawaii, the United Kingdom and other countries. They belong to the same taxonomic family as kangaroos and som ...
: head and body length of 45–105 cm and tail length of 33–75 cm; the
dwarf wallaby ''Dorcopsulus'' is a genus of small marsupials in the family Macropodidae, known as forest wallabies. They are native to rainforests and montane forests of New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papu ...
(the smallest of all known macropod species) is 46 cm long and weighs 1.6 kg; *
tree-kangaroo Tree-kangaroos are marsupials of the genus ''Dendrolagus'', adapted for arboreal locomotion. They inhabit the tropical rainforests of New Guinea and far northeastern Queensland, Australia along with some of the islands in the region. All tree- ...
s: ranging from
Lumholtz's tree-kangaroo Lumholtz's tree-kangaroo (''Dendrolagus lumholtzi'') is a rare, long-tailed marsupial found in rainforests in northeastern Australia. Like most tree-kangaroos (genus ''Dendrolagus''), it lives alone in trees and feeds on plant matter. It belongs ...
: body and head length of 48–65 cm, tail of 60–74 cm, weight of for males and for females; to the
grizzled tree-kangaroo The grizzled tree-kangaroo (''Dendrolagus inustus'') is a furry, long-tailed mammal native to tropical rainforests on the island of New Guinea (split between Indonesia and Papua New Guinea). Like most tree-kangaroos (genus '' Dendrolagus''), it l ...
: length of and weight of ; *
wallaroo Wallaroo is a common name for several species of moderately large macropods, intermediate in size between the kangaroos and the wallabies, that are native to Australia and Papua New Guinea. The word "wallaroo" is from the Dharug ''walaru'' wi ...
s: the
black wallaroo The black wallaroo (''Osphranter bernardus''), also known as Woodward's wallaroo, is a species of macropod restricted to a small, mountainous area in Arnhem Land, Northern Territory, Australia, between South Alligator River and Nabarlek. It cl ...
(the smaller of the two species) with a tail length of 60–70 cm and weight of for males and for females; * kangaroos: a large male can be tall and weigh . Kangaroos have large, powerful
hind leg A hindlimb or back limb is one of the paired articulated appendages (limbs) attached on the caudal ( posterior) end of a terrestrial tetrapod vertebrate's torso.http://www.merriam-webster.com/medical/hind%20limb, Merriam Webster Dictionary-Hi ...
s, large feet adapted for leaping, a long muscular tail for balance, and a small head. Like most marsupials, female kangaroos have a pouch called a marsupium in which
joey Joey may refer to: People *Joey (name) Animals * Joey (marsupial), an infant marsupial * Joey, a blue-fronted Amazon parrot who was one of the Blue Peter pets Film and television * ''Joey'' (1977 film), an American film directed by Horace ...
s complete
postnatal The postpartum (or postnatal) period begins after childbirth and is typically considered to last for six to eight weeks. There are three distinct phases of the postnatal period; the acute phase, lasting for six to twelve hours after birth; the ...
development. Because of its grazing habits, the kangaroo has developed specialized teeth that are rare among mammals. Its
incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...
s are able to crop grass close to the ground and its molars chop and grind the grass. Since the two sides of the lower jaw are not joined or fused together, the lower incisors are farther apart, giving the kangaroo a wider bite. The
silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant f ...
in grass is abrasive, so kangaroo molars are ground down and they actually move forward in the mouth before they eventually fall out, and are replaced by new teeth that grow in the back. This process is known as
polyphyodont A polyphyodont is any animal whose tooth (animal), teeth are continually replaced. In contrast, diphyodonts are characterized by having only two successive sets of teeth. Polyphyodonts include most toothed fishes (most notably sharks), many repti ...
y and, amongst other mammals, only occurs in
elephant Elephants are the largest living land animals. Three living species are currently recognised: the African bush elephant ('' Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian elephant ('' Elephas maximus ...
s and
manatees Manatees (, family Trichechidae, genus ''Trichechus'') are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows. There are three accepted living species of Trichechidae, representing three of the four living spe ...
. The large kangaroos have adapted much better than the smaller macropods to land clearing for pastoral agriculture and habitat changes brought to the Australian landscape by humans. Many of the smaller species are rare and endangered, while kangaroos are relatively plentiful, despite a common misconception to the contrary. The kangaroo along with the
koala The koala (''Phascolarctos cinereus''), sometimes inaccurately called the koala bear, is an arboreal herbivorous marsupial native to Australia. It is the only Extant taxon, extant representative of the Family (biology), family ''Phascolar ...
are symbols of Australia. A kangaroo appears on the Australian coat of arms and on some of its
currency A currency is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes and coins. A more general definition is that a currency is a ''system of money'' in common use within a specific envi ...
, and is used as a logo for some of Australia's most well-known organisations, such as
Qantas Qantas ( ), formally Qantas Airways Limited, is the flag carrier of Australia, and the largest airline by fleet size, international flights, and international destinations in Australia and List of largest airlines in Oceania, Oceania. A foundi ...
, and as the
roundel A roundel is a circular disc used as a symbol. The term is used in heraldry, but also commonly used to refer to a type of national insignia used on military aircraft, generally circular in shape and usually comprising concentric rings of differ ...
of the
Royal Australian Air Force The Royal Australian Air Force (RAAF) is the principal Air force, aerial warfare force of Australia, a part of the Australian Defence Force (ADF) along with the Royal Australian Navy and the Australian Army. Constitutionally the Governor-Gener ...
. The kangaroo is important to both
Australian culture Australian culture is of primarily Western origins, and is derived from its British, Indigenous and migrant components. Indigenous peoples arrived as early as 60,000 years ago, and evidence of Aboriginal art in Australia dates back at least 3 ...
and the national image, and consequently there are numerous popular culture references. Wild kangaroos are shot for meat, leather hides, and to protect grazing land.
Kangaroo meat Kangaroo meat is produced in Australia from wild kangaroos and is exported to over 61 overseas markets. Kangaroo meat is sourced from the four main species of kangaroos that are harvested in the wild. As of May 2024, Australia’s commercial ka ...
has perceived health benefits for human consumption compared with traditional meats due to the low level of fat on kangaroos.


Terminology

The word ''kangaroo'' derives from the Guugu Yimithirr word ''gangurru'', referring to
eastern grey kangaroo The eastern grey kangaroo (''Macropus giganteus'': gigantic large-foot; also great grey kangaroo or forester kangaroo) is a marsupial found in the eastern third of Australia, with a population of several million. Although a large ''M. giganteus ...
s. The name was first recorded as "kanguru" on 12 July 1770 in an entry in the diary of Sir
Joseph Banks Sir Joseph Banks, 1st Baronet, (19 June 1820) was an English Natural history, naturalist, botanist, and patron of the natural sciences. Banks made his name on the European and American voyages of scientific exploration, 1766 natural-history ...
; this occurred at the site of modern
Cooktown Cooktown is a coastal town and locality in the Shire of Cook, Queensland, Australia. Cooktown is at the mouth of the Endeavour River, on Cape York Peninsula in Far North Queensland where James Cook beached his ship, the '' Endeavour'', for ...
, on the banks of the
Endeavour River The Endeavour River ( Guugu Yimithirr: ''Wabalumbaal''), inclusive of the Endeavour River Right Branch, the Endeavour River South Branch, and the Endeavour River North Branch, is a river system located on Cape York Peninsula in Far North Queens ...
, where under the command of Lieutenant
James Cook Captain (Royal Navy), Captain James Cook (7 November 1728 – 14 February 1779) was a British Royal Navy officer, explorer, and cartographer famous for his three voyages of exploration to the Pacific and Southern Oceans, conducted between 176 ...
was beached for almost seven weeks to repair damage sustained on the
Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system, composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...
. Cook first referred to kangaroos in his diary entry of 4 August. Guugu Yimithirr is the language of
the people The People may refer to: Legal jargon * The People, term used to refer to the people in general, in legal documents * "We the People of the United States", from the Preamble to the U. S. Constitution * In philosophy, economics, and political scienc ...
of the area. A common myth about the kangaroo's English name is that it was a Guugu Yimithirr phrase for "I don't know" or "I don't understand". According to this legend, Cook and Banks were exploring the area when they happened upon the animal. They asked a nearby local what the creatures were called. The local responded "kangaroo", said to mean "I don't know/understand", which Cook then took to be the name of the creature. Anthropologist
Walter Roth Walter Edmund Roth (2 April 1861 – 5 April 1933) was a British colonial administrator, anthropologist and medical practitioner, who worked in Queensland, Australia and British Guiana between 1898 and 1928. Roth and his brother, Henry Ling ...
was trying to correct this legend as far back as in 1898, but few took note until 1972 when linguist John B. Haviland in his research with the Guugu Yimithirr people was able to confirm that ''gangurru'' referred to a rare large dark-coloured species of kangaroo. However, when
Phillip Parker King Phillip Parker King (13 December 1791 – 26 February 1856) was an early explorer of the Australian and Patagonian coasts. Early life and education King was born on Norfolk Island, to Philip Gidley King and Anna Josepha King ''née'' Coo ...
visited the Endeavour River region in 1819 and 1820, he maintained that the local word was not ''kangaroo'' but ''menuah'' perhaps referring to a different species of macropod. There are similar, more credible stories of naming confusion, such as with the
Yucatán Peninsula The Yucatán Peninsula ( , ; ) is a large peninsula in southeast Mexico and adjacent portions of Belize and Guatemala. The peninsula extends towards the northeast, separating the Gulf of Mexico to the north and west of the peninsula from the C ...
. Kangaroos are often colloquially referred to as "roos". Male kangaroos are called bucks, boomers, jacks, or old men; females are does, flyers, or jills; and the young ones are
joey Joey may refer to: People *Joey (name) Animals * Joey (marsupial), an infant marsupial * Joey, a blue-fronted Amazon parrot who was one of the Blue Peter pets Film and television * ''Joey'' (1977 film), an American film directed by Horace ...
s. The
collective noun In linguistics, a collective noun is a word referring to a collection of things taken as a whole. Most collective nouns in everyday speech are not specific to one kind of thing. For example, the collective noun "group" can be applied to people (" ...
for a group of kangaroos is a mob, court, or troupe.


Taxonomy and description

There are four extant species that are commonly referred to as kangaroos: * The
red kangaroo The red kangaroo (''Osphranter rufus'') is the largest of all kangaroos, the largest terrestrial mammal native to Australia, and the Largest mammals#Marsupials (Marsupialia), largest extant marsupial. It is found across mainland Australia, exce ...
(''Osphranter rufus'') is the largest surviving
marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...
anywhere in the world. It occupies the arid and semi-arid centre of the country. The highest population densities of the red kangaroo occur in the rangelands of western New South Wales. Red kangaroos are commonly mistaken as the most abundant species of kangaroo, but eastern greys actually have a larger population. A large male can be tall and weigh . * The
eastern grey kangaroo The eastern grey kangaroo (''Macropus giganteus'': gigantic large-foot; also great grey kangaroo or forester kangaroo) is a marsupial found in the eastern third of Australia, with a population of several million. Although a large ''M. giganteus ...
(''Macropus giganteus'') is less well-known than the red (outside Australia), but the most often seen, as its range covers the fertile eastern part of the country. The range of the eastern grey kangaroo extends from the top of the
Cape York Peninsula The Cape York Peninsula is a peninsula located in Far North Queensland, Australia. It is the largest wilderness in northern Australia.Mittermeier, R.E. et al. (2002). Wilderness: Earth's last wild places. Mexico City: Agrupación Sierra Madre, ...
in northern Queensland down to Victoria, as well as areas of southeastern Australia and Tasmania. Population densities of eastern grey kangaroos usually peak near 100 per km2 in suitable habitats of open woodlands. Populations are more limited in areas of land clearance, such as farmland, where forest and woodland habitats are limited in size or abundance. * The
western grey kangaroo The western grey kangaroo (''Macropus fuliginosus''), also referred to as a western grey giant kangaroo, black-faced kangaroo, mallee kangaroo, sooty kangaroo and (when referring to the Kangaroo Island subspecies) Kangaroo Island grey kangaroo, i ...
(''Macropus fuliginosus'') is slightly smaller again at about for a large male. It is found in the southern part of Western Australia, South Australia near the coast, and the
Murray–Darling basin The Murray–Darling Basin is a large geographical area in the interior of southeastern Australia, encompassing the drainage basin of the tributaries of the Murray River, Australia's longest river, and the Darling River, a right tributary of ...
. The highest population densities occur in the western Riverina district of New South Wales and in the western areas of the Nullarbor Plain in Western Australia. Populations may have declined, particularly in agricultural areas. The species has a high tolerance to the plant toxin
sodium fluoroacetate Sodium fluoroacetate, also known by its trade name as a mammal poison compound 1080, is an organofluorine chemical compound with the chemical formula . It is the sodium salt of fluoroacetic acid, and contains sodium cations and fluoroacetate ...
, which indicates a possible origin from the southwest region of Australia. * The
antilopine kangaroo The antilopine kangaroo (''Osphranter antilopinus''), also known as the antilopine wallaroo or the antilopine wallaby, is a species of Macropodidae, macropod found in northern Australia: in Cape York Peninsula in Queensland, the Top End of the N ...
(''Osphranter antilopinus'') is, essentially, the far northern equivalent of the eastern grey and western grey kangaroos. It is sometimes referred to as the antilopine wallaroo, but in behaviour and habitat it is more similar to the red, eastern grey and western grey kangaroos. Like them, it is a creature of the grassy plains and woodlands, and gregarious. Its name comes from its fur, which is similar in colour and texture to that of antelopes. Characteristically, the noses of males swell behind the nostrils. This enlarges nasal passages and allows them to release more heat in hot and humid climates. In addition, there are about 50 smaller macropods closely related to the kangaroos in the family
Macropodidae Macropodidae is a Family (biology), family of marsupials that includes kangaroos, Wallaby, wallabies, tree-kangaroos, wallaroos, pademelons, quokkas, and several other groups. These genera are allied to the suborder Macropodiformes, containing ...
. Kangaroos and other macropods share a common ancestor with the
Phalangeridae The Phalangeridae are a family of mostly nocturnal marsupials native to Australia, New Guinea, and Eastern Indonesia, including the cuscuses, brushtail possums, and their close relatives. Considered a type of possum, most species are arboreal, a ...
from the Middle
Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
. This ancestor was likely arboreal and lived in the canopies of the extensive forests that covered most of Australia at that time, when the climate was much wetter, and fed on leaves and stems. From the Late Miocene through the Pliocene and into the
Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...
the climate got drier, which led to a decline of forests and expansion of grasslands. At this time, there was a radiation of macropodids characterised by enlarged body size and adaptation to the low quality grass diet with the development of
foregut fermentation Foregut fermentation is a form of digestion that occurs in the foregut of some animals such as the hamster rat, langur monkey, and the hippopotamus. It has evolved independently in several groups of mammals, and also in the hoatzin, a bird spe ...
. The most numerous early macropods, the
Balbaridae Balbaridae is an extinct family of basal Macropodoidea. The synapomorphies are divided into two areas, the dental and cranial. The dental area of this taxa can be described as having the molar lophodont and brachyodont with a hypo lophid fo ...
and the
Bulungamayinae Bulungamayinae is an extinct subfamily that allies fossil species of marsupials, showing close morphological features found in the modern potoroines, the bettongs and potoroos of Australia. The group possess characteristics of their dentition t ...
, became extinct in the Late Miocene around 5–10 mya. There is dispute over the relationships of the two groups to modern kangaroos and
rat-kangaroo Potoroidae is a family of marsupials, small Australian animals known as bettongs, potoroos, and rat-kangaroos. All are rabbit-sized, brown, jumping marsupials and resemble a large rodent or a very small wallaby. Taxonomy The potoroids are s ...
s. Some argue that the balbarines were the ancestors of rat-kangaroos and the bulungamayines were the ancestors of kangaroos. while others hold the contrary view. The middle to late bulungamayines, ''
Ganguroo ''Ganguroo'' is a genus of fossil macropods found at Riversleigh in Australia, material dating from the Middle to Late Miocene Epoch. The type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type specie ...
'' and ''Wanburoo'' lacked digit 1 of the hind foot and digits 2 and 3 were reduced and partly under the large digit 4, much like the modern kangaroo foot. This would indicate that they were bipedal. In addition, their ankle bones had an articulation that would have prohibited much lateral movements, an adaptation for bipedal hopping. Species related to the modern grey kangaroos and
wallaroo Wallaroo is a common name for several species of moderately large macropods, intermediate in size between the kangaroos and the wallabies, that are native to Australia and Papua New Guinea. The word "wallaroo" is from the Dharug ''walaru'' wi ...
s begin to appear in the Pliocene. The red kangaroo appears to be the most recently evolved kangaroo, with its fossil record not going back beyond the Pleistocene era, 1–2 mya. The first kangaroo to be exhibited in the Western world was an example shot by John Gore, an officer on Captain Cook's ship, HMS ''Endeavour'', in 1770. The animal was shot and its skin and skull transported back to England whereupon it was stuffed (by
taxidermists Taxidermy is the art of preserving an animal's body by mounting (over an armature) or stuffing, for the purpose of display or study. Animals are often, but not always, portrayed in a lifelike state. The word ''taxidermy'' describes the process ...
who had never seen the animal before) and displayed to the general public as a curiosity. The first glimpse of a kangaroo for many 18th-century Britons was a painting by
George Stubbs George Stubbs (25 August 1724 – 10 July 1806) was an English painter, best known for his paintings of horses. Self-trained, Stubbs learnt his skills independently from other great artists of the 18th century such as Joshua Reynolds and Thoma ...
.


Comparison with wallabies

Kangaroos and
wallabies A wallaby () is a small or middle-sized macropod native to Australia and New Guinea, with introduced populations in New Zealand, Hawaii, the United Kingdom and other countries. They belong to the same taxonomic family as kangaroos and som ...
belong to the same taxonomic family (
Macropodidae Macropodidae is a Family (biology), family of marsupials that includes kangaroos, Wallaby, wallabies, tree-kangaroos, wallaroos, pademelons, quokkas, and several other groups. These genera are allied to the suborder Macropodiformes, containing ...
) and often the same genera, but kangaroos are specifically categorised into the four largest species of the family. The term wallaby is an informal designation generally used for any macropod that is smaller than a kangaroo or a
wallaroo Wallaroo is a common name for several species of moderately large macropods, intermediate in size between the kangaroos and the wallabies, that are native to Australia and Papua New Guinea. The word "wallaroo" is from the Dharug ''walaru'' wi ...
that has not been designated otherwise.


Biology and behaviour


Locomotion

Kangaroos are the only large mammals to use hopping on two legs as their primary means of locomotion. The comfortable hopping speed for a red kangaroo is about , but speeds of up to can be attained over short distances, while it can sustain a speed of for nearly . During a hop, the powerful
gastrocnemius muscle The gastrocnemius muscle (plural ''gastrocnemii'') is a superficial two-headed muscle that is in the back part of the lower leg of humans. It is located superficial to the soleus in the posterior (back) compartment of the leg. It runs from its t ...
s lift the body off the ground while the smaller
plantaris muscle The plantaris is one of the superficial muscles of the superficial posterior compartment of the leg, one of the fascial compartments of the leg. It is composed of a thin muscle belly and a long thin tendon. While not as thick as the achilles te ...
, which attaches near the large fourth toe, is used for push-off. Seventy percent of potential energy is stored in the elastic tendons. At slow speeds, it employs pentapedal locomotion, using its tail to form a tripod with its two
forelimb A forelimb or front limb is one of the paired articulated appendages ( limbs) attached on the cranial (anterior) end of a terrestrial tetrapod vertebrate's torso. With reference to quadrupeds, the term foreleg or front leg is often used inst ...
s while bringing its hind feet forward. Both pentapedal walking and fast hopping are energetically costly. Hopping at moderate speeds is the most energy efficient, and a kangaroo moving above maintains energy consistency more than similarly sized animals running at the same speed.


Diet

Kangaroos have single-chambered stomachs quite unlike those of
cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...
and
sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...
, which have four compartments. They sometimes regurgitate the vegetation they have eaten, chew it as
cud Cud is a portion of food that returns from a ruminant's stomach to the mouth to be chewed for the second time. More precisely, it is a bolus of semi-degraded food regurgitated from the reticulorumen of a ruminant. Cud is produced during the phy ...
, and then swallow it again for final digestion. However, this is a different, more strenuous, activity than it is in
ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...
s, and does not take place as frequently. Different species of kangaroos have different diets, although all are strict
herbivores A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...
. The eastern grey kangaroo is predominantly a grazer, and eats a wide variety of grasses, whereas some other species such as the red kangaroo include significant amounts of
shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...
s in their diets. Smaller species of kangaroos also consume
hypogeal Hypogeal, hypogean, hypogeic and hypogeous (; ) are biological terms describing an organism's activity below the soil surface. In botany, a seed is described as showing hypogeal germination when the cotyledons of the germinating seed remain no ...
fungi. Many species are
nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...
, and
crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal (active during dawn), vespertine (biology), vespertine/vespertinal (active during dusk), or both. This is distinguished from diurnalit ...
, usually spending the hot days resting in shade, and the cool evenings, nights and mornings moving about and feeding.


Absence of digestive methane release

Despite having herbivorous diets similar to
ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...
s such as cattle, which release large quantities of digestive
methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes ...
through exhaling and
eructation Burping (also called belching and eructation) is the release of gas from the upper digestive tract (esophagus and stomach) of animals through the mouth. It is usually audible. In humans, burping can be caused by normal eating processes, or as ...
(burping), kangaroos release virtually none. The
hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
byproduct of
fermentation Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and reduce ...
is instead converted into
acetate An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...
, which is then used to provide further energy. Scientists are interested in the possibility of transferring the bacteria responsible for this process from kangaroos to cattle, since the
greenhouse gas Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...
effect of methane is 23 times greater than
carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...
per molecule.


Social and sexual behavior

Groups of kangaroos are called ''mobs'', ''courts'' or ''troupes'', which usually have 10 or more kangaroos in them. Living in mobs can provide protection for some of the weaker members of the group. The size and stability of mobs vary between geographic regions, with eastern Australia having larger and more stable aggregations than in arid areas farther west. Larger aggregations display high amounts of interactions and complex social structures, comparable to that of
ungulate Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...
s. One common behavior is nose touching and sniffing, which mostly occurs when an individual joins a group. The kangaroo performing the sniffing gains much information from smell cues. This behavior enforces social cohesion without consequent aggression. During mutual sniffing, if one kangaroo is smaller, it will hold its body closer to the ground and its head will quiver, which serves as a possible form of submission. Greetings between males and females are common, with larger males being the most involved in meeting females. Most other non-antagonistic behavior occurs between mothers and their young. Mother and young reinforce their bond through grooming. A mother will groom her young while it is suckling or after it is finished suckling. A joey will nuzzle its mother's pouch if it wants access to it.
Sexual activity Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts, ranging from activities done alone (e.g., masturbation) t ...
of kangaroos consists of consort pairs.
Oestrous The estrous cycle (, originally ) is a set of recurring physiological changes induced by reproductive hormones in females of mammalian subclass Theria. Estrous cycles start after sexual maturity in females and are interrupted by anestrous phases ...
females roam widely and attract the attention of males with conspicuous signals. A male will monitor a female and follow her every movement. He sniffs her urine to see if she is in oestrus, a process exhibiting the
flehmen response The flehmen response (; from German , and Upper Saxon German ), also called the flehmen position, flehmen reaction, flehmen grimace, flehming, or flehmening, is a behavior in which an animal curls back its upper lip exposing its front teeth, i ...
. The male will then proceed to approach her slowly to avoid alarming her. If the female does not run away, the male will continue by licking, pawing, and scratching her, and
copulation Sexual intercourse (also coitus or copulation) is a sexual activity typically involving the insertion of the erect male penis inside the female vagina and followed by thrusting motions for sexual pleasure, reproduction, or both.Sexual inte ...
will follow. After copulation is over, the male will move on to another female. Consort pairing may take several days and the copulation is also long. Thus, a consort pair is likely to attract the attention of a rival male. As larger males are tending bonds with females near oestrus, smaller males will tend to females that are farther from oestrus. Dominant males can avoid having to sort through females to determine their reproductive status by searching for tending bonds held by the largest male they can displace without a fight. Fighting has been described in all species of kangaroos. Fights between kangaroos can be brief or long and ritualised. In highly competitive situations, such as males fighting for access to oestrous females or at limited drinking spots, the fights are brief. Both sexes will fight for drinking spots, but long, ritualised fighting or "boxing" is largely done by males. Smaller males fight more often near females in oestrus, while the large males in consorts do not seem to get involved. Ritualised fights can arise suddenly when males are grazing together. However, most fights are preceded by two males scratching and grooming each other. One or both of them will adopt a high standing posture, with one male issuing a challenge by grasping the other male's neck with its forepaw. Sometimes, the challenge will be declined. Large males often reject challenges by smaller males. During fighting, the combatants adopt a high standing posture and paw at each other's heads, shoulders and chests. They will also lock forearms and wrestle and push each other as well as balance on their tails to kick each other in the abdomen. Brief fights are similar, except there is no forearm locking. The losing combatant seems to use kicking more often, perhaps to parry the thrusts of the eventual winner. A winner is decided when a kangaroo breaks off the fight and retreats. Winners are able to push their opponents backwards or down to the ground. They also seem to grasp their opponents when they break contact and push them away. The initiators of the fights are usually the winners. These fights may serve to establish dominance hierarchies among males, as winners of fights have been seen to displace their opponent from resting sites later in the day. Dominant males may also pull grass to intimidate subordinate ones.


Predators

Kangaroos have a few natural
predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...
s. The
thylacine The thylacine (; binomial name ''Thylacinus cynocephalus''), also commonly known as the Tasmanian tiger or Tasmanian wolf, was a carnivorous marsupial that was native to the Mainland Australia, Australian mainland and the islands of Tasmani ...
, considered by palaeontologists to have once been a major natural predator of the kangaroo, is now
extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
. Other extinct predators included the marsupial lion, ''
Megalania Megalania (''Varanus priscus'') is an extinct species of giant monitor lizard, part of the megafaunal assemblage that inhabited Australia during the Pleistocene. It is the largest terrestrial lizard known to have existed, but the fragmentary na ...
'' and ''
Wonambi ''Wonambi'' is an extinct genus of madtsoiid snakes that lived in late Neogene to late Quaternary Australia. Species of ''Wonambi'' were constrictor snakes unrelated to Australian pythons. Taxonomy and naming ''Wonambi naracoortensis'' was ...
''. However, with the arrival of humans in Australia at least 50,000 years ago and the introduction of the
dingo The dingo (either included in the species ''Canis familiaris'', or considered one of the following independent taxa: ''Canis familiaris dingo'', ''Canis dingo'', or ''Canis lupus dingo'') is an ancient (basal (phylogenetics), basal) lineage ...
about 5,000 years ago, kangaroos have had to adapt. Along with dingoes,
introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...
such as foxes,
feral cat A feral cat or a stray cat is an unowned domestic cat (''Felis catus'') that lives outdoors and avoids human contact; it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens ...
s, and both domestic and feral dogs, pose a threat to kangaroo populations. Kangaroos and wallabies are adept
swimmers Swimming is an individual or team racing sport that requires the use of one's entire body to move through water. The sport takes place in pools or open water (e.g., in a sea or lake). Competitive swimming is one of the most popular Olympic ...
, and often flee into waterways if presented with the option. If pursued into the water, a large kangaroo may use its forepaws to hold the predator underwater so as to
drown Drowning is a type of suffocation induced by the submersion of the mouth and nose in a liquid. Submersion injury refers to both drowning and near-miss incidents. Most instances of fatal drowning occur alone or in situations where others presen ...
it. Another defensive
tactic Tactic(s) or Tactical may refer to: * Tactic (method), a conceptual action implemented as one or more specific tasks ** Military tactics, the disposition and maneuver of units on a particular sea or battlefield ** Chess tactics ** Political tacti ...
described by witnesses is catching the attacking dog with the forepaws and
disembowel Disembowelment, disemboweling, evisceration, eviscerating or gutting is the removal of organs from the gastrointestinal tract (bowels or viscera), usually through an incision made across the abdominal area. Disembowelment is a standard routin ...
ling it with the hind legs.


Adaptations

Kangaroos have developed a number of adaptations to a dry, infertile country and highly variable climate. As with all
marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...
s, the young are born at a very early stage of development—after a
gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...
of 31–36 days. At this stage, only the forelimbs are somewhat developed, to allow the newborn to climb to the pouch and attach to a
teat A teat is the projection from the mammary glands of mammals from which milk flows or is ejected for the purpose of feeding young. In many mammals, the teat projects from the udder. The number of teats varies by mammalian species and often corr ...
. In comparison, a human
embryo An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ...
at a similar stage of development would be at about 7 weeks gestation (even in a modern intensive care unit,
premature babies Preterm birth, also known as premature birth, is the birth of a baby at fewer than 37 weeks gestational age, as opposed to full-term delivery at approximately 40 weeks. Extreme preterm is less than 28 weeks, very early preterm birth is betwee ...
born at less than 23 weeks gestation are usually not mature enough to survive). When the joey is born, it is about the size of a
lima bean A lima bean (''Phaseolus lunatus''), also commonly known as butter bean, sieva bean, double bean or Madagascar bean, is a legume grown for its edible seeds or beans. Origin and uses ''Phaseolus lunatus'' is found in Meso- and South America. Tw ...
. The joey will usually stay in the pouch for about 9 months (180–320 days for the Western Grey) before starting to leave the pouch for small periods of time. It is usually fed by its mother until reaching 18 months. The female kangaroo is usually pregnant in permanence, except on the day she gives birth; however, she has the ability to freeze the development of an embryo until the previous
joey Joey may refer to: People *Joey (name) Animals * Joey (marsupial), an infant marsupial * Joey, a blue-fronted Amazon parrot who was one of the Blue Peter pets Film and television * ''Joey'' (1977 film), an American film directed by Horace ...
is able to leave the pouch. This is known as
embryonic diapause Embryonic diapause (delayed implantation in mammals) is a reproductive strategy used by a number of animal species across different biological classes. In more than 130 types of mammals where this takes place, the process occurs at the blastocys ...
and will occur in times of drought and in areas with poor food sources. The composition of the milk produced by the mother varies according to the needs of the joey. In addition, the mother is able to produce two different kinds of milk simultaneously for the newborn and the older joey still in the pouch. Unusually, during a dry period, males will not produce sperm and females will conceive only if enough rain has fallen to produce a large quantity of green vegetation. Kangaroos and wallabies have large, elastic tendons in their hind legs. They store elastic strain energy in the
tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...
s of their large hind legs, providing most of the energy required for each hop by the spring action of the tendons rather than by any muscular effort. This is true in all animal species which have muscles connected to their skeletons through elastic elements such as tendons, but the effect is more pronounced in kangaroos. There is also a link between the hopping action and breathing: as the feet leave the ground, air is expelled from the lungs; bringing the feet forward ready for landing refills the lungs, providing further energy efficiency. Studies of kangaroos and
wallabies A wallaby () is a small or middle-sized macropod native to Australia and New Guinea, with introduced populations in New Zealand, Hawaii, the United Kingdom and other countries. They belong to the same taxonomic family as kangaroos and som ...
have demonstrated, beyond the minimum energy expenditure required to hop at all, increased speed requires very little extra effort (much less than the same speed increase in, say, a horse, dog or human), and the extra energy is required to carry extra weight. For kangaroos, the key benefit of hopping is not speed to escape predators—the top speed of a kangaroo is no higher than that of a similarly sized quadruped, and the Australian native predators are in any case less fearsome than those of other countries—but economy: in an infertile country with highly variable weather patterns, the ability of a kangaroo to travel long distances at moderately high speed in search of food sources is crucial to survival. New research has revealed that a kangaroo's tail acts as a third leg rather than just a balancing strut. Kangaroos have a unique three-stage walk where they plant their front legs and tail first, then push off their tail, followed lastly by the back legs. The propulsive force of the tail is equal to that of both the front and hind legs combined and performs as much work as what a human leg walking can at the same speed. A
DNA sequencing DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, thymine, cytosine, and guanine. The ...
project of the
genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...
of a member of the kangaroo family, the
tammar wallaby The tammar wallaby (''Notamacropus eugenii''), also known as the dama wallaby or darma wallaby, is a small macropod native to South and Western Australia. Though its geographical range has been severely reduced since European colonisation, the ...
, was started in 2004. It was a collaboration between Australia (mainly funded by the
State of Victoria Victoria, commonly abbreviated as Vic, is a state in southeastern Australia. It is the second-smallest state (after Tasmania), with a land area of ; the second-most-populated state (after New South Wales), with a population of over 7 million; ...
) and the
National Institutes of Health The National Institutes of Health (NIH) is the primary agency of the United States government responsible for biomedical and public health research. It was founded in 1887 and is part of the United States Department of Health and Human Service ...
in the US. The tammar's genome was fully sequenced in 2011. The genome of a marsupial such as the kangaroo is of great interest to scientists studying
comparative genomics Comparative genomics is a branch of biological research that examines genome sequences across a spectrum of species, spanning from humans and mice to a diverse array of organisms from bacteria to chimpanzees. This large-scale holistic approach c ...
, because marsupials are at an ideal degree of evolutionary divergence from humans:
mice A mouse (: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
are too close and have not developed many different functions, while birds are genetically too remote. The dairy industry could also benefit from this project.


Blindness

Eye disease is rare but not new among kangaroos. The first official report of kangaroo blindness took place in 1994, in central
New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...
. The following year, reports of blind kangaroos appeared in Victoria and South Australia. By 1996, the disease had spread "across the desert to Western Australia". Australian authorities were concerned the disease could spread to other livestock and possibly humans. Researchers at the Australian Animal Health Laboratories in
Geelong Geelong ( ) (Wathawurrung language, Wathawurrung: ''Djilang''/''Djalang'') is a port city in Victoria, Australia, located at the eastern end of Corio Bay (the smaller western portion of Port Phillip Bay) and the left bank of Barwon River (Victo ...
detected a virus called the Wallal virus in two species of
midge A midge is any small fly, including species in several family (biology), families of non-mosquito nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid ...
s, believed to have been the carriers.
Veterinarians A veterinarian (vet) or veterinary surgeon is a medical professional who practices veterinary medicine. They manage a wide range of health conditions and injuries in non-human animals. Along with this, veterinarians also play a role in animal r ...
also discovered fewer than 3% of kangaroos exposed to the virus developed blindness.


Reproduction and life cycle

Kangaroo reproduction is similar to that of
opossum Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North A ...
s. The egg (still contained in the shell membrane, a few micrometres thick, and with only a small quantity of yolk within it) descends from the
ovary The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...
into the
uterus The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...
. There it is fertilised and quickly develops into a
neonate In common terminology, a baby is the very young offspring of adult human beings, while infant (from the Latin word ''infans'', meaning 'baby' or 'child') is a formal or specialised synonym. The terms may also be used to refer to Juvenile (orga ...
. Even in the largest kangaroo species (the
red kangaroo The red kangaroo (''Osphranter rufus'') is the largest of all kangaroos, the largest terrestrial mammal native to Australia, and the Largest mammals#Marsupials (Marsupialia), largest extant marsupial. It is found across mainland Australia, exce ...
), the neonate emerges after only 33 days. Usually, only one young is born at a time. It is blind, hairless, and only a few centimetres long; its hindlegs are mere stumps; it instead uses its more developed forelegs to climb its way through the thick fur on its mother's
abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...
into the pouch, which takes about three to five minutes. Once in the pouch, it fastens onto one of the four teats and starts to feed. Almost immediately, the mother's sexual cycle starts again. Another egg descends into the uterus and she becomes sexually receptive. Then, if she mates and a second egg is fertilised, its development is temporarily halted. This is known as
embryonic diapause Embryonic diapause (delayed implantation in mammals) is a reproductive strategy used by a number of animal species across different biological classes. In more than 130 types of mammals where this takes place, the process occurs at the blastocys ...
, and will occur in times of drought and in areas with poor food sources. Meanwhile, the neonate in the pouch grows rapidly. After about 190 days, the baby (
joey Joey may refer to: People *Joey (name) Animals * Joey (marsupial), an infant marsupial * Joey, a blue-fronted Amazon parrot who was one of the Blue Peter pets Film and television * ''Joey'' (1977 film), an American film directed by Horace ...
) is sufficiently large and developed to make its full emergence out of the pouch, after sticking its head out for a few weeks until it eventually feels safe enough to fully emerge. From then on, it spends increasing time in the outside world and eventually, after about 235 days, it leaves the pouch for the last time. The lifespan of kangaroos averages at six years in the wild to in excess of 20 years in captivity, varying by the species. Most individuals, however, do not reach maturity in the wild.


Interaction with humans

The kangaroo has always been a very important animal for
Aboriginal Australians Aboriginal Australians are the various indigenous peoples of the Mainland Australia, Australian mainland and many of its islands, excluding the ethnically distinct people of the Torres Strait Islands. Humans first migrated to Australia (co ...
, for its
meat Meat is animal Tissue (biology), tissue, often muscle, that is eaten as food. Humans have hunted and farmed other animals for meat since prehistory. The Neolithic Revolution allowed the domestication of vertebrates, including chickens, sheep, ...
, hide, bone, and
tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...
. Kangaroo hides were also sometimes used for recreation; in particular there are accounts of some tribes (
Kurnai The Kurnai () people Aboriginal Australian nation of south-east Australia. They are the Traditional Custodians of most of present-day Gippsland and much of the southern slopes of the Victorian Alps. The Kurnai nation is composed of five major ...
) using stuffed
kangaroo scrotum Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...
as a ball for the traditional football game of
marngrook , or (also spelt ''Marn Gook'') is the popular collective name for traditional Indigenous Australian football games played at gatherings and celebrations by sometimes more than 100 players. From the Woiwurung language of the Kulin people, ...
. In addition, there were important Dreaming stories and ceremonies involving the kangaroo. Aherrenge is a current kangaroo dreaming site in the
Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...
. Unlike many of the smaller macropods, kangaroos have fared well since European settlement. European settlers cut down forests to create vast grasslands for
sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...
and cattle grazing, added stock watering points in arid areas, and have substantially reduced the number of dingoes. This overabundance has led to the view that the kangaroo is a pest animal as well as requiring regular culling and other forms of management. There is concern that the current management practices are leading to detrimental consequences for kangaroo welfare, landscape sustainability, biodiversity conservation, resilient agricultural production and Aboriginal health and culture. Kangaroos are shy and retiring by nature, and in normal circumstances present no threat to humans. In 2003, Lulu, an eastern grey which had been hand-reared, saved a farmer's life by alerting family members to his location when he was injured by a falling tree branch. She received the
RSPCA Australia RSPCA Australia (Royal Society for the Prevention of Cruelty to Animals) is an Australian peak organisation established in 1981 to promote animal welfare. Each state and territory of Australia has an RSPCA organisation that predates and is ...
National Animal Valour Award on 19 May 2004. There are very few records of kangaroos attacking humans without provocation; however, several such unprovoked attacks in 2004 spurred fears of a
rabies Rabies is a viral disease that causes encephalitis in humans and other mammals. It was historically referred to as hydrophobia ("fear of water") because its victims panic when offered liquids to drink. Early symptoms can include fever and abn ...
-like disease possibly affecting the marsupials. Only two reliably documented cases of a fatality from a kangaroo attack have occurred in Australia. The first attack occurred in New South Wales in 1936 when a hunter was killed as he tried to rescue his two dogs from a heated fray. The second attack was inflicted on a 77-year-old man from a domesticated kangaroo in
Redmond, Western Australia Redmond is a town and locality of the City of Albany in the Great Southern region of Western Australia. It is located 399 km south-south-east of Perth and the closest populated town is Albany. The town began when a railway siding was o ...
in September 2022. Other suggested causes for erratic and dangerous kangaroo behaviour include extreme thirst and hunger. In July 2011, a male red kangaroo attacked a 94-year-old woman in her own backyard as well as her son and two police officers responding to the situation. The kangaroo was capsicum sprayed (pepper sprayed) and later put down after the attack. Kangaroos—even those that are not domesticated— can communicate with humans, according to a research study.


Collisions with vehicles

Nine out of ten animal collisions in Australia involve kangaroos. A collision with a vehicle is capable of killing a kangaroo. Kangaroos dazzled by headlights or startled by engine noise often leap in front of cars. Since kangaroos in mid-bound can reach speeds of around and are relatively heavy, the force of impact can be severe. Small vehicles may be destroyed, while larger vehicles may suffer engine damage. The risk of harm or death to vehicle occupants is greatly increased if the
windscreen The windshield (American English and Canadian English) or windscreen (Commonwealth English) of an aircraft, car, bus, motorbike, truck, train, boat or streetcar is the front window, which provides visibility while protecting occupants from t ...
is the point of impact. As a result, "kangaroo crossing" signs are commonplace in Australia. Vehicles that frequent isolated roads, where roadside assistance may be scarce, are often fitted with " roo bars" to minimise damage caused by collision.
Bonnet A bonnet is a variety of headgear, hat or cap. Specific types of headgear referred to as "bonnets" may include Native American *War bonnet, feathered headgear worn as an earned military decoration by high-ranking Plains Indians United King ...
-mounted devices, designed to scare wildlife off the road with
ultrasound Ultrasound is sound with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...
and other methods, have been devised and marketed, but are ineffective. If a female is the victim of a collision, animal welfare groups ask that her pouch be checked for any surviving joey, in which case it may be removed to a wildlife sanctuary or veterinary surgeon for rehabilitation. Likewise, when an adult kangaroo is injured in a collision, a vet, the
RSPCA Australia RSPCA Australia (Royal Society for the Prevention of Cruelty to Animals) is an Australian peak organisation established in 1981 to promote animal welfare. Each state and territory of Australia has an RSPCA organisation that predates and is ...
or the National Parks and Wildlife Service can be consulted for instructions on proper care. In New South Wales, rehabilitation of kangaroos is carried out by volunteers from WIRES. Council road signs often list phone numbers for callers to report injured animals.


Emblems and popular culture

The kangaroo is a recognisable symbol of Australia. The kangaroo and
emu The emu (; ''Dromaius novaehollandiae'') is a species of flightless bird endemism, endemic to Australia, where it is the Tallest extant birds, tallest native bird. It is the only extant taxon, extant member of the genus ''Dromaius'' and the ...
feature on the Australian coat of arms. Kangaroos have also been featured on coins, most notably the five kangaroos on the
Australian one dollar coin The Australian one-dollar coin is the second most valuable circulation denomination coin of the Australian dollar after the two-dollar coin; there are also non-circulating legal-tender coins of higher denominations (five-, ten-, and two-hundre ...
. The
Australian Made logo The Australian Made, Australian Grown logo (also known as the Australian Made logo or AMAG logo) is a registered certification Collective trade mark, trade mark logo and country of origin label that certifies that a product has been manufactured ...
consists of a golden kangaroo in a green triangle to show that a product is grown or made in Australia. Registered
trademark A trademark (also written trade mark or trade-mark) is a form of intellectual property that consists of a word, phrase, symbol, design, or a combination that identifies a Good (economics and accounting), product or Service (economics), service f ...
s of early Australian companies using the kangaroo included Yung, Schollenberger & Co. Walla Walla Brand leather and skins (1890); Arnold V. Henn (1892) whose emblem showed a family of kangaroos playing with a
skipping rope A skipping rope (or jump rope) is a tool used in a sport involving rhythmic jumping over a rope swung underfoot and overhead. The activity, practiced both recreationally and competitively, encompasses disciplines such as freestyle routines—f ...
; Robert Lascelles & Co. linked the speed of the animal with its
velocipede A velocipede () is a human-powered land vehicle with one or more wheels. The most common type of velocipede today is the bicycle. The term was probably first coined by Karl von Drais in French as ''vélocipède'' for the French translation ...
s (1896); while some overseas manufacturers, like that of "The Kangaroo"
safety matches A match is a tool for starting a fire. Typically, matches are made of small wooden sticks or stiff paper. One end is coated with a material that can be ignited by friction generated by striking the match against a suitable surface. Wooden matc ...
(made in Japan) of the early 1900s, also adopted the symbol. Even today, Australia's national airline,
Qantas Qantas ( ), formally Qantas Airways Limited, is the flag carrier of Australia, and the largest airline by fleet size, international flights, and international destinations in Australia and List of largest airlines in Oceania, Oceania. A foundi ...
, uses a bounding kangaroo for its logo. The kangaroo appears in
Rudyard Kipling Joseph Rudyard Kipling ( ; 30 December 1865 – 18 January 1936)''The Times'', (London) 18 January 1936, p. 12. was an English journalist, novelist, poet, and short-story writer. He was born in British Raj, British India, which inspired much ...
's ''
Just So Stories ''Just So Stories for Little Children'' is a 1902 collection of origin stories by the British author Rudyard Kipling. Considered a classic of children's literature, the book is among Kipling's best known works. Kipling began working on the ...
'', "
The Sing-Song of Old Man Kangaroo "The Sing-Song of Old Man Kangaroo" is a short story — one of the ''Just So'' stories by Rudyard Kipling. The story was first told aloud by the author to his daughter Josephine as part of their oral tradition. It was then written down and f ...
", while the kangaroo is chased by a dingo, he gives Nqong the Big God's advice, that his legs and tail grew longest before five o'clock. The kangaroo and wallaby feature predominantly in Australian sports teams names and mascots. Examples include the
Australian national rugby league team The Australian national rugby league team, the Kangaroos, have represented Australia in senior men's rugby league football competitions since the establishment of the game in Australia in 1908. Administered by the Australian Rugby League Comm ...
(the Kangaroos) and the
Australian national rugby union team The Australia men's national rugby union team, nicknamed the Wallabies, is the representative men's national team in the sport of rugby union for Australia. The Wallabies first played at Sydney in 1899, winning their first test match against ...
(the Wallabies). In a nation-wide competition held in 1978 for the XII Commonwealth Games by the Games Australia Foundation Limited in 1982, Hugh Edwards' design was chosen; a simplified form of six thick stripes arranged in pairs extending from along the edges of a triangular centre represent both the kangaroo in full flight, and a stylised "A" for Australia. Kangaroos are well represented in films, television, books, toys and souvenirs around the world. ''
Skippy the Bush Kangaroo ''Skippy the Bush Kangaroo'' (known commonly as ''Skippy'') is an Australian television series created by Australian actor John McCallum, Lionel (Bob) Austin, and Lee Robinson, produced from 1967 to 1969 (airing from 5 February 1968 to 4 May 1 ...
'' was a popular 1960s Australian children's television series about a fictional pet kangaroo. Kangaroos are featured in the
Rolf Harris Rolf Harris (30 March 1930 – 10 May 2023) was an Australian musician, television personality, painter, and actor. He used a variety of instruments in his performances, notably the didgeridoo and the Stylophone, and is credited with the inventi ...
song "
Tie Me Kangaroo Down, Sport "Tie Me Kangaroo Down, Sport" is a song written by Australian singer Rolf Harris in 1957 which became a hit around the world in the 1960s in two recordings (1960 in Australia, New Zealand and the United Kingdom for the original, and 1963 in th ...
" and several Christmas carols.


Meat

The kangaroo has been a source of food for
indigenous Australians Indigenous Australians are people with familial heritage from, or recognised membership of, the various ethnic groups living within the territory of contemporary Australia prior to History of Australia (1788–1850), British colonisation. The ...
for tens of thousands of years. Kangaroo meat is high in
protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
and low in fat (about 2%). Kangaroo meat has a high concentration of
conjugated linoleic acid Conjugated linoleic acids (CLA) are a family of isomers of linoleic acid. In principle, 28 isomers are possible. CLA is found mostly in the meat and dairy products derived from ruminants. The two C=C double bonds are conjugated (i.e., separated ...
(CLA) compared with other foods, and is a rich source of vitamins and minerals. Low fat diets rich in CLA have been studied for their potential in reducing obesity and atherosclerosis. Kangaroo meat is sourced from wild animals and is seen by many as the best source of population control programs as opposed to culling them as pests where carcasses are left in paddocks. Kangaroos are harvested by licensed shooters in accordance with a code of practice and are protected by state and federal legislation. Kangaroo meat is exported to many countries around the world. However, it is not considered biblically
kosher (also or , ) is a set of dietary laws dealing with the foods that Jewish people are permitted to eat and how those foods must be prepared according to Jewish law. Food that may be consumed is deemed kosher ( in English, ), from the Ashke ...
by
Jews Jews (, , ), or the Jewish people, are an ethnoreligious group and nation, originating from the Israelites of History of ancient Israel and Judah, ancient Israel and Judah. They also traditionally adhere to Judaism. Jewish ethnicity, rel ...
or
Adventists Adventism is a branch of Protestant Christianity that believes in the imminent Second Coming (or the "Second Advent") of Jesus Christ. It originated in the 1830s in the United States during the Second Great Awakening when Baptist preacher Willi ...
. It is considered
halal ''Halal'' (; ) is an Arabic word that translates to in English. Although the term ''halal'' is often associated with Islamic dietary laws, particularly meat that is slaughtered according to Islamic guidelines, it also governs ethical practices ...
according to Muslim dietary standards, because kangaroos are herbivorous.


See also

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References


Further reading

* * * *


External links


Video of Kangaroo giving Birth
{{Authority control Australian Aboriginal culture Macropods Marsupials of Australia National symbols of Australia Clawed herbivores Mammal common names Taxa named by John Edward Gray Paraphyletic groups