What is a Kaenguru taxonomy

kangaroo is a redirect to this article. Further meanings are listed under Kangaroo (disambiguation).
Tree kangaroos, with their almost equally long front and rear legs, differ significantly from the blueprint of the other kangaroo species

The Kangaroos (Macropodidae; v. Greekmakrós μακρός 'large' and poús πούς, Gen. podós ποδός ‚foot‘) - as a distinction to the rat kangaroos also as Real or Actual kangaroos - are a family of the marsupial order Diprotodontia. They are among the most famous marsupials and typical representatives of the Australian fauna, but they also live in New Guinea. Kangaroos are characterized by their mostly clearly elongated hind legs and are herbivores that are mainly crepuscular or nocturnal. The family includes around 65 recent species, four of which are already extinct.

features

General physique

Kangaroos differ significantly in their dimensions. While the largest species, the red giant kangaroo, can reach a height of 1.8 meters and a weight of 90 kilograms, the shaggy rabbit kangaroo weighs only 0.8 to 1.8 kilograms and has a head body length of 31 to 39 centimeters .[1] In almost all species the hind legs are significantly longer and stronger than the front legs; Exceptions are the tree kangaroos, which have adapted to life in the trees and are no longer hopping around, and whose rear and front legs are approximately the same length. The tail is long, muscular and mostly hairy, it is often used as a support or balance, but cannot be used as a prehensile tail. The nail kangaroos have a bony tip. The fur is mostly colored in gray or brown tones, there are also patterned species, for example the rock kangaroos.

The front paws are small and end in five fingers; they are used for food intake and for support. The rear foot is narrow and elongated, kangaroos are sole walkers (plantigrad). The first toe of the hind feet is missing, the second and third toes have grown together as in all Diprotodontia, but end in two separate nails that are used for grooming. The fourth toe is the longest and strongest, the fifth is medium in size.

Head and teeth

The head is elongated and relatively small compared to the body size, the ears are large. In the upper jaw, kangaroos have a total of six incisors, in the lower jaw only two. As with all Diprotodontia, the lower incisors are enlarged and hit a hard point on the palate behind the upper ones when biting. The upper incisors are arranged in a U or V shape and are not one behind the other as in other Diprotodontia. This arrangement forms an effective tool for plucking even hard plant materials and is also found in convergent form in some cloven-hoofed animals. The lower canine teeth are missing, the upper ones are also missing or are severely receded, so that a large gap (diastema) separates the incisors and the molars. The premolars are narrow and blade-shaped, the molars are broad and high-crowned. The molars do not come out of the gums at the same time, but one after the other; only when the front ones are worn out and fail do the next ones come and then move forward in the mouth. Overall, the kangaroo's tooth formula is I3 / 1, C0-1 / 0, P 2/2, M4 / 4 - so they have a total of 32 or 34 teeth.

Internal anatomy and reproductive tract

The stomach of the kangaroo has developed like that of the ruminant with multiple chambers. It has three sections: the first section, the forestomach sac, serves as a fermentation chamber, where, similar to the rumen plant food, the food is processed with the help of microorganisms. Further digestion takes place in the tubular forestomach tube and in the posterior stomach.[2] As with most herbivores, the intestine is long and the appendix is ​​well developed. The cardiovascular system shows no special features compared to other marsupials. The reproductive tract also largely corresponds to that of the other marsupials. The penis of the male lies drawn in at rest and bent in an S-shape in a penis pocket, the testicles lie in front of the penis. Females have two uteri and two vaginas. In contrast to many other marsupials, the females have a permanent pouch (Marsupium). Its opening protrudes forward and it contains four teats. Male kangaroos do not have a pouch.

distribution and habitat

Rock kangaroos are one of the genus of kangaroo that inhabit rocky terrain

Kangaroos are found in Australia including offshore islands such as Tasmania and New Guinea. They inhabit different habitats and can be found in rainforests as well as in bush or grasslands and dry steppe and desert regions. Some species such as the rock and bush kangaroos also inhabit mountainous regions and can be found at altitudes of over 3,100 meters.

Way of life

Activity times and social behavior

The kangaroos are also variable in terms of activity times and social behavior. Most species are crepuscular or nocturnal, but to varying degrees they can also be observed during the day, for example when sunbathing in the afternoon. They spend the day in the shade of trees, in caves or crevices and in other shelters. These animals do not develop any pronounced social structures; sometimes loose associations of several individuals form, but these are not permanent.

Locomotion

When moving slowly, kangaroos use all four limbs and the tail

Depending on the speed requirement, many species of kangaroo have two types of locomotion: At higher speeds they only jump with their hind legs, the tail stays in the air and serves for balance. In this way they can briefly reach a speed of 50 km / h. In the larger species these sentences are often 9 meters long, in a gray giant kangaroo they are 13.5 meters long.[3] These jumps are hardly higher than 1.5 meters.

When walking slowly, kangaroos use “five limbs”: while the animal is supported with front paws and tail, the hind legs swing forward; as soon as these stand, the front paws and tail are brought up again. Hopping is very efficient at high speed. Thanks to special, highly elastic muscle ligaments, they can move forward quickly without spending a lot of energy, which is an advantage in a dry climate and sometimes poor food supply. At low speed, however, this sequence of movements is rather inefficient and energy-consuming. Kangaroos cannot move backwards.

The tree kangaroos do not hop, but they can climb well. The short-tailed quokkas and filanders move mainly on all fours.

food

Kangaroos are herbivores that feed on a wide variety of plants depending on their habitat. In simplified terms, a distinction can be made between grass-eating (e.g. red and gray giant kangaroos) and more leaf-eating (e.g. tree kangaroos) representatives, which also differ significantly in the shape of their molars. To varying degrees, they also consume other parts of the plant such as fruits, buds and other things. Thanks to their efficient digestive tract, they can make good use of the difficult-to-digest plant food, and some species also chew again. These adaptations - combined with the ability to get by with little water - mean that they can survive even in dry areas with little vegetation.

Reproduction

As with all marsupials, kangaroo babies are born relatively underdeveloped compared to placental animals after a short gestation period of around 20 to 40 days. Even with the largest kangaroo species, the red giant kangaroo, the young animal measures only 2.5 centimeters at birth and weighs 0.75 grams.[4] Usually only a single young is born, twins are rare. After giving birth, it crawls independently from the birth canal into the pouch and hangs by its mouth on a teat that it will not let go of for the next two to three months.

In many species there is a "delayed birth": Immediately after the birth of a young animal, the female mates again. However, this embryo hardly continues to grow until the large young animal has finally left the pouch. Only then does it develop further and is born. The evolutionary advantage is likely to be found in the sometimes inhospitable habitats of these animals: if the young animal dies or the mother has to leave it, a successor is there immediately.

The young animal leaves the pouch for the first time after about six months; at around eight months it has finally become too big to fit in. However, young animals are suckled up to the age of around one year, for this purpose they put their heads in the mother's pouch, where often another small young animal is already being fed. In such cases, large and small young animals drink from different teats, which also give milk in different compositions.

In Australia the young of most species of marsupials are called "joeys".

Kangaroos and people

etymology

The name kangaroo (English: kangaroo) comes from the language of the Aboriginal tribe of the Guugu Yimidhirr who live on the Cape York Peninsula. It is derived from the word "gangurru" (resp. gang-oo-roo), which is used as the name for a gray giant kangaroo.[5][6] The tribe has several words for the different species of kangaroo. According to a widespread story, the British navigator James Cook would have been the first European to sight these animals, and the name kangaroo means "I don't understand" in this Aboriginal language and is intended to answer the British question, "What kind of animal is that?" have been replied. That this story does not correspond to the facts was discovered in the 1970s by the linguist John B. Haviland during his research with the Guugu Yimidhirr.[7][8]

According to old German spelling, the correct spelling was Kangaroo. This was changed in the course of the 1996 spelling reform, since then kangaroo correctly.[9]

use

Kangaroos were already an important prey animal for the Aborigines, they hunted them for their meat (kangaroo meat) and also processed their skin. On the other hand, the slash and burn operated by the Aborigines, be it for hunting or, more recently, for simple agriculture, created new living space. The juxtaposition of burned-down areas, areas with young green and densely overgrown areas offered the animals food and refuge.

The Europeans also hunted these animals after their arrival. Today most of the Australian kangaroo species are protected. However, the red and gray giant kangaroos, which have spread significantly since the arrival of the Europeans and have no natural enemies, are hunted - unlike many other commercially used animals, there are no breeding farms. The shooting is subject to strict quotas; Every year around 3 million animals are shot in Australia.[10]

Kangaroo meat had a bad reputation for a long time; it was considered poor people's food only for those who could not afford anything else. In Australia itself, the meat is not very popular and is processed into animal feed,[11] a large part is exported - 80% to Europe.[12] Leather is also produced from the hunted kangaroos. Kangaroo leather is considered to be very tear-resistant due to the even alignment of the collagen fibers[13] and is used, among other things, to produce gloves, shoes and boots.

threat

A greater threat than hunting - which only affected the larger species - was and is for the kangaroos the destruction of their habitat. The Aboriginal concept of slash and burn was abandoned in favor of extensive pasture and agriculture, which severely restricted the habitat of many species. The reenactment by imported robbers like the red fox plays a further role.

Depending on their habitat and behavior, the species reacted differently to the changed living conditions. Four species (two species of rabbit kangaroo, the moon nail kangaroo and the eastern Irmawallaby) are extinct. Other species only inhabit a fraction of their previous habitat, so the banded rabbit kangaroo only lives on two small islands off the coast of Western Australia. There are also less threatened species: The rock kangaroos live mainly in mountainous regions that are unusable as animal pastures, so they do not have to fear any threat from this direction. The giant kangaroos are also widespread and not endangered.

The species in New Guinea were not exposed to the colonization of their habitat by the Europeans, but today they too suffer from the deforestation of the forests and the associated loss of their habitat. According to the IUCN, several species of tree and bush kangaroos on this island are considered threatened.

Cultural references

Sydney rock engraving style kangaroos

In the myths of the Aboriginal dreamtime there is a "big kangaroo". It made the animal people (the animal people) held back the water when the great flood came. After that, it spits out all the words that people on earth speak. It thus became the creator of all tones, sounds and languages.[14]

A kangaroo and an emu are the heraldic animals of Australia. Both animals can only move forward, which represents progress. In addition, kangaroos are ubiquitous as symbolic animals in Australia, for example on the emblem of the Qantas Airways airline or on the Australian one-dollar coin.

Systematics

External systematics and history of development

Within the marsupial mammals, kangaroos belong to the order Diprotodontia and within this group to the subordination of the Macropodiformes or Macropodoidea. In addition to the actual kangaroos, this subordination also includes the rat kangaroos (Potoroidae) and the primeval musk rat kangaroo, which is in its own family, Hypsiprymnodontidae. It is likely that the kangaroos evolved from tree-dwelling animals that resembled the musk rat kangaroo. This animal has a number of peculiarities that are no longer found in other species: it is very small, has approximately the same fore and hind limbs and a bare tail. The sister group of the kangaroos are the rat kangaroos, the parentage relationships within the Macropodiformes are expressed in the following cladogram:[15]

Macropodiformes ("kangaroo-like")
N.N.

Rat kangaroos (Potoroidae)


     

(Actual) kangaroos (Macropodidae)



     

Musk rat kangaroo (Hypsiprymnodontidae)



Within the kangaroos, the subfamily of the short-snouted kangaroos (Sthenurinae) first appeared in the Miocene, but reached their greatest diversity in the Pleistocene. It was generally characterized by a firmer build than today's species. In this subfamily evolved with the genus Procoptodon the largest kangaroos. The banded rabbit kangaroo used to be the only representative of the Sthenurinae still alive today. In the meantime, however, it is placed in the subfamily of the Lagostophinae[16]. The Sthenurinae have therefore been extinct since the late Pleistocene. The remaining recent species all belong to the Macropodinae subfamily, which has also been documented since the Miocene.

In the Pleistocene, around 51,000 to 38,000 years ago, there was a mass extinction of larger animals in Australia, including some giant kangaroos (Procoptodon, Simosthenurus) other groups of marsupials such as the diprotodonts and the marsupial lions were also affected. This extinction has worldwide parallels; the time of this Quaternary extinction wave roughly correlates with the history of human settlement. It is unclear to what extent human hunting (overkill hypothesis) or climatic factors are responsible - due to the binding of large amounts of water during the Würm Ice Age, severe drought prevailed. A mixture of the two causes is also conceivable: the animal world, which was affected by the climatic changes, could no longer withstand the hunting pressure that began with the arrival of humans.[17]

Inner systematics - the recent genera

The quokka is the only representative of the genus Setonix

Within the kangaroos there are eleven genera with a total of 65 recent species; 4 of these species are already considered extinct:[18]

  • The banded rabbit kangaroo (Lagostrophus fasciatus) is the most primitive living representative of the kangaroos and is classified in its own subfamily, Lagostrophinae.
  • The bush kangaroos (6 species in the two genera Dorcopsis and Dorcopsulus) are rainforest inhabitants of New Guinea.
  • The tree kangaroos (genus Dendrolagus) are tree-dwelling animals in New Guinea and on the Australian Cape York Peninsula. There are 12 types.
  • The rock kangaroos (Petrogale) are medium-sized, often patterned animals that live in mountainous countries in Australia. The genus includes 16 species.
  • The filanders are characterized by a barely hairy tail. The 7 species of this genus live in Australia and New Guinea.
  • The rabbit kangaroos (Lagorchestes) got their name because they are reminiscent of rabbits in terms of size and locomotion. Of the four species, two are already extinct.
  • The quokka or short-tailed kangaroo (Setonix brachyurus) is characterized by the short ears and the short tail.
  • The nail kangaroos (Onychogalea) have a bony nail at the end of their tail. The genus includes two living and one extinct species.
  • The swamp wallaby (Wallabia bicolor) is a small species from Southeast Australia.
  • The genus Macropus comprises 14 species, which can be divided into three sub-genera:
    • The subgenus of wallabies (Notamacropus) counts 8 species, including one extinct.
    • The subgenus of the gray kangaroos (Macropus) is composed of two types.
    • The subgenus Osphranter consists of the three species of mountain kangaroo and the red giant kangaroo, the largest living kangaroo species.

The genealogical relationships of the genera to one another are shown in the following diagram. This was developed by Marcel Cadillo and others in 2004 using a combination of many different phylogenetic studies.[15]

Kangaroos (Macropodidae)
Macropodinae
Bush kangaroos

 Dorcopsis


     

 Dorcopsulus



N.N.

 Dendrolagus (Tree kangaroos)


N.N.
N.N.

 Lagorchestes (Rabbit kangaroos)


N.N.

 Setonix (Quokka)


N.N.

 Onychogalea (Nail kangaroos)


N.N.

 Macropus (Giant kangaroos, mountain kangaroos and wallabies)


     

 Wallabia (Swamp wallaby)






N.N.

 Petrogale (Rock kangaroos)


     

 Thylogale (Filander)






     

 Lagostrophus (Banded rabbit kangaroo)



literature

  • Terence J. Dawson: Kangaroos. Cornell University Press, Comstock, Cornell 1995, ISBN 0-8014-8262-3
  • Tim Flannery: Mammals of New Guinea. Cornell University Press, Cornell 1995, ISBN 0-8014-3149-2
  • Udo Gansloßer (Ed.): The kangaroos. Filander, Fürth 1999, 2004, ISBN 3-930831-30-9
  • Bernhard Grzimek: Grzimek's animal life. Volume 10. Mammals 1. Droemer-Knauer, Munich, DTV, Munich, Bechtermünz, Augsburg 1979, 2000, ISBN 3-8289-1603-1, pp. 128-164
  • John A. Long, inter alia: Prehistoric Mammals of Australia and New Guinea. Johns Hopkins University Press, Baltimore 2003, ISBN 0-8018-7223-5
  • Ronald Strahan: Mammals of Australia. Smithsonian Books, Washington DC 1996, ISBN 1-56098-673-5
  • Ronald M. Nowak: Walker's Mammals of the World. 6th edition. Johns Hopkins University Press, Baltimore 1999, ISBN 0-8018-5789-9.

Individual evidence

  1. ↑ Figures from Walker (1999), pp. 115 and 119.
  2. ↑ Ulrich Zeller: Marsupialia (Metatheria, Didelphia), marsupials. In: Wilfried Westheide and Reinhard Rieger (Eds.): Special Zoology Part 2: Vertebrate or Skull Animals, Gustav Fischer Verlag, Stuttgart Jena & New York 2003, ISBN 3-8274-0900-4, pp. 491-492,
  3. ↑ Nowak (1999), p. 120.
  4. ↑ Animal Diversity Web: Macropus rufus
  5. ↑ Tony Horwitz: Cook - The discovery of an explorer. Piper, Munich 2006, pp. 271f. ISBN 3-492-24473-4
  6. ↑ Douglas Harper, Historian (December 22, 2009): kangaroo. In: Online Etymology Dictionary. Dictionary.com.
  7. ↑ John B. Haviland: A last look at Cook's Guugu-Yimidhirr wordlist. In Oceania. 44 (3), 1974, pp. 216-232 PDF - see pp.216 (note 1) and 229
  8. kangaroo. In: The American Heritage® Dictionary of the English Language, Fourth Edition. Houghton Mifflin Company (2004). Retrieved December 22, 2009.
  9. ↑ Duden: Kangaroo
  10. ↑ An industry that's under the gun: Report of the Sydney Morning Herald of September 26, 2007
  11. ↑ Exotics on the menu, accessed on May 10, 2009.
  12. ↑ Kangaroo meat boom on BBC News March 16, 2001
  13. ↑ Information from KIAA (Kangaroo Industry Association of Australia)
  14. ↑ R. Lewis: The Beginner's Guide to Australian Aboriginal Art. The symbols, their meanings and some Dreamtime stories. 3rd edition 2004, Fountainhead Press, Canning Vale DC, ISBN 0-646-40368-0.
  15. 15,015,1M. Cardillo, O. R. P. Bininda-Emonds, E. Boakes, A. Purvis: A species-level phylogenetic supertree of marsupials. in: Journal of Zoology. London 264.2004 (PDF). ISSN 0268-196X
  16. ↑ Prideaux, G. J. and Warburton, N. M. (2010), 'An osteology-based appraisal of the phylogeny and evolution of kangaroos and wallabies (Macropodidae: Marsupialia)', Zoological Journal of the Linnean Society, 159 (4), 954-87. http://dx.doi.org/10.1111/j.1096-3642.2009.00607.x
  17. ↑ T. S. Kemp: The Origin & Evolution of Mammals. Oxford University Press, Oxford 2005, ISBN 0-19-850761-5, pp. 288-290.
  18. ↑ after Don E. Wilson, DeeAnn M. Reeder (Ed.): Mammal Species of the World. A Taxonomic and Geographic Reference. 3. Edition. Johns Hopkins University Press, Baltimore 2005, ISBN 0-8018-8221-4.

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