Write short note: Uniqueness of fauna in the Notogean realm. 2013 UPSC Geography Optional Mains Question.
Austral Realm/ Notogean Realm
Evolution ; Biogeographical evolution is characterized by continental drifting and Orogenic changes
Drifting : Australia was having Mediterranean and temperate deciduous vegetation. As it started drifting by breaking away from Antarctica in the early Cenozoic period, it came under the influence of cold West wind drift current, increasing the aridity of Australia.
Orogeny : As it drifted further to the north and reached the sub-tropics, the orogeny of Great Dividing range started and its rain shadow effect converted a large part of Australia into desert from the temperate forest and Mediterranean vegetation .
The Xerophytic vegetation and arid climatic conditions restricted the growth of Mammal families in Australia.
Most of the mammals in Australia are believed to have come from outside via the Island bridges and settled there, undergone speciation, to attain the present form. All major mammals including Monotremes like Duck billed Platypus, Marsupials like Kangaroo, Bats, Rodents and several dog species were believed to be speciated forms of initial migrants, that came to the continent.
Faunal Characteristics
Mammals :
Marsupials like Kangaroo, Opossum etc and Monotremes (Echidnas and Platypus) are found instead of antelopes.
Koala is an arboreal herbivorous marsupial native to Australia.
Pigs are only found till the Oceania Islands, while smaller mammals like Bats and Rodents with more dispersal power are found in Australia.
Birds : Australia have large varieties of birds like Honeysuckers, Birds-of-paradise , Megapodes and Mound Builders like Emu.
Reptiles : Several varieties of lizards snakes and insects are also found in the continent. All major sea turtles like Hawksbill Turtle, Leatherback Turtle, Loggerhead Turtle and Olive Ridley Turtles are found in Australian waters.
Australian Turkey
Koala
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