Asia is a vast continent filled with many different habitats; all displaying their own peculiar characteristics to which the Asian animals have been forced to adapt. Since Asia has no natural biogeographic boundary to Europe, many Asian animals are also European animals. Asia has also been connected to North America through the Bering land bridge in the past.

The history of Asian animals
The Asian fauna contains elements from two different ancient supercontinents: Laurasia and Gondwana. The animals from Gondwana arrived to Asia when the Indian subcontinent split from Gondwana and ended up attached to Asia instead. As mentioned above, Asia has been connected to North America many times in the past which has made the mammal and bird fauna of Asia and North America quite similar. A majority of the species did however move from Asia to North America and not the other way around. Just like in Europe, north Asian animals have been forced to deal with repeated ice ages intermingled by warmer periods which have lead to the development of both cold tolerant and cold abhorring Asian animals. Colonization by man has also had an impact on the distribution of Asian fauna.

Asian animals today
In the northernmost parts of Asia you will find cold hardy animals like moose, gray wolf, wolverine, and Siberian roe deer. If you venture to Lake Baikal, the oldest and deepest lake on the planet, you will find numerous endemic animals, including the Baikal seal. The northernmost parts of Asia consists of the tundra of northern Russia and Scandinavia, a comparatively barren region which eventually gives room to the vast boreal coniferous forest known as the taiga. During the winter liquid water is hard to find, both on the tundra and in the taiga, and many Asian animals living here hibernate during the winter. Those who stay awake usually decrease their activity level considerably to save energy. South of the taiga you will find temperate broadleaf and mixed forests as well as temperate coniferous forests.  

Central Asia and the Iranian plateau are home to Asian animals adapted to life in arid steppe grasslands and desert basins, expect for the high mountains and plateaux where you will find forest animals. Deserts like the Gobi desert might seem relentless, but quite a few animals have still managed to adapt to this environment and you can for instance encounter Bactrian camels here. To the west you have the Caucasus Mountains running from the Black Sea to the Caspian Sea; mountains covered in a mix of coniferous, broadleaf, and mixed forests. The Caspian Sea, the Aral Sea and Lake Balkhash all have saline or brackish water and their own weird and wonderful fauna.

The famous belt of Middle-Eastern deserts is also a part of Asia and forms a boundary that few land animals can cross. The Asian animals living here have adapted to arid conditions and extreme temperatures. They are sensitive to habitat destruction and hunting and many species have become extinct due to human activities. Some species have however been successfully re-introduced to the region, e.g. the sand gazelle and the Arabian oryx.  

The Mediterranean Sea forms the boundary between Europe, Africa and Asia. East of the Mediterranean Sea you will find the Asian part of the Mediterranean basin ecoregion, a region heavily impacted by human activity on all three continents. Less than 5 percent of the region's original vegetation remains and numerous animals have become extinct, mainly because of habitat loss and hunting. This region is currently home to 13,000 endemic species.    

If we move to the south-east we reach the Himalaya and several other mountain ranges which together form the boundary between the Palearctic and Indomalaya ecoregions. The Indian subcontinent bioregion south of the Himalaya encompasses not only India but most of Pakistan, Bangladesh, Nepal, Bhutan, and Sri Lanka as well. In this environment you will find tropical and subtropical Asian animals, including two orders endemic to the Indomalayan ecoregion: the Colugos and the Treeshrews. You will also find iconic Asian mammals like the tiger, leopard, Asian elephant, Asian water buffalo, Indian rhinoceros and Javan rhinoceros.       

Another important animal boundary in Asia is Malesia, a province straddling the border between Indomalaya and Australasia. It contains the Malay Peninsula, Indonesia, and New Guinea, and is bisected by the so called Wallace Line. West of the Wallace Line you can expect to find more or less the same Asian land animals as you would on the nearby Asian mainland, but on the islands east of the line land animals generally hail from Australia and you can for instance encounter marsupial mammals here.

The richest part of the Indomalaya ecozone is Indochina; a bioregion encompassing most of mainland Southeast Asia including southern China. The region is home of about 500 known mammal species, but the number might increase as the region become more thoroughly explored. The Laotian rock rat was for instance described by science quite recently. This region is also famous for its rich bird diversity with roughly 1300 described species.