The Kangaroo Question
Why do some species of animals only live in one specific part of the world? There are different factors that influence the answer to this question.
One of the reasons some species cannot live in other areas of the world is because of climate. Some animals live in hot areas and a more temperate climate would not be suitable for their constitution. There are species that need dry areas to live in, others might prefer humid areas, some might want heating weather, others freezing weather. The climate also affects physical factors in which the individual is made and accustomed to live in. The pH of the soil could be more acidic and not fit the preferences of a species or there could be lots of forest fires in some times of the year that the species could not be able to support. Some species might also rather having less salinity in the land or receive a lot more sunlight. All these type of factors are classified as abiotic factors, for they are not alive.
There also exists living or biotic factors that contribute to the inability of a species to live in other areas of the world. Biotic factors include parasites and pathogens that could sicken and end up wiping out the species in the land. There is also the problem of predators, incorrect vegetation, and competitors that use the same resources to survive. All these could extinguish a species or make it really difficult for it to reproduce and become numerous in a specific area, ultimately making it impossible for it to inhabit in that place.
The movement of a certain species of animals to another place could also be obstructed by geographical barriers. A Kangaroo living in Australia doesn’t also live in California because it can’t swim through the ocean. Imagining it could swim through the ocean, the Kangaroo would have to climb some mountains to get to a suitable habitat and then find a mate to reproduce.
Finally, some species might just not want the suitable habitat. Their behavior could most likely reject it. For example, the European Corn Borer Larvae only places its eggs in corn to feed when they are born. When they want to reproduce, the larvae look for mates in the corn. This behavioral pattern of the Corn Borer does not allow it inhabit in other bunch of habitats that would suit it perfectly.
All these factors are reasons why some animals only live in certain parts of the world when they could live in many others as well.