What are the causes of wildlife extinction?

Well presently it's people! The actual physical cause is that their habitat is no longer suitable. They can no longer find food, a safe place to breed or rest, they become polluted and diseased, the place becomes too hot, too cold, too wet, too dry. In the past this was purely down to natural causes such as a comet hitting the Earth, kicking up dust which reduced the sunlight reaching Earth and caused global temperatures to drop (one theory for the mass extinction of dinosaurs). But now it is humans who are destroying animal's environments. Rainforests are one of the most diverse places on Earth with millions of species of plants and animals. We are chopping them down for cheap wood, to graze cattle for cheap meat for fast food chains and to grow palm oil which is used in masses of food and other products. So the orangutans are suspected to only have 5 years left! We pollute the seas, we cause global warming... the list goes on. And there are things we can all do. Check whether the products you buy contain palm oil. Help to reduce global warming. Use linen or hemp bags (many turtles, most of which are endangered, are killed when they swallow plastic bags that they mistake for jelly fish). You don't have to be a saint but there are little compromises you make that taken as a whole will make a difference. Most people are starting to change so there is hope yet!
The main cause is: HUMANS
Hello!

There is many possible answers to this. But, for certain, wildlife has one, deadly enemy. Humans. Humans are building houses and all kinds of factories where there was once beautiful fields and forests. They cut them down, pollute the air with greenhouse gases, ruining the earths atmosphere, polluting the Earth's rivers. Especially rivers like the Amazon. Causing Ebola. We humans are ruining wildlife, and if this keeps up, wildlife will become extinct.

Luckily, there are some people like Jane Godall (I can't spell her last name) who are helping wildlife. Please do the same. GO GREEN!!
Because we keep killing it, one way or another.