What are the results when an animal habitat is lost?

You may have been too specific with this question...

There are an infinite amount of different ways in which habitats can be affected, so I'm just going to assume you mean "how are endangered species habitats generally affected by human influence".

The most important human affect on habitats would be habitat loss and destruction. As humans move into more remote areas and urban sprawl continues, vital animal habitat is inevitably destroyed. Also, we often harvest items from the forests that are actually important habitat to many animals, which can be seen as another form of habitat destruction. Fragmentation is another example of human affect: when we build roads, fences, etc.. through wildland areas, it fragments the habitat and can cause isolation of populations.