Extinction does not drive evolution, reproduction does, and if a species' food goes extinct, they reproduce less, not more.
Secondly, these animals aren't abandoning their niches, they're losing them due to human activities. There is no room for another species to adapt to it, because there is nothing there to adapt to anymore.
Secondly, these animals aren't abandoning their niches, they're losing them due to human activities. There is no room for another species to adapt to it, because there is nothing there to adapt to anymore.