How has a deer adapted its habitat?
Deer have adapted to be able to run very fast and jump high. They also eat at night, when there are fewer humans around.
The deer "industry", if it can exist, is probably quite sustainable. Over the years, deer have adapted to have more offspring to compensate for the encroachment upon their natural habitat by humans. This is a problem because in breeding is starting to occur, however, contrary to popular belief, killing them will not solve this problem. What they need is more habitat.