A large animal needs a large ...

A large animal needs a large area. If you protect that area, you're also protecting thousands of other plants and animals. You're saving all these species that future generations will want - you're saving the world for your children and your children's children. . . . The destruction of species is final. If you lose a species, you lose the genes, you lose all the potential drugs and potential foods that could be useful to the next generations. The ecosystems will not function as they have.
 George Schaller

Quotes from the same author

Mountains and deserts, with their sparse life at the limit of existence, make one restless and disconsolate; one becomes an explorer in an intellectual realm as well as in a physical one.
 George Schaller