I agree with DGFone. It was shown in the movie and the books that the lion king protect the lands from dangers and other predators, searches for water and food source when it's drought and helps the animals if they have troubles and generaly keeps the safety and balance among the animals.
Simba asked the same question
[quote]Mufasa: Everything you see exists together, in a delicate
balance. As king, you need to understand that balance,
and respect all the creatures-- from the crawling ant
to the leaping antelope.
Simba: But, Dad, don't we eat the antelope?
Mufasa: Yes, Simba, but let me explain. When we die, our
bodies become the grass. And the antelope eat the
grass. And so we are all connected in the great Circle
of Life.[/quote]