Should savanna be capitalized in a sentence if not at the beginning?

No, "savanna" is not capitalized unless it is at the beginning of a sentence or part of a proper noun.

Examples:

* Correct: The savanna is home to many animals.

* Correct: We went on safari in the Serengeti savanna.

* Incorrect: The Savanna is home to many animals.

"Savanna" is a common noun, referring to a type of grassland ecosystem. It's similar to words like "forest," "desert," or "mountain" which are not capitalized unless they are part of a proper noun.