'native population' is completely correct and usable in written English.
Example sentence: The native population of the country has seen a dramatic increase since last year.
(In the jargon of the CIA, the native population was designated as NEGL: negligible).
(Urban Natives constitute more than half of the over-all U.S. Native population).
Welch had witnessed the 1918-19 flu pandemic that killed half the native population of Nome.
It can work if you are a native population ceding countryside to an invader.
He believed the native population was in danger of being swamped by an alien culture.
The native population makes up about 4% of Canada's population though it remains among the poorest.
Here nomadic populations entered from the north to mingle with the native population.
Venice's vanishing native population should be a cautionary tale to many cities, including New York.
The native population understood the continent in ways the settlers, colonialists, farmers and miners never have.
That gesture of conciliation toward the native population was good politics.
Fleming, I. A. et al. Lifetime success and interactions of farm salmon invading a native population.
