Doona Series by Anne McCaffrey, Jody Lynn Nye

The first humans to arrive on the beautiful, unspoiled planet of Doona drew up an intricate cohabitation contract with the alien, cat-like Hrrubans, who had settled there first. Now, after 25 years, the contract is due for renewal. Anne McCaffrey is a past winner of both the Hugo and Nebula awards.

The peace between humans and cat-like aliens on the unspoiled planet Doona has been hard won. Now a new race of aliens arrives, bringing with them promises of new technology and trade. But the devastating accusation that these newcomers once destroyed life on another planet puts the residents of Doona in peril.