The Yellow Island offshoots

[Prompt: A culture that has suffered under the rule of a stronger nation]
Early in skitter history, before power and norms and knowledge had fully coalesced, there was a plurality who went off to make their own nation. For whatever reason, these people were unsatisfied by the way the main body of the group was heading. They had other ideas for governance, and the itch for new grounds. So they set out, and found another island to call home.
Generations later, the two skitter groups are still of one species, but they have handily diverged. The inhabitants of Yellow Island have adapted to their strangely sandy home, gaining traits the larger nation has yet to see. The Yellows are far less conquer-happy, though, and have kept largely to their home, content to develop and create peacefully.
Beneficial genes, plus a disposition against defense: this is a recipe for tragedy and exploitation.
Such happens precisely. As the colonies master the art of bridge-building, they link to every island they can find, eventually, inevitably making their way to their wayward cousins. As soon as they see the desert-adapted skitters (a family of fennec foxes and kangaroo rats), they know they must have those genes for their own. And so they kidnap.
Mayhem rules the moment the colonies choose violence. Of course, the more-native skitters fight back, but their desperate flailing is no match for the colonists' disciplined training. Bodies are ripped from their families, and those left on the island are put under surveillance and control. New ways are forced upon them, as is the way of dominators.
I don't yet know how this story ends. I have a tragically adorable tale for the beginning of it, in which one Yellow Islander falls in love with a pair of explorers. Their intentions were best, but even the greatest love can't stop every atrocity. Later colonists are not so wholesome, and those on Yellow Island know better than to trust.