Come to think of it...
If an Ocampa can only have one baby, why doesn't the population of Ocampa cut in half every five years?
Multiple births, twins or triplets, and a higher female to male ratio, which would suggest polygamy.
This is the debt that can never be repaid.
Genocide. Every generation is shrinking by half, because of something caretaker did, so that one day in the future he could fuck off after the Ocampa as a species had had a "good" run.