BOGOTÁ, Colombia — Colombia marked the first anniversary Sunday of the rescue of four Indigenous children who survived a small plane crash in the Amazon rainforest in an operation that gripped the world’s attention. A small ceremony was held in a Bogotá military base that included an emotional reunion between soldiers and Indigenous volunteers.

But the four children, who were found in a remote patch of rainforest a year ago after fending for themselves for 40 days, still face an…