Sacred trees create wildlife islands: how indigenous beliefs preserve borneo’s forests

In the rainforests of Indonesian Borneo, ancient spiritual beliefs are proving to be powerful allies in conservation. The Indigenous Iban people of Sungai Utik have long believed that massive strangler fig trees house dangerous spirits capable of harming those who disturb them. These aren’t abstract beliefs—they’re rooted in vivid community stories, like that of a young boy who mysteriously vanished near a rice field, only to be found hours later beside a towering fig tree, claiming spirits had called to him and hidden him from searchers.

What makes this folklore remarkable is its measurable environmental impact. When the Iban clear land for farming, they carefully preserve these sacred fig trees along with protective buffers of surrounding forest. This practice, called “dipulau” (meaning “island”), creates scattered patches of vegetation throughout their agricultural landscape. Though these forest islands occupy only 1-2% of cultivated land, recent fieldwork reveals their outsized ecological importance.

Different strangler fig species fruit throughout the year, providing critical food sources for birds, primates, and wild pigs when other resources become scarce. Wildlife uses these living stepping stones to move safely between larger forest areas and farmland, maintaining crucial ecological connections that might otherwise be severed by agriculture.

This research, originally reported by Mongabay’s Liz Kimbrough, demonstrates how Indigenous spiritual practices can serve as effective conservation tools, protecting biodiversity through reverence rather than regulation. The sacred groves of Sungai Utik offer a compelling example of how traditional knowledge and environmental stewardship can work hand in hand.