Pulau Maratua, Pulau Kakaban and Pulau Nunukan are part of the Derawan Islands off the coast of East Kalimantan. Most of these islands are atolls originally formed by volcanic action. The volcanoes slowly sank as coral reefs grew around the old rim, resulting in the formation of shallow lagoons and saline lakes connected to the sea by underground passages. The Derawan islands are separated from mainland Borneo by a 200 m deep sea trench and were never connected to mainland Borneo during the low sea levels of the ice ages. The result is a unique fauna and flora with several endemic birds and plants found nowhere else in the world.
This is a rare Grey Imperial Pigeon Ducula pickeringii an important disperser of the rare figs that grow on the Derawan Islands of East Kalimantan.