“Kira-kira” in Indonesian translates to estimating or predicting. In the Inanwatan Regency of Southwest Papua, Indonesia, mangrove trees are commonly used to estimate the optimal time for fishing or harvesting crabs.
For generations, coastal communities have relied on mangrove trees, particularly the Xylocarpus granatum species, which is prevalent along the coasts of Africa, Australasia, the Pacific Islands, and Asia, including Indonesia.
Mangroves flourish in various regions of Indonesia, such as Borneo, Maluku, Sumba, and Papua, leading to diverse local names like banang-bang, nyiri, siri, nilyh, nyirih bunga, nyuru, jombok ivory, buli, black buli, inggili, nipa, niumeri, kara, mokmof, kabau, or niri.
The Inanwatan District in Southwest Papua boasts a thriving Xylocarpus granatum ecosystem, referred to by its inhabitants as the Kira-kira tree, signifying a tree aiding in prediction or estimation in the Indonesian language.
Morphologically, the leaves are pinnated or feather-like, appearing on both sides of the same axis. Their color transitions from pale green to yellowish/dark with age. The changing color pattern of mangrove leaves is used by the Inanwatan residents to predict the optimal time for fish and crab harvesting.
Locals understand that darkening leaves signal the time for fish and crabs to lay eggs. During this period, they abstain from coastal harvesting, awaiting the return of pale green leaves, indicating the hatching of eggs and the readiness for harvest. This method of estimating the reproduction cycle of fish and crabs has persisted in the collective memory of the Inanwatan people for centuries.
Kira-kira tree flourish in Inanwatan waters.
The Kira-kira tree also offers various economic benefits. Growing up to 10-20 meters tall, it produces robust wood suitable for boat building, house construction, furniture, and tool handles. Tannin extracted from the bark strengthens ropes and serves as a natural dye. Additionally, the bark, fruit, and seeds are used in traditional medicine.
The fruit of the Kira-kira tree resembles a coconut, weighing 1-2 kilograms when ripe, with a rough, brownish-green surface, earning it the nickname “cannonball mangrove tree.” When dried, the fruit’s skin cracks, revealing irregularly shaped fruits that fit together like a puzzle. Consequently, the fruit has earned the moniker “puzzle fruit,” as people often shake the seeds and attempt to reassemble them like a puzzle game.
The numerous names for mangroves reflect the deep connection between the ecosystem and the traditions and life of the Inanwatan people. From an ethnoecological perspective, a branch of science examining the relationship between communities and ecosystems, the Inanwatan people have adapted to coexist harmoniously with their natural environment, challenging the assumption that human adaptation only involves conquering or exploiting nature.
While the International Union for Conservation of Nature (IUCN red list) categorizes Kira-kira trees as “least concern,” the tree population in Papua is dwindling due to extensive land use changes caused by industrial-scale land conversion. Urgent conservation efforts, guided by the local wisdom of Papuans who intimately understand the mangrove ecosystem, are essential to preserve it.
