Oʻahu nukupuʻu bill to pluck insects found underneath tree bark, the Oahu nukupuu fed on insects on flowering trees such as the koa ("Acacia koa") and ohia ("Metrosideros polymorpha"). These trees attract a large amount of insects due to their nectar-filled flowers. The Oahu nukupuu fed on koa in high elevation forests and fed on ohia in low elevations. The species was believed to have vanished as the spread of disease occurred, killing off nukupuu populations across the islands. In order to control the rat population in the sugar cane fields, mongooses were introduced to Hawaii and were suspected to be predators
Acacia sensu lato fragrant timber used for ornaments. "A. seyal" is thought to be the shittah-tree of the Bible, which supplied shittim-wood. According to the Book of Exodus, this was used in the construction of the Ark of the Covenant. "A. koa" from the Hawaiian Islands and "A. heterophylla" from Réunion are both excellent timber trees. Depending on abundance and regional culture, some "Acacia" species (e.g. "A. fumosa") are traditionally used locally as firewoods. It is also used to make homes for different animals. In Indonesia (mainly in Sumatra) and in Malaysia (mainly in Sabah), plantations of "A. mangium" are being established to