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
KOA (AM) 1927, increased to 12,500 watts. KOA became an NBC affiliate in 1929, and the network took over operation of the station from GE shortly thereafter. On July 7, 1934, power was raised to the current level of 50,000 watts. In 1941, NBC, which had been operating the KOA and KGO in San Francisco for GE since October 1, 1929, also took over ownership of the stations. NBC continued to own KOA until June 1953 when it sold the station to Metropolitan Television Company, whose principal stockholder was Bob Hope. GE repurchased the station in 1968 and continued to own it