Invasive species in Hawaii and health-related problems. The introduction of mosquitoes to Hawaii has resulted in the spread of avian malaria, and increases the risk of dengue and west Nile virus (not known to be in Hawaii yet). Other native species can be affected by invasive species diseases as well, such as the once-dominant koa tree being killed by koa wilt, which is believed to have been brought into Hawaii on an ornamental acacia plant, and the 'ohi'a tree, now being affected by Rapid Ohia Death. Invasive predators can severely reduce the population sizes of native species, or even drive them extinct, because native
ʻAnianiau Its call is a pair of notes, "tew-weet", while its song is a trill of "wee-see, wee-see, wee-see". Anianiau are found in mesic and wet forests at elevations above . The highest densities occur above . Dominant tree species in its habitat include koa ("Acacia koa"), ōhia lehua ("Metrosideros polymorpha"), ōlapa ("Cheirodendron trigynum"), and lapalapa ("C. platyphyllum"). The anianiau mainly feeds on nectar from the flowers of plants such as ōhia lehua ("Metrosideros polymorpha"), ōhelo ("Vaccinium" spp.), and alani ("Melicope" spp.). It will also take arthropods from trees, shrubs, or vines. The anianiau breeding season ranges from February to June.