The ākohekohe currently survives only on Maui, but also lived on the eastern side of the island of
Molokai until 1907. This bird was common on both islands at the start of the 20th century. It was thought to be extinct after that—however, in 1945 a small population was discovered in the National Area Reserve on Haleakalā in Maui. Over the course of the millennia, the population has decreased. The first human settlement of Hawaii by
Polynesians led to considerable habitat loss and ecological changes such as deforestation for human settlements and agriculture, particularly in lowland areas. The Polynesian rat (
Rattus exulans) was also introduced to the islands at this time, which was a significant component of habitat loss and species decline. When
Europeans arrived, the land and habitat loss and extinctions accelerated. Europeans brought with them two additional species of
rats, which predated eggs, chicks, and adults of many bird species, and introduced ungulates which caused further deforestation. Another factor that lead to the decline of the ākohekohe was its unusual appearance, which made it desirable to collectors. In the mid-1800s, mosquitoes were introduced to the Hawaiian Islands, and later, mosquito-transmitted diseases such as avian malaria and avian pox. Mosquitoes, particularly
Culex quinquefasciatus, are vectors for these diseases. Hawaiian honeycreepers such as
Palmeria dolei lack natural resistance to these pathogens and because of this avian malaria has a high mortality rate among Hawaiian honeycreepers. Humans also released
invasive birds which compete with
native birds for resources, and can also operate as vectors for avian malaria and other diseases to which they are resistant. == Conservation ==