is a parasitic disease
is most notably caused by Plasmodium relictum
, a protist
that infects birds in tropical regions
. There are several other species
that infect birds, such as Plasmodium anasum
and Plasmodium gallinaceum
, but these are of less importance except, in occasional cases, for the poultry
industry. The disease is found worldwide, with important exceptions. Usually, it does not kill birds. However, in areas where avian malaria is newly introduced, such as the islands of Hawaii, it can be devastating to birds that have lost resistance over evolutionary time.
Its main vector
in Hawaii is the mosquito Culex quinquefasciatus
, which was introduced
to the Hawaiian islands
in 1826. Since then, avian malaria and avian pox together have devastated the native bird population, resulting in many extinctions. Hawaii has more extinct birds than anywhere else in the world; just since the 1980s, 10 unique birds have disappeared.
Virtually every individual of endemic
species below 4000 feet in elevation has been eliminated by the disease. These mosquitoes are limited to lower elevations, below 5,000 feet, by cold temperatures that prevent larval development. However, they appear to be slowly gaining a foothold at higher elevations and their range may be expanding upwards. If so, most remaining Hawaiian land birds may become at risk to extinction.
Most of the Hawaii islands have a maximum elevation of less... Read More