Diseases are moving up mountains faster than Hawaiian birds can escape

Hawaiian honeycreepers have already moved up mountains once. When mosquitos carrying unfamiliar diseases such as avian pox and malaria were introduced in the 1800s, the birds that weren’t wiped out escaped to high-altitude refuges, where it was too cold for the insects to survive.

Now as the climate warms, mosquitos are again on their tail, and this time, there is nowhere left for them to move, reports a U.S. Geological Survey study in the Journal of Avian Medicine and Surgery.

Rising temperatures will allow both mosquitos and the avian pathogens to survive at higher elevations. But because the birds are living at the tree line, above which forests don’t grow, they are up against the limits of their habitat. The results could be disastrous for the group of birds, which already include 14 endangered species. If temperatures rise 2 degrees Celsius, 60 to 96 percent of their disease-free refuge habitat could disappear.

The authors say that better forest management, especially at mid-elevations where most disease transmission occurs, will become increasingly urgent because it is only a matter of time before the birds can’t fly any higher. – Jessica Leber http://journalwatch.conservationmagazine.org

Source: Atkinson, C.T. et al. 2009. Introduced Avian Diseases, Climate Change, and the Future of Hawaiian Honeycreepers. Journal of Avian Medicine and Surgery DOI: 10.1647/2008-059.1