Hawaii’s forest birds are facing a growing threat from avian malaria, a new study in Nature Communications reveals. Almost all bird species in the state are now spreading this disease, which highlights the challenges of managing wildlife in this popular tourist destination.
The research, conducted by scientists from the University of Hawaii at Manoa and the University of California, involved analyzing blood samples from over 4,000 birds across 64 locations. They also carried out feeding trials where mosquitoes were fed infected birds to observe how different temperatures affected disease transmission.
Interestingly, both native and non-native forest bird species can infect mosquitoes when consumed, meaning that even birds with low levels of the parasite can transmit the disease for long periods, sometimes months or years.
Krista M. Seidl, a researcher involved in the study, emphasized the severity of avian malaria’s impact on Hawaii’s native birds. She noted that the silent infections in various bird species make controlling the situation difficult. This underscores the need for effective mosquito management to protect these vulnerable populations.
Unlike many other ecosystems where diseases might circulate through a few species, this study found avian malaria to be widespread among many types of birds. The introduction of non-native mosquitoes poses an additional risk to the survival of Hawaii’s forest birds. For example, the akikiki bird, once found in the wild on Kauai, is now considered extinct.
According to the National Audubon Society, while avian malaria is not transmissible to humans, it does belong to the same family as the malaria parasite affecting people. Although it doesn’t directly kill birds, it can affect DNA elements, such as telomeres, leading to shorter lifespans. This genetic damage can also pass on to the next generation, further compounding the issue.
The researchers acknowledged some limitations in their study. They primarily used canaries in controlled environments, which might not reflect wild bird behaviors accurately. Additionally, measuring how much malaria-carrying saliva mosquitoes produce at various temperatures posed a challenge. Their model attempts to address this, but some uncertainty remains. Moreover, they had to rely on infection patterns to infer mosquito feeding preferences since tracking every mosquito bite in the wild is impractical.
