Avian malaria affects wild birds worldwide

A type of malaria that is not harmful to humans is killing birds across the globe. Now, new research looks at how and why avian malaria is spreading so rapidly.

“Avian malaria now affects somewhere between 13 and 14 percent – on average – of all wild birds worldwide. It’s caused by a group of blood parasites – known as haemosporidian parasites – and, much like human malaria, is transmitted via blood-feeding insects like mosquitos,” said study lead author Dr. Konstans Wells.

“It can’t harm humans but is known to have significant impacts on bird populations. For example, when avian malaria was introduced into Hawaii in the late 1800s to early 1900s, it was one of the major causes of extinction of about one-third of the 55 known species of Hawaiian honeycreepers. We’ve found that there are hotspots transmitting these parasites across the world.”

The scientists analyzed data from 53,000 wild bird examinations. This data was then combined with remote environment sensing technology to show what factors seem to be risk factors for malaria. 

“Since each bird species is unique in its ecological niche and is differently exposed to disease-transmitting insects during breeding and migration, infection risks are not the same for different bird species,” said Dr. Wells.

“Conditions that enable infection in different areas across the world are completely context-dependent. For example, long distance migrating birds were more likely to be infected in some continents but less likely in others.”

Although there is still much to learn, the data shows that there are hotspots of avian malaria transmission throughout the world. With more data needed, the scientists plan to continue their research to hopefully find a way to assist birds with this deadly parasite. 

“There’s no easy answer with so many factors at play, but we’re going to continue our research to find out how to best protect the world’s bird species from this deadly disease and better understand the spillover from harmful parasite from one species to another,” said Dr. Wells.

The study is published in the journal Global Ecology and Biogeography.

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By Zach Fitzner, Earth.com Staff Writer