Researchers from the University of California Los Angeles and other universities recently reported that millions of birds have died because of West Nile virus.
This is a much higher rate of deaths among birds than scientists originally thought.
Out of the 49 species of birds included in the study, approximately half of them had drastically decreased survival rates in areas that have West Nile virus exposure. Original estimates suggest that one-third of the birds were in danger from the virus. This updated figure shows that birds are the species most affected by the virus.
“We looked at bird populations in the years before and after West Nile arrived in their habitats, and after the disease arrived you have this massive drop-off in so many of these species,” Ryan Harrigan, a co-first author on the paper and researcher with UCLA’s Center for Tropical Research and Institute of the Environment and Sustainability, said. “Seeing these massive effects in species with large, healthy populations is really alarming for smaller populations, which can’t rebound like a large population can.”
The study demonstrated that millions of birds die in just one year when they are exposed to the virus.
“These populations are getting hammered — over five years, they’re losing a third of their population,” Harrigan said. “They’re getting infected every year. In some species, this has gone on five or six years after the disease hit, so the idea that the populations have not recovered since then is a bit scary.”
