From a University of Missouri media release:
Many birds feed on mosquitoes that spread the West Nile virus, a disease that killed 286 people in the United States in 2012 according to the Centers for Disease Control. Birds also eat insects that can be agricultural pests. However, rising temperatures threaten wild birds, including the Missouri-native Acadian flycatcher, by making snakes more active, according to University of Missouri biologist John Faaborg. He noted that farmers, public health officials and wildlife managers should be aware of complex indirect effects of climate change in addition to the more obvious influences of higher temperatures and irregular weather patterns.
“A warmer climate may be causing snakes to become more active and seek more baby birds for food,” said Faaborg, professor of biological sciences in MU’s College of Arts and Science. “Although our study used 20 years of data from Missouri, similar threats to bird populations may occur around the world. Increased snake predation on birds is an example of an indirect consequence that forecasts of the effects of climate change often do not take into account.”