Dozens of birds have been caught on camera dying in mid air and dropping to the ground.
The bizarre phenomena was spotted as the flock of swallows flew above buildings in Laibin, in the Guangxi region of China.
Eyewitnesses say the swallows flew around in circles before dropping from the sky.
Dozens of the birds were seen lying dead on the ground after apparently being unable to withstand the freezing temperatures.
Swallows are small to medium-sized birds known for their sleek, streamlined bodies and graceful flight. Species found in colder regions migrate during the winter when their insect prey populations collapse.
They typically have pointed wings, a forked tail, and often exhibit striking, iridescent plumage.
Swallows are highly agile in flight and many species are known for their distinctive aerial acrobatics.
These migratory birds are found on every continent except Antarctica and are often associated with nesting in colonies, and building cup-shaped nests in various locations, including cliffs, buildings, or other structures.
Species found in colder regions migrate during the winter when their insect prey populations collapse.
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