Dead birds from Austin to Australia- what the heck?

"AUSTIN, Texas — Police shut down 10 blocks in downtown Austin for several hours Monday after 63 birds were found dead in the street, but officials said preliminary tests found no threat to people." LINK

"Mystery as thousands of dead birds fall from sky
Is it an illness, toxins or a natural phenomenon? A string of autopsies in Perth have shed no light on the mystery.
All the residents of flood-devastated Esperance know is that their "dawn chorus" of singing birds is missing.
...She told The Australian she normally had hundreds of birds in her yard, but that she and a neighbour counted 80 dead birds in one day.
"It went to the point where we had nothing, not a bird," she said.
"It was like a moonscape, just horrible. But the frightening thing for us, we didn't find any more birds after that. We literally didn't have any birds left to die."
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