Related? Flying over meth labs?
Dozens of yellow-headed blackbirds mysteriously drop dead in Mexico
https://nypost.com/2022/02/12/dozens-of-yellow-headed-blackbirds-mysteriously-drop-dead-in-mexico/
The video is rather horrifying
It looks like those birds flew through high voltage power lines, and were so many so close together that they formed a path to ground and were electrocuted.