The mass die-off of thousands of songbirds in south-western US was caused by long-term starvation, made worse by unseasonably cold weather probably linked to the climate crisis, scientists have said.
https://www.theguardian.com/environment/2020/dec/26/mass-die-off-of-birds-in-south-western-us-caused-by-starvation-aoe
https://www.theguardian.com/environment/2020/dec/26/mass-die-off-of-birds-in-south-western-us-caused-by-starvation-aoe