About a month ago I saw a female American redstart on the ground next to the brick walk in our heavily vegetated front yard in Miami. I reach down; it didn’t fly but scurried into the bushes. Later that day I found it dead near the walk.
Sounds like a window-strike. Sometimes I find dead birds on walks. First thing I do is look up. Power lines. Things fly in the dark and hit them, especially on ridges.