Few years back, early evening I saw more [UK] magpies congregated in one place than ever before in my life.
Can't remember how many, at least 6 or 7, they were spaced out over a few roofs & chimneys in the centre of town.
There were also a smaller number of black crows, maybe 2 or 3.

I can't remember now if they were still and quiet, or making a commotion ?

Whatever, It was surprising even a bit weird seeing so many all together.

When I returned about 2 hours later, one of the black crows was laid out on the pavement dead ???