Why do crows sit at the very top of a tree?

Once upon a time there was such a puzzle for children:

Why do birds sit on the tops of trees? Because they can't go higher.

Seen from a different point of view, however, these high bird stands are simply observation points. However, it should be remembered that, for example, in summer, birds do not choose such places due to the fact that they are exposed to rain, wind and predators. The places to stay overnight, however, must be high. It also has to do with hygiene, because, as you know, birds tend to pass droppings 'under themselves'. Therefore, they prefer not to be under someone else and choose the highest possible positions. You can often see that there are even scuffles between birds on tall branches. Here, however, the hierarchy plays a major role.