Most weekdays mornings I am in the last carriage of a train bound for Dandenong ("City of Opportunity") on the notorious Pakenham Line. So when the train pulls into Caulfield station I invariably see from the carriage window a rather large quantity of pigeons perched on the three phase power lines immediately outside of the station. There is a definite preference for one particular stretch, with the overflow on the next stretch towards the station buildings.

Why do they like this particular spot to watch trains from? And, why do they all sit facing the same direction? are two obvious questions but there are others.

When the power engineers specify overhead wiring do they take in to consideration not only the maximum current loading of the wiring but the maximum potential weight of birds that could be sitting on the line?

When a new arrival lands and disturbs the wire, and the current residents compensate for the movement, does this ever result in the wire moving even more (what engineers call a positive feedback loop) and everybody having to leap off? I have never seen it happen.

Following on from that one: is there some formula involving wire weight, tension and the approach speed of your average weight pigeon that determines the effective carrying capacity of a stretch of wire?

How do weather conditions affect carrying capacity?
Presumably on a cold morning they like to snuggle up to each other and you get more pigeons per metre than on a warm sunny day. And a gusty day will have its own effects.

I assume that none of this actually troubles the pigeons themselves they are probably discussing other things:
"I see the Frankston train is 6 minutes late"
"No, that's the 7:48 to Dandenong"
"At platform 2?"
"The VLine to Traralgon is late and they are letting it through"