Testosterone o'clock

Poor young lads.
So full of it they even attempted a spot of parkour.
They soon realised that it wasn't quite as impressive as the videos they have seen on Youtube.
And it's sore for the knees.

So they walked up and down the pier howling, and laughing, and screeching, and hollering, and yodelling, and generally producing any sort of (loud) sound likely to attract the attention of a female on the mating path.

Another few years of waiting lads...

Possibly decades if you do not tone down the bouncing and yelling.