Engine breather?

Just been for an ‘enthusiastic’ run on my 2002 EV. Oil seems to have leaked from a pipe between the engines and down over the starter motor.

Forgive my ignorance, but would this be from a breather? (I hope!)

it is either a breather OR the feed pipe to the rockers, not difficult to replace, or tighten up the union/jubilee clip.

Thank you. I will have at it tomorrow.