I hit a blackbird on final for White Waltham (can't remember the runway)where these things seemed to flock at the threshold. There was a thump as one of them hit the port undercarriage leg. Pulled off the runway and checked, everything was OK so I reported it and carried on with my circuits.
I would imagine that something cruising at 120-130 knots taking a blackbird / seagull sized bird on the windscreen would result in the pilot eating an avian sandwich. Don't forget that the windscreens are ony 1/4" of perspex.