Hitting any bird can be nasty. Me mate, Linz had a wood pigeon smash into his head at about 140 a couple of years back. The thing just exploded off his head like a firework. I thought he was definately off when it hit him, but he stayed on and we all ended up laughing about it, but at the time it was a tad scary. Amusingly, my bike was covered in blood, guts and feathers, but another lad behind me got an airbox full of feathers, which cost him a bob or 2 to get sorted out.
