How common are such cases, and how serious are they usually ?

A few weeks ago on a A330 on LH we got hit by birds just before takeoff in FRA. The plane must have been very close to take off speed, and we were pretty close to the end of the runaway when the plane came to stop.

Apparently a bird hat hit the left engine, which made a frightening noise. Fire engines showed up immediately and doused the engine with water, but the pilot said that no fire warning had come on. After maybe twenty minutes the plane rolled back to a parking position with only the right engine in operation, we left the plane through normal stairs and got bussed back to the terminal. The pilot confirmed that the engine was damaged and that we would have to wait for a replacement plane.

After all it was nothing too serious, but I can imagine that a birdstrike 3 seconds later, either when takeoff can not be aborted anymore, or at 100ft altitude can be more annoying.

I looked through the databases of the BFU and the NTSB, but found little reports about birdstrike (except the fatal crash of a Learjet in Milan earlier this year caused by a flock of birds after takeoff). Maybe 4 or 5 years ago I saw a severly damaged nose on a LH 737 in MAD, which was caused by birdstrike according to the station manager.

Surely there must be more incidents involving birds, or are they generally not reported?