Large transport flight crew report bird strike departing CLT. After noting change in engine pitch and sight increase in vibration; crew elects to return. Evidence of bird strike is found on post flight.

Narrative

Upon takeoff from CLT Runway 36R at approximately 50 FT AGL; we noticed at least 2 birds in our departure path. The birds appeared to be white seagulls. Just as we flew past the birds; we heard a slight change in the sound of one of the engines; the sound appeared to be changed on the right side of the aircraft. No impact was felt and no smell of bird was noticed in the air conditioning. We continued climbout and did not notice any abnormal engine indications or loss of thrust; however; the higher pitched sound from the right engine continued throughout climbout. Approaching leveloff; we noticed a higher than normal vibration indication on the #2 engine. It fluctuated with power changes but never was high enough to trigger an amber or red indication. After consulting with Dispatch and Maintenance Control we elected to return to CLT rather than continue. Slight vibration fluctuations continued throughout the flight. All other engine indications remained normal. Remainder of flight was non-eventful and after an underweight landing in CLT on Runway 36C a postflight walkaround found indications of a bird strike in the #2 engine.