pigeons, plural

Two days ago, i was in the apartment when i noticed a strange cooing from our balcony.  By strange, i mean both a different pattern of vocalizations than what Burt (our Cuban racing pigeon) usually makes, & also a different pigeon voice.  Upon investigation, i discover a much larger, darker pigeon chasing our much smaller grey pigeon around the balcony.  I sat, quietly watching the scene, uncertain of what to do.  Noticing that this new pigeon is without tags, i decided to put our tennis rackets to use, shooing the wild bird away.

The next day, the same thing happens again.  Same cooing, same shooing.

This evening, Roomie & I sat outside, thrilled by the sight of two baby dolphins in the canal, when we noticed a sudden swooping of feathers around the building.  It was Burt, alternatively pursuing & being pursued by the black pigeon.  Curious, we watched, until Roomie finally suggested, 'What if Burt is actually a lady bird?  A sexy lady bird?"  Of course, neither of us know the answer to that question, but it has now posed the new question of what to do regarding this new visitor? (And, given the amount of poop one pigeon produces, this visitor is one we aren't hoping to encourage.)