Watching Seagulls

Six of us (or as many as are in town) have done tai chi near the San Francisco Ferry Building for something like 20 years (with major renovations forcing us to move from place to place).  On the wharf where we have practiced for many years, we yearly watch two seagulls (I think it is the same male and female) become parents.  We see them copulate, then build a nest in the same corner of the wharf that runs parallel to ours.  We watch the seagull on her (his?) nest for weeks, then the birth of the little chicks.  One (the father?) keeps watch, chasing away seagulls wanting to harm the chicks; one (the mother?) upchucks food for them.  That abandoned pier provides a good runway for the young seagulls  when the start running with hopping leaps as they try their wings.  Last weekend, one rose on his wings  higher than the rail but it did not fly over and away (so long as the mother continues to feed it?)  I was there early, observing seagull behavior, and soon there were four men watching their behavior, and one of them shouted encouragement when one of the birds seemed as if he might take wing and fly away.