I seem to remember from school that the beak recognition is not very good, either. Just any big yellow thing would do - don't know about the seagull specifically, though. Also, they don't recognize if the beak is attached to a seagull or something else.
http://news.ycombinator.com/item?id=410778
The article explains the level of image recognition that is available to seagulls from birth (i.e., genetically.) Basically, you can trick them into thinking beak-like objects are actually their mother's beak.
As for the question at hand, we have to ask what happens to a male who never sees any breasts before adulthood. Will he still find them attractive?