Winter is hard on the urban wildlife. The swans are build in such a practical way that they can switch to the slow burner, and live on the internal storage for up to 6 weeks. That of course also means there is no energy to spare for chasing or fighting for food. You must aim the food directly at them, and if it does not land on the beak, it is dismissed.
Feeding the water birds in Copenhagen is not for the timid. Really it is a two man job. One to keep the seagulls from pulling a Hitchkock on you, and the other to power feed the ducks and the swans. The seagulls will attack any bird with food, including each other. The trick is to throw a strategic lump of bread as far as you can, and let them fight it out. The distraction will buy you maybe a full minute to feed the more peaceful ducks and swans, before mayhem returns. A two man team would be able to repeat as necessary, but if you are alone... you get the close encounter. Real close.
Today I found a relatively peaceful spot, the swans had a good feeding.
Begging at the table. If you are not up to speed, you get the hissing sound.