That would be tricky since it would be over the US border. You would need to get the proper permits and health certificates to allow your duck into the States, then secure a flight for your duck where it can be in a crate down in the cargo area with food and water in the crate. There are strict rules on importing animals into the US, and also for shipping them (can only be done at certain times of year when there are no extreme temperatures at either end of the trip, etc). We did this often with ducks and geese when I worked as a Zookeeper in the US (we shipped to other zoos), so it CAN be done, but must be done properly. Much more difficult for international travel, though.
It is not humane or legal to ship animals like a regular package, that is only done in the US with day-old chicks and ducklings since they can survive for a few days after hatch without eating. That is not ok with adult animals though, they must be booked on a flight as cargo with as short of a flight time as possible.
