More than likely it is the water mover that has him scared. You need to turn the device on for at lease twice a day for approximately 30-45 minutes so that he can get used to it and see that it will not cause him any harm.

His skittishness may also have something to do with the
person(s) that was installing the device. Did he/she swat at the swan or cause any disturbance that might have caused him to be scared?

Just ensure that there are no hoses, cables, wires etc. that he can become entangled if he starts to snoop around as he could seriously hurt his legs or feet. If you can, turn the device on without him seeing you, let it run for about 30 minutes and then show up with the food. Eventually, he will get used to the new noise and water flow and will be back to his old self. Yes, if it is freezing cold and he has no other food resources, he will show up to you (the food bucket)!

Just make sure you run the device several times during the day for a little while so that he gets used to it before it turns cold and then it freaks him out so that he does possibly get out of the pond. The Regal Swan