Help? Depressed duck

[|Aphrodite|]

I had two ducks that grew up together along with all my chickens, and I accidentally left the coop door open one night. That night one of the ducks went missing, and the one left has gotten depressed. I don’t know if he eats or drinks because I leave before I get to see, but he’s very distant and always in a corner. I Heard that ducks can die of sadness (not sure if it’s true) but I’m very scared for his health, if anyone knows how to help him please tell me, I don’t want to loose another flock member.

 

[BoyTheRooster]

Maybe get him another duck for company? They're social animals, and I don't think chicken friends will cut it if he seems down