Old Man in the Roughworks

During the day, at the west edge of the Roughworks, there is an NPC. Part of his dialogue seems to suggest you can give him seeds to feed the birds, but I don't know what kind. I tried the seeds that are part of

Spoiler: Secret Discovery

Hidden In Plain Sight

but it didn't work. I tried Assorted Seeds (the crafting ingredient) but that didn't work either. If anyone knows what item you're supposed to give him, please share.

 

None of the four RW SDs involve that guy. I don't know what his deal is.