Oh Cyn, so sorry to hear Zane is so depressed. Sometimes it takes a while and a lot of love. Like I said, my Fussy grieved for two whole months when lil Fandango, the crossbeak died. They were inseparable at the time, would absolutely scream for each other if out of each other's sight. And then she was traumatized by just seeing me pick up lil Dango's body, to her it must have looked like I swooped up from above and took her away. She is skittish about me doing ANYTHING above her to this day. It took her two whole months to hold her tail feathers upright again, she would just slink around, with her tail slumped down. It was a horrid sight. The only thing kept her going was that she was slightly bonded with Red at the time, otherwise I am pretty sure I would have lost her too.
If Zane doesnt have any other buddy, its a double whammy. I think he is gonna need a lotsa babying. Sometimes if you cry WITH him, they can feel that, and I think it helped with my girl. She somehow picked up on the fact that I was hurting about it too and I think the shared grief helped her along. Not sure it would help with Zane, but you might have to talk to him and explain things, send lil mental images to him like you are trying telepathy. I have NO idea if they get thru, but it sure doesnt hurt to try.
I know thats hard for people to believe, that a chicken can grieve for two whole months, but my poor girl sure did, and its terribly worrisome to see.
Hugs to you and to Zane.
Jill