He made the boxes because he was lonely. He didn't have anyone to love, and he made the boxes so he could love them, and so people would know that he existed, and because birds are free and the boxes are hiding places for the birds so they will feel safe, and he wanted to be free and be safe. The boxes are for him so he can be a bird.
Audrey NiffeneggerEven her name seemed empty, as though it had detached itself from her and was floating untethered in his mind. How am I supposed to live without you? It was not a matter of the body; his body would carry on as usual. The problem was located in the word how: he would live, but without Elspeth the flavour, the manner, the method of living were lost to him. He would have to relearn solitude.
Audrey Niffenegger