Birds eat just like the rest of us. They need nutrition in order to be able to live. With eating, they gain strength and that allows them to be able to fly and do daily tasks.
I think that the conflict that the lawyer faces is that during his solitary confinment, he has learnt that material goods are not the most important and that in the end, he does not care about the outcome of the debt.
Alternatively, in the early stages of his confinement he is struggling with loneliness, so he has to fight himself not to succumb to it.
This says "Noah's Ark by Lonel Teoreanu summary"
I hope this helps!! :)