f; earlier looked like it was weakening
y; probably it ran out of food
f; what happens then?
y; it will go back home
f; i see

This was part of the commentary when they were showing the bird fighting with the character. I presume from this that you have to keep feeding the bird during the fight if it's a long one, or perhaps some kind of energy level which needs to
be reached before the fight starts then maintained.
It would have been interesting if they had expanded on this a little.