Birds inside a bird cage don't die properly

I observed in my world that when a bird in a birdcage starves, it dies like a bird that would starve in e.g. a player's inventory, i.e.

• it drops either a morsel or a feather, next to the cage and not on its "shelf"
• the birdcage state isn't set to the death state but simply back to empty state
• the birdcage won't have a bird corpse inside and can't be mucked out

It sounds to me like the OnBirdStarve function is never called.