The Little Hen and the Great War by Jennifer Beck (author) and Robyn Belton (illustrator) (UK edition)

A young soldier is fighting in the trenches of wartime France when he finds a hen, skinny, scruffy, and starving. He tucks her into his jacket and takes her with him. The other soldiers laugh when they see him looking after her and sharing his meagre rations of food, but when the hen thrives and begins to lay eggs for them, they realise that perhaps survival and hope are possible after all. A beautiful story of unexpected friendship in the midst of fighting and devastation.