Quail begins to grow pin-feathers at about 8 days of age. Before this stage, natal down predominates, and neonates are extremely vulnerable to the elements. Feathers play a crucial role in providing lift and propulsion for quail, particularly when they are flushing to avoid predators. This development is significant for the quail's ability to navigate their environment and escape potential threats, highlighting the importance of feathers in their early stages of life.