The eagle has the longest lifespan of birds at up to 50 years. However, as eagles reach their twenties their talons become less flexible for grabbing prey and their beaks become bent. Their heavy, thick feathers also make flying difficult. The only options are to die or undergo a painful 60 day process of renewal. The eagle flies to a mountain top, knocks its beak against a rock to remove it, and waits for a new beak to grow. It then removes its talons and molts its old feathers, emerging after 5 months to live another 30 years. This process allows the eagle to shed old burdens and take advantage of more time.