We were asked about eaglet growth and development during our explore.org Bird Week chat yesterday. Bald eagles spend about the first half of nest life – say, 35 to 40 days – gaining weight, growing limbs and feet, and growing and replacing feathers. In stage two – about 40 to 75 or 80 days – they begin preparing for life beyond the nest by building muscle, exploring their new wings, learning to unzip prey and feed themselves, and practicing their