The image streams over YouTube in crisp grayscale: a young cahow — known outside Bermuda as the Bermuda petrel — scrambles through a sandy tunnel and pokes its tiny head above the ground for the first time. It’s a few months old, but it has never seen daylight. Gray fluffball hatchlings spend their whole lives up to this moment in a pitch-dark burrow as far as 15 feet underground. Now, in the middle of the night, this little bird flaps and flexes its wings, perches at the edge of a…