As Jake Pool scoops up a log for the new Eagle Passage habitat at Northwest Trek, he does it with more care than you’d usually use with a bulldozer. This is precious cargo – in many ways. First, it’s a centuries-old trunk, hand-picked in the Free-Roaming Area from where it was cast aside by loggers long ago. It has survived a fire, and now nurses dozens of tiny seedlings and ferns. But most importantly, it’s going to become, along with other logs, a ramp for rescued bald eagles – part of an exhibit designed to make a sustainable home for …