In Justine McKeen, Walk the Talk, the second book in the Justine McKeen series, Justine decides there are too many cars idling in front of her school. So she comes up with a solution that should help keep the air cleaner. But she soon discovers not many adults trust her crazy ideas.
Maxine loves her giant tree in the Walbran Valley, but as she gazes at clearcuts from the car window, she worries. What if her tree is gone? Her family and friends trek through the old growth forest, and Maxine runs on ahead to check. Yes, her tree is there. She stands at its foot and listens, but it doesn't make its special sound, "Keer, keer." She will soon learn that "Keer, keer" is the sound a marbled murrelet (a mamu) makes. The mamu is an endangered seabird that flies far from the sea to nest in the high flat branches of the Sitka spruce. When a tree-climber confirms the presence of a mamu nest, Maxine's tree will be safe forever.