When migration time was getting close what changes started happening that told the birds it was time to go south or west in the book Frightful Mountain?

Are turkeys slow birds that lack the aility to fly? How long to babies sparrows stay in the nest? How does a duck know if there a duckling inside the egg? Is The Barred Owl An Enemy? How old are baby plovers before the parents stop swooping? How many babies does a dodo have? Are All types of penguins Endangered? When did the northern cardinal become Virginia's state bird? What are two types of birdfeeders? What other birds look like owls? Were do toucans live on the map? How long have the snowbirds been flying for? How do you fly in incredibots 2? Is the heron and the hummingbird fable? What is Kings Duck Solution? How long before a gegos eggs hatch? What is the Celtic word for raven? What is a chickpea in afrikaans? How do you say little hummingbird in mikmaq? Does a womens egg have to drop for here to get pregnant?