Adult female Ospreys begin their fall migration in August, before their young are completely independent. After females leave, males continue to feed this year’s young and don’t reach the peak of their migration until the middle of September. Ospreys tend to migrate during the day, except when crossing over large bodies of water, which they do at night. Unfortunately, the nocturnal flights of northeastern Ospreys over the Caribbean (a 25-hour nonstop flight) on their way to their wintering grounds in South America often coincides with the hurricane season. As treacherous as this is, 80 percent of adult Ospreys survive migration, according to the National Wildlife Federation.