One of the earlier species to come back through are the palm warblers. The reason that they are one of the first back is because they do not winter as far south as most warblers. They typically winter in the southern U.S and Caribbean, while most species of warblers head down to Central and South America for the winter. Palms breed in northern Canada. They are found mostly in the eastern half of North America. I often hear palm warblers before I see them. Instead of flitting around in the trees like most warblers they are usually foraging through the leaf litter, like a fox sparrow, looking for insects and seeds.