Skinny Hummers?
As hummingbirds prepare for migration they stuff themselves with insects and spiders. Fat layers build on the hummingbird's back, belly, and throat. This fat, and the amount of food they can find along the way, sustains them through their migration and helps to keep them alive during cold spells. When you observe your first hummingbird, take note of the condition of the bird. Report your observations.