Humming For Warmth

One of the hummingbirds who visit our feeders.

Why is it that as soon as the hummingbirds return, the temperatures drop and the sun disappears?
These mornings are so cold, I wonder how the poor wee things are keeping warm. 
I once plucked a stiff body from a feeder after he froze while eating. That was heartbreaking. They are so small, so strong. Such survivors of everything -- but a cold Maritime morning.
We watched one drop off a feeder onto the ground one cold evening in May. Our old dog, Stella, rushed to "save" it and I do think she intended to by holding it in her mouth where it is warm. I convinced her that a vented ice cream container lined with a tea towel was a little more appropriate.
A hummingbird is a symbol of enjoyment of life and a lightness of being. Also of resilience and adaptability.