Add Yahoo as a preferred source to see more of our stories on Google. Hummingbird migrations take place in spring and fall and those events are cause for excitement among many people. "They are the ...

Small but speedy. Tiny but aggressive. Little bodies, big appetites. Hummingbirds are a study in extremes. They are the lightest North American birds. Most weigh less than two pennies at 3 to 4 grams.

Small but speedy. Tiny but aggressive. Little bodies, big appetites. Hummingbirds are a study in extremes. They are the lightest North American birds. Most weigh less than two pennies at 3 to 4 grams.