Shorter days in mid to late summer trigger the hummer's natural urge to head south. After all, less sun means colder temperatures and fewer flowers and insects to eat. (A bird doesn't know that. It just wants to eat and go!) A pre-migration feeding frenzy finds it fighting furiously for food. Even mothers and their young become rivals! It gets even more intense as hungry hummers from up north pass through in August and September.

Click for a larger photo, and look closely! One young male is yanking on the
other one's tail. Fueling up for a long journey south is serious business!

Photo: Russ Thompson