Male has dark headed
crown and a Ruby Red Throat Breakfast
frenzy
Females have no dark crown
or throat feathers
Typically, they are territorial, fight over feeders, hummer wars
throughout the day, except for sharing the first morning feeding when
hunger keeps them too busy.
Another interesting fact - hummers lower their body temp at night and
enter a torpor to conserve energy. Takes about an hour for them to warm
up in the morning.