The ruby-throated hummingbirds are already high profile in our gardens, flitting from flower to flower and then hovering in mid-flight before moving on to pollinate another blossom. Their favorite food plants are bright red to match their ruby-colored throat, including the red trumpet vine, red buckeye, morning glory, cardinal flower, and jewelweed.
In order to attract them to your own garden, hummingbird feeders must imitate a bright similar color of sweet-tasting liquid nectar, frequently refreshed and washed clean. The reward of a gathering is one of the most colorful avian behavior spectacles in your own backyards (see illustration).
If you should go out your back door to appreciate the gathering, they become very irritated by visitors, and true to their name to buzz around and dive bomb your head, as well as any other hummingbirds that are competing for feeding stations.
The ruby-throated hummingbirds are also considered to be polygamous because both males and females have multiple mates and do not establish as a breeding pair. After a short mating dance of aerial copulation, the female provides all the parental care from that time forward. She selects the nest site, usually near the tip of a down sloping branch in a fairly open area below a leafy canopy.
After laying several eggs, they are incubated between 10 to 14 days, and after hatching and rearing her first clutch, the ruby-throated hummingbird will later in the summer raise two or three additional families – every year.
With the progression of shorter days to find food late in the season, cooling temperatures necessitate that they must soon double their body mass before, like the monarch butterfly, beginning their autumn migration of at least 7,000 miles to winter in Mexico or Costa Rica. They make the whole trip at low levels over treetops and often non-stop over vast bodies of water, just above the waves and out of the wind.
Each leg of their passage must be timed to coordinate and coincide with the availability of food-plant energy to relay the ability to move on to the next region. They know how to communicate in this effort using tactile and visual signals to perceive in advance the favorability of sustenance ahead.
Somehow, they always seem to be ahead of the isotherm (average nightly freezing temperature). And they can see ahead the blue-violet content of the flowering flora advantageous to complete their destination of the annual life cycle for the next generation. Somehow the ruby-throated hummingbird has managed to accomplish an unbroken chain of environmental passage to ensure survival of this amazing species.
By George B. Emmons