Almost every part of the hummingbird’s life is shaped by their dependence on flowering plants. This includes their size, shape, their ability to hover in flight, their mating habits, and migration. The nectar that is found in flowers that has been pollinated by hummingbirds is very rich in sugars, especially sucrose, which is commonly found in sugar cane and sugar beets.The hummingbirds depend on these sources because of their high metabolic rates which are necessary for them to achieve hovering flight. The small body size of the hummingbird that helps them to achieve optimum flight performance, but it also results in a higher rate of heat loss. The hummingbird must take in an enormous about of calories to help ensure their ability to maintain a normal body temperature.
When it comes to selecting a food source, the color of a plant is far less important in determining a bird’s "favorite" nectar source. What is most important is the quantity and quality of the nectar which is available. Whenever choosing a flower, the hummingbird will select the flower with the highest nectar output and the richest concentration of sugars, regardless of the shape or color of the flower. Also more important than the color of the flower is how the nectar taste.