Hummingbirds are high-energy pollinators that require a constant supply of food to fuel their rapid metabolism and hovering flight. They must locate hundreds of nectar-rich flowers daily, relying heavily on their senses to find the most rewarding food sources quickly. For these birds, the primary sensory input guiding them to a meal is the bright visual signal of color, as their sense of smell is poor. Understanding how they perceive and prioritize these colors offers a direct look into their survival strategy.
The Dominant Attractor Colors
Hummingbirds show a strong, consistent attraction to objects and flowers colored red and orange. These colors, which exist on the longer-wavelength end of the visible light spectrum, are reliable indicators of the food they seek. Following closely behind red and orange, bright pinks also prove highly attractive. This preference is deeply rooted in evolutionary history, where these colors often mark tubular flowers that contain copious amounts of nectar.
The preference for red and red-adjacent colors is also thought to be a mechanism for avoiding competition. Many insects, such as bees, do not see the longer-wavelength red color as well as birds do, meaning they are less attracted to red flowers. This leaves the nectar-rich resource largely available to the hummingbird. The color acts as a flag, but the concentration of nectar is the ultimate reward, with red flowers often having a high sugar content.
Understanding Hummingbird Vision
The reason hummingbirds are so tuned to certain colors lies in their specialized visual anatomy. Unlike humans, who have three types of color-sensitive cones in their eyes (trichromatic vision), hummingbirds possess four types of cones, giving them what is known as tetrachromatic vision. This additional cone allows them to detect ultraviolet (UV) light, extending their visible spectrum far beyond what a human can perceive.
This advanced color perception means hummingbirds see flower colors in a fundamentally different way than we do. Their ability to see UV light allows them to perceive “non-spectral” colors, which are combinations of UV and visible light that do not appear in the rainbow. Hummingbirds can distinguish between combinations like ultraviolet-plus-green and ultraviolet-plus-red. This sophisticated visual system helps them differentiate between flowers that look similar to the human eye, enabling them to quickly identify and return to plants offering the best nectar quality. This visual acuity allows for highly efficient foraging, which is necessary to sustain their high metabolic rate.
Practical Application in Feeders and Gardens
The strong attraction to red should be leveraged when using artificial feeders, but with certain precautions. Choosing a feeder with red ports, bases, or a red reservoir is highly effective in attracting the birds, as the color of the object is the primary visual cue. However, the liquid nectar placed inside the feeder should always be a simple, clear solution of plain white granulated sugar and water, typically in a four-to-one ratio.
Adding red dye or food coloring to the sugar water is unnecessary and poses potential health risks. Commercial red dyes, such as Red Dye #40, are derived from petrochemicals. Studies suggest that a hummingbird consuming dyed nectar could ingest the chemical at levels significantly higher than the accepted daily intake recommended for humans. The red color of the feeder itself is sufficient to attract the birds, removing any need to color the food source.
In the garden, planting natural tubular flowers in shades of red, orange, and bright pink is the most sustainable way to support hummingbirds. Species such as trumpet vine, bee balm, and specific salvias are naturally adapted to hummingbird pollination and offer the high-quality nectar they require. Focus on planting a variety of these high-yield, warm-colored flowers to provide a safe and consistent food supply.