Hummingbirds are captivating garden visitors. Many associate these tiny birds with the color red, often noticing red feeders or liquid inside them. This raises questions about red’s significance in hummingbird feeding and the safety of adding color to their food.
How Hummingbirds See Colors
Hummingbirds possess a unique visual system, perceiving colors beyond human sight. Unlike humans with three color-sensing cone cells, birds, including hummingbirds, have a fourth cone type. This additional cone enables them to detect ultraviolet (UV) light, giving them tetrachromatic vision.
Their enhanced color perception plays a significant role in their foraging behavior. In natural environments, hummingbirds are highly attracted to red and orange flowers, which often signal a rich source of nectar. This innate preference and learned association with high-quality nectar makes red a powerful attractant. Hummingbirds instinctively investigate red objects, including flowers and feeders, as potential food sources.
The Debate Over Red Dyes
Adding red dye to hummingbird food stemmed from the belief that nectar needed to be red to attract them. However, natural flower nectar is clear; the attraction to red is for the feeder’s appearance, not the liquid. Despite its widespread use in commercial nectars, scientific evidence does not support its necessity or safety.
Red Dye #40, a common petroleum-based artificial coloring, is banned in several European countries due to safety concerns, though approved in the U.S. No scientific studies definitively prove red dye is safe for hummingbirds. Evidence from wildlife rehabilitators suggests potential harm, including increased mortality and tumors.
A hummingbird consuming dyed nectar could ingest Red Dye #40 concentrations up to 17 times the human daily intake, and 12 times amounts shown to induce DNA damage in mice. The dye can also linger in their system for over 24 hours.
Preparing Safe Nectar
Preparing safe hummingbird nectar at home involves only two ingredients: white granulated sugar and water. The recommended ratio is one part sugar to four parts water; for example, mix one cup of sugar with four cups of water until the sugar is fully dissolved. Boiling the water can help remove impurities and extend the nectar’s freshness, especially in warmer climates.
Do not add red dye to homemade nectar; red feeder elements are sufficient to attract hummingbirds. Extra sugar water can be stored in the refrigerator for up to two weeks. Clean feeders regularly to prevent mold and bacterial growth, ideally every other day in hot weather, and at least twice a week in cooler conditions. Use hot water and a brush, avoiding soap or harsh chemicals.