With all the other things we have to do in the spring, worrying about our hummingbird feeders is not on many people’s mind. The red dye that is in many commercial hummingbird nectars contains red dye #40. Red Dye #40 has proven carcinogenic and mutagenic (meaning that it induces tumors) in rats and mice. Further, it decreases reproduction rates and increases the incidence of both internal and skin tumors in these animals. It is banned in France, Germany, and several other countries but is still in use in the U.S.
Although there is no research for directly testing this dye on hummingbirds, there is also no research indicating it is not harmful. This dye is approved for human consumption but the FDA has set limits for consumption and recommends people not injest large quantities of a single dye product. The truth is that a hummingbird taking artificially dyed nectar may be ingesting the dye in concentrations that are 12 times higher than the concentration found to induce DNA damage in mice. To add to the problem, they may be injesting this high concentration all summer long.
The good news is, you can purchase hummingbird nectar that does not have a dye additive or,with a little effort, you can make your own. The red color is not necessary to attract the hummingbirds as your feeder probably has a red cap, base and floral decoration to attract them, but, if you feel the color is needed, you can use natural sources of red coloring such as cranberry or fruit punch to colorize the nectar. There are many receipes online, most calling for a 4 to one ratio of refined sugar to water you can use to fill your feeders. You will also want to keep your feeder clean and out of full direct sunlight to ensure there is less a chance of bacteria forming in the feeder.