Are there studies on how red dyes affect hummingbirds?
May 7, 2015
A recent visitor to the Field Guide to Hummingbirds Facebook page asked a question that comes up frequently in discussions of the use of petroleum-based food dyes in hummingbird feeder solutions:
Have any scientific studies been conducted to determine the effects of these chemicals on hummingbirds? Some people are surprised to learn that the answer is an emphatic "NO." Despite oft-repeated (and oft-debunked) urban legends that the San Diego Zoo, Audubon Society, or some other trustworthy source tested red dye on hummingbirds and found one or more specific effects (liver damage, kidney damage, cancer, tumors, "birth defects," weakened eggshells, or, in some versions of the story, no harm at all), there is no evidence that any such testing has ever been conducted on hummingbirds by anyone anywhere.