Raw, organic, turbinado and brown sugar are harmful to hummingbirds. You should only make your hummingbird nectar with granulated white sugar. Cane sugar is preferable, but beet sugar is also acceptable. Don’t use confectioner’s sugar either, as it contains an anti-caking agent.
Raw, turbinado and organic sugar is made by taking sugar cane and squeezing out the juice. The juice is then evaporated and spun in a turbine (hence the name “turbinado”) to produce the sugar crystals. These crystals are a golden color and are rich in vitamins and minerals. This is great for us, but not so great for the hummingbirds. One of the minerals these sugars contain is iron, and hummingbirds have very little tolerance for it. Brown sugar is white sugar that has had molasses added to it. Molasses is rich in iron. Agave nectar also contains iron.
Hummingbirds, being very tiny birds with fast metabolisms, must eat a lot of food to survive. Since they are so small, they are susceptible to excess dietary iron buildup in their system. The oversupply of iron is stored in the liver and is toxic to liver cells. So the refining process which was intended to make sugar white and more attractive has actually removed the iron, making it safer for hummingbirds.
In 2001 the birds in the Arizona-Sonora Desert Museum hummingbird aviary started dying off. Over a period of three months, 25 of 26 hummingbirds consisting of seven different species were dead. Necropsy of these birds revealed the presence of massive amounts of iron in their intestinal and liver cells.* These were essentially captive birds being fed a commercial nectar product that had too high iron levels, resulting in the birds developing iron toxicosis. Now every nectar product is tested for iron levels before being introduced to their current bird population.
Using honey to make hummingbird nectar might cause a different problem entirely. The general consensus is that a honey and water solution rapidly ferments and encourages the growth of a deadly bacterium and fungus. After much internet search, I could not find one study to support this. I also could not discover which “deadly” bacterium or fungus would grow in honey that would not grow in a sugar solution just as quickly on a hot day. This mantra has certainly been repeated enough, though. I cannot think of any reason why I would put honey in my hummingbird feeders, anyway. It’s too expensive and I would have no idea what proportions to mix. So until honey becomes much cheaper than cane sugar, I will not even think about why I should or shouldn’t do it!
Until next time,
Studio City, California
*Frederick, H., Dierenfeld, E., Irlbeck, N., and S. Dial. 2003. Analysis of nectar replacement products and a case of iron toxicosis in hummingbirds. In Ward, A., Brooks, M., Maslanka, M., Eds. Proceedings of the Fifth Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Minneapolis, MN