With hummingbirds returning to their northern homes from their wintering grounds, it’s the perfect time for a short refresher course in the best (and worst) practices for feeding them. I’m assuming here that you already have a feeder you’re happy with, one that is easy to clean and refill and doesn’t attract bees. To fill it with a safe and effective substitute for flower nectar, you’ll need the following ingredients:
1. White sugar.
- Sucrose, a.k.a. white table sugar, is a natural sugar that is the most abundant sugar in both the sap of plants and the nectars of hummingbird-pollinated flowers (1). We get our sucrose by squeezing sugar cane and sugar beets, and hummingbirds get theirs by drinking nectar, sap, and properly made feeder solutions. It does not give them diabetes. It will not rot their teeth.
- Pure cane sugar is often recommended based on reports that the birds prefer it over pure beet or blended sugar (which is usually labeled simply as “sugar”). As yet there’s no hard evidence to support this.
- If ordinary granulated sugar doesn’t dissolve quickly enough for you, and you don’t mind trading cost for convenience, buy superfine baker’s or caster sugar instead (but not powdered sugar, which contains anti-caking agents).
2. Good-quality water.
- If you don’t personally drink water straight out of your home tap for any reason (too many minerals, funky taste or smell, tested positive for pollutants, etc.), don’t make your hummingbird guests drink it, either. If it’s cloudy or discolored by iron, you definitely shouldn’t use it to make feeder solution (see the second bullet point under the “don’ts” below).
- Researchers have determined that hummingbirds’ kidneys are incredibly good at getting rid of excess water with minimal loss of electrolyte salts (2), which clears the way for feeder solutions made with water purified by reverse osmosis or distillation. Water softened by ion exchange is high in sodium, and overloading the birds on sodium may not be a good idea.
Sugar. Water. That’s all you need. Really.
The Basic Recipe: 1 part sugar + 4 parts water
Though opinions about ratios of sugar to water vary slightly within the hummingbird community, most hummingbird experts endorse this recipe. Good old 1:4 (or 4:1) has proven itself safe and effective over more than four decades of use, it’s well within the range of sugar concentrations found in the nectar of hummingbird-pollinated flowers (1), and, like a one-size-fits-most garment, it leaves enough “wiggle room” to accommodate some challenging environmental conditions without short-changing the birds on either energy or water. Slightly stronger solutions (1:3) are helpful for migrating and wintering hummingbirds, and slightly weaker (up to 1:6) keeps them hydrated and cool in extreme summer heat, but all the average hummingbird host needs to remember is 1 part white sugar + 4 parts clean water.
Briefly boiling the solution on the stove top or in the microwave dissolves the sugar quickly and may delay spoilage by killing spores of yeasts, molds, bacteria, etc. in the sugar and/or water, but it isn’t strictly necessary. Sugar water spoils quickly no matter what you do, so clean and refill your feeders every three days in cool, mild weather and daily in very hot, windy, and/or rainy weather. My favorite cleaning method is to spray hydrogen peroxide on all feeder surfaces, let it soak for a couple of minutes, then brush and rinse to remove organic debris.
“Alternative” ingredients that don’t belong in hummingbird feeder solutions:
Artificial coloring. The petroleum-based dyes used in commercial food coloring and most “instant nectar” products are like nothing the birds would ever encounter in nature. These dyes may not be dangerous at human consumption levels, but hummingbirds can drink two to five times their weight in liquid in a day. Medical research has linked large dosages of these dyes to a number of serious health problems. Backyard comparisons also suggest that the birds don’t like the way these dyes taste. If colorless sugar water just doesn’t look right to you, tint it with a teaspoon of natural tart cherry or raspberry juice concentrate (available online and from health food stores) and clean your feeders more often.
- Brown, beige, or off-white sugar. The color derives in part from iron, for which nectar-feeding birds have a very low tolerance (4,5). Even a little extra iron over time can build up to lethal levels in the birds’ bodies. Refined white sugar has had the trace iron removed to make it a more attractive product, which incidentally makes it safer for hummingbirds. Unfortunately for those of us who try to shop green, lightly refined organic sugar contains several times as much iron as conventional white sugar, so it’s probably not safe for hummingbirds.
- Honey. It’s a natural food, but only if you’re a honeybee. Honey-water diets have been linked with fatal yeast infections (candidiasis) in captive hummingbirds (3), and similar infections have been reported in wild ones. Honey belongs on your biscuits, not in your hummingbird feeders.
- Commercial “instant nectar” and “hummingbird food” products. Most contain unnatural and unnecessary additives such as dyes, preservatives, and/or flavors that, despite what manufacturers and retailers may claim or imply, have never been tested or approved as safe for hummingbirds. Those products without additives are grossly overpriced boxes or bags of sugar.
- Artificial and non-nutritive sweeteners. This includes saccharin (Sweet’N Low®), aspartame (Equal®, NutraSweet®), sucralose (Splenda®), stevia (Truvia®, PureVia®), monkfruit or lo han (Nectresse®), acesulfame potassium (acesulfame-K), erythritol, and xylitol. These sweeteners do not provide the calories (energy) that hummingbirds need to survive.
- Nutritional supplements. The nectar of hummingbird flowers is little more than sugar water anyway (1), and anything else you add can cause premature spoilage and other problems. This includes commercial diets for captive hummingbirds, protein powder, liquid vitamins, fruit juice (except a teaspoon or two of natural juice concentrate for color), vanilla or orange extract, herbal extracts, Jell-O, and Gatorade. Hummingbirds are resourceful and efficient hunters, even in winter, but you can provide a safe protein/vitamin boost by raising fruit flies in jars or starting a compost pile. For minerals to help nesting females build strong eggshells, offer clean ashes from natural wood (no synthetic logs, paper, trash, etc.).
1. Nicolson, S. W. and P. A. Fleming. 2003. Nectar as food for birds: the physiological consequences of drinking dilute sugar solutions. Plant Systematics and Evolution 238(1-4):139-153. (PDF)
2. Lotz, Chris N. and Carlos Martínez del Rio. 2004. The ability of rufous hummingbirds Selasphorus rufus to dilute and concentrate urine. Journal of Avian Biology 35(1):54–62.
3. Orr, K.A. and M. E. Fowler. 2001. 18: Order Trochiliformes (Hummingbirds). In Biology, Medicine, and Surgery of South American Wild Animals, Murray E. Fowler, Zalmir S. Cubas Eds. Iowa State University Press, Ames, Iowa.
4. 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.
5. Ketz-Riley, C.J. and C. Sanchez. 2015. Chapter 26: Trochiliformes (Hummingbirds). Pp. 209-213 in Fowler’s Zoo and Wild Animal Medicine, Volume 8, R.E. Miller, M.E. Fowler eds. Elsevier (Saunders).