Feeder Solution Evolution Part I: The basics

The posts lately have been hummingbird heavy, but you can blame the time of year. Both southbound migrants and a few remaining locals—Rufous, Broad-tailed, Black-chinned, Anna’s, Broad-billed, an occasional Calliope, Costa’s, or Violet-crowned, and our yard’s first Lucifer—have been shrieking and jousting outside my living room window every daylight hour, so it’s hard to think about anything else (which makes it hard to get any real work done but also keeps my mind off things I’d rather not dwell on).

This is going to be a heavy post, so I’m dividing it into three parts. If all you’re interested in is what you should/shouldn’t put in your hummingbird feeder, you needn’t read any further than the end of this installment. If you’re curious about how these recommendations came about—the science and history behind them—I hope you’ll come back or click through to read the second and third installments.

Let’s kick things off with something happy. Happy, happy, happy. No stress, no angst.

A young White-eared Hummingbird drowses in the sun

A young White-eared Hummingbird drowses in the sun.

Okay, down to business. At the request of my friend and colleague Laura Erickson, who writes and edits for the Cornell Laboratory of Ornithology, I’m finally tackling this long-neglected and often controversial topic. Here is what you need to fill your hummingbird feeder:

1. White sugar.

  • Sucrose (a.k.a. white table sugar) is the main sugar in the sap of plants and also in the nectar of hummingbird-pollinated flowers (1). We squeeze sugar cane and sugar beets to get our sucrose, and hummingbirds drink nectar, sap, and properly made feeder solutions to get theirs. It does not give them diabetes. It will not rot their teeth.
  • If ordinary granulated sugar doesn’t dissolve fast 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).
  • Though pure cane sugar is often recommended over pure beet or blended sugar (which is usually labeled simply as “sugar”) based on the perception that it tastes better to the birds, it takes sophisticated testing for food scientists to distinguish between them. Sugar cane yields somewhat more sugar per acre than sugar beets but uses much more water, displaces more biodiversity, and has to be transported farther (at least in U.S. markets), so beet sugar may be the “greener” choice.

2. Good-quality water.

  • If there’s any reason that you don’t personally drink your tap water (too many minerals, has a funky taste or smell, tested positive for pollutants, etc.), don’t make your hummingbird guests drink it, either. If it’s 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 water without losing their bodies’ 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 list of things you should not put in your hummingbird feeder is a wee bit longer:

  • Honey. It’s a natural food, but only if you’re a honeybee. Bees start with the nectar of flowers not typically used by hummingbirds, modify it with digestive enzymes, then barf it back out and evaporate off most of the water. The final product contains less palatable sugars plus stuff you seriously don’t want to feed to hummingbirds. Once diluted to feeder strength, honey becomes an ideal food for a variety of microbes, including some that can cause disease. 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 feeders.
  • Brown or even brownish sugar. The color derives in part from iron, for which nectarivorous and frugivorous 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, organic sugar is typically not fully refined to pure sucrose, so it’s not safe. Rumors of problems at tropical feeding stations may be related to the use of lightly refined turbinado (“raw”) sugar containing iron, but these reports have yet to be substantiated.
  • Artificial coloring. The vast majority of hummingbird flowers put the color on the outside, not in the nectar. FD&C Red #40 and #3, the dyes used in most “instant nectar” products and the food coloring in your pantry, are like nothing the birds would ever encounter in nature. They may not be dangerous at human consumption levels, but hummingbirds can drink more than 5 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, use a few drops of fruit juice concentrate to tint it.
  • 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. Hummingbirds need the calories. If they get fat, it’s for a good reason, and they won’t stay that way for long (unlike us big sluggish primates.)
  • Commercial “instant nectar” and “hummingbird food” products. Most contain unnatural 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 basically overpriced boxes of extrafine white sugar (see the second bullet point under “White Sugar” above).
  • 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, fruit juice (except a few drops of concentrate to add a little color), Jell-O, Gatorade, Mountain Dew, vanilla extract, and strawberry daiquiri mix. Hummingbirds are really efficient hunters, even in winter, but if you want to supplement their protein/vitamin intake, raise fruit flies in jars or start a compost pile. For minerals during nesting season, offer clean ashes from natural wood (no synthetic logs, paper, trash, etc.).

See this post for a more comprehensive list.

Now that we have the two ingredients, the next step is determining what proportion to mix them in. Though opinions about feeder solutions vary slightly within the hummingbird community, most hummingbird experts still endorse this recipe:

4 parts water

1 part sugar

Good old 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. Hardcore hummingbird fanatics may have sound reasons for using slightly stronger or weaker solutions, but all the average hummingbird host needs to remember is 4 parts clean water + 1 part white sugar.

Stay tuned for part II, the science behind hummingbird feeder solutions.

Resources for this post:

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.

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).

Related posts:

Search of the Week: “if refined sugar is so bad for us, then why do we feed it to hummingbirds?”

Search of the Week: “is molasses ok to feed hummingbirds”

Beet juice in hummingbird feeders? NO!

Search of the Week: “can I give hummingbirds mountain dew”

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24 thoughts on “Feeder Solution Evolution Part I: The basics

  1. Excellent post. I must admit I use a 1:5 solution, but the hums still love it and it keeps the bees away.

    • Thanks, Kathryn. No “admission” necessary! You’re a fellow fanatic who understands when and why to use ratios other than 4:1. I think you’ll enjoy the upcoming installments, too.

  2. Pingback: Search of the Week: “is molasses ok to feed hummingbirds” « Life, Birds, and Everything

  3. I’ve been feeding hummingbirds for years. I have five stations around my house, but even with that a male and female tag team still chase off other hummingbirds. Is there anything I can do to discourage this from happening?

    • Research conducted by a student at the University of Arizona found that tightly clustering feeders was a more effective way to thwart territorial hummingbirds than the traditional advice to spread feeders out. One bird will still try to dominate the cluster, but with its competitors more concentrated it won’t be able to exclude them all at once, allowing some birds to feed while others are being chased.

  4. Uh oh. I’ve been feeding the little guys the light brown cane sugar that’s readily available here in Mexico. It’s definitely not as white as refined sugar and the water does come out the color of Budweiser. Ugh! I’ll switch over immediately. Thanks!

    • OK, so I’ve looked high and low (and I’ll keep looking) but I have not been able to find highly-refined sugar in southern Mexico. Here’s what I’m dealing with: http://i.imgur.com/XsKq2qF.jpg. I’m assuming that this is what you refer to above as the lightly refined turbinado sugar. Have you heard anything more concerning those rumors from the tropical stations? Of course I would love to continue feeding these crazy little punks but the very last thing I want to do is hurt them. What do you think?

      Thanks again!

      • No additional information from tropical feeding stations has come to light, but the veterinary literature suggests that the iron content of lightly refined cane sugars is sufficient to cause iron storage disease if it’s part of a hummingbird’s regular diet. This is a real dilemma, because most residents of the tropics are in the same boat as you are.

        One method of reducing soluble iron that might be practical for home use is to oxidize it into a less soluble form that can be filtered out mechanically. The kitchen approach to this would involve aerating the sugar solution (an aquarium pump and airstone should work) and lowering raising its pH if necessary with a pinch of baking soda to facilitate the reaction, then turning off the air and allowing the solution to settle. This should cause a thin film of brownish iron precipitate to form on the bottom of the container. This page has a rundown of the chemistry involved: Iron removal by physical-chemical ways.

        If you try this, please report back on your results.

      • Thank you so much for following up, Sheri. I was able to get my hands on some refined sugar after all and I will go forth and poison hummingbirds no more! I’m also going to get in touch with the people in my town that I’ve turned on to the feeders and let them know where to find the refined stuff. Turns out that there are some Mexican companies that refine sugar but it’s not very popular in my neck of the woods.

        I did attempt to remove the iron from the solution with the method that you outlined. I did not have any luck but thanks again for your thoughtful response.

  5. I wonder if I can use mineral water instead of filtered water because I read that mineral water can affect the electrolyte balance of the hummingbird. Is it true?

    • Since we don’t know the effect on hummingbirds of mineral salts (mainly calcium and magnesium) in excess of the natural levels found in flower nectar, filtered water would be a safer alternative.

      • Thanks very much for the answer! I read all the study you mention “Lotz, Martínez del Rio & Nicolson 2004”.

        It helped a lot. Im from Rio, Brazil.

        I had not found any studies about this topic. But when I found this website, I found the answer I needed to safely continue feeding the hummingbirds (beija-flor) and bananaquit (cambacicas) that are coming in my house.

        Thanks again!

  6. About removing iron from sugar solutions for hummers, you say “and lowering its pH if necessary with a pinch of baking soda to facilitate the reaction, then turning off the air and allowing the solution to settle.”
    Just in case anyone is keen enough to measure pH in some way, and becomes baffled: adding baking soda (sodium bicarbonate) will RAISE the pH (i.e., make it MORE alkaline!) And this is, in fact, what you need to do. If the pH is LOWERED (i.e. toward more acidic), iron will probably remain mostly in solution. RAISING the pH at least to around 8 or 9) will lead to the precipitation of ferric and ferrous hydroxides, and probably carbonate, which you can then remove.

    • You’re right, of course: the numbers of the pH scale go up, not down, as alkalinity increases. The verb I chose to indicate what happens when you add baking soda to a sugar solution was simply a neurological misfire, and it’s unlikely to cause much bafflement since this issue affects so few people, even fewer of whom would have the means of measuring pH in their kitchens. I do appreciate your confirmation that following the instructions could result in the desired effect of precipitating iron from the solution.

  7. Wonderful information! I recently purchased a supply of Zulka Morena Pure Cane Sugar, the company claims it is somewhere in between white refined table sugar and turbinado. Just wanted your thoughts on using this to feed the hummers, it is very light brown and only slightly more coarse than my white table sugar.

    • Zulka Morena is not white sugar (it’s right there in the name: morena = dark), so no, it’s not safe to feed hummingbirds. The post specifies no “brown or even brownish sugar,” as does this post. Save the Zulka for your coffee and cereal, where that tiny bit of iron-rich molasses adds a delicious flavor.

  8. That was incredibly thorough Thank you so very much! I thought I was doing the right thing by offering organic sugar water but I was wrong, good thing they didn’t like it anyway. At least I was using good water though. Havnt seen very many hummers here in Arizona this year, or bees, it’s very sad.

  9. I understand that using organic sugar may be problematic in terms of iron build-up, etc., but I am very concerned about feeding the birds table sugar which is largely genetically modified, and which may have equally deleterious effects on such tiny, delicate bodies. I found an organic cane sugar that is just slightly off-white and am wondering if that might be okay? I am almost starting to think that if I can’t find a viable organic option, I’m going to scrap the feeder altogether as I worry that I might ultimately be doing something harmful for the birds. What do you reckon?

    • tl,dr: I reckon you should stick to flowers rather than feed the birds a real poison to avoid exposing them to a hypothetical one.

      There is irrefutable evidence that semi-refined organic sugar contains iron and that excess dietary iron can sicken or kill hummingbirds. We don’t yet know what level of supplemental iron from feeder solution is safe, so I recommend erring on the side of caution.

      The same does not hold true for GMO sugar, because there is no evidence that it contains anything more harmful than non-GMO sugar. White table sugar, whether GMO or not, is one of the purest products in your pantry (99.7% sucrose by international standards, the remaining 0.3% consisting mostly of other sugars), and there is no evidence that either the genetic modifications themselves or any differences in pesticide/herbicide applications on GMO crops result in any detectable differences in the final product, much less any health hazards.

      Even non-GMO organic sugarcane is grown at significant cost to the environment, but flowers are the only safe non-GMO organic alternative until non-GMO organic white sugar becomes available.

  10. Unless sugar is labeled Cane Sugar, it is Genetically Modified Beet Sugar which will kill hummingbirds.

    • Read my lips, Ron: There is no evidence that GMO sugar contains anything more harmful than non-GMO sugar. White table sugar, whether GMO or not, is one of the purest products in your pantry (99.7% sucrose by international standards, the remaining 0.3% consisting mostly of other sugars), and there is no evidence that either the genetic modifications themselves or any differences in pesticide/herbicide applications on GMO crops result in any detectable differences in the final product, much less any health hazards.

      Unless and until you can produce some science that supports your oddly specific claim (and refutes observations that hummingbirds have been surviving perfectly well on GMO sugar for almost a decade), I’ll have to assume that you, like so many other well-meaning but misinformed people, are simply making sh*t up in an attempt to infect others with anti-GMO hysteria.

      There are plenty of issues surrounding GMOs that we have every reason to be concerned about, from increased herbicide use on glyphosate-resistant crops to Monsanto’s bullying tactics, but killing hummingbirds is not one of them.

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