Sugar water is a substitute for the nectars of hummingbird-pollinated flowers, which provide the birds with energy-rich sugars, water, some electrolyte salts, and little else. Almost everything else their bodies need, including protein, comes from eating insects, spiders, and other small arthropods. (Salvia sp. in my garden, copyright S. L. Williamson)
Hummingbirds do need extra protein in their diets during the nesting and molting seasons. Here are some tips for helping them meet their protein needs:
- Don’t use broad-spectrum pesticides in your yard: Many common yard and garden pests, including aphids, whiteflies, and various annoying gnats and midges, are just the right size for hummingbirds to eat. Even if the birds don’t sicken and die from eating poisoned prey, spraying pesticides destroys an essential source of natural nutrition and makes your yard less attractive to them. Switch to targeted, low-risk remedies for specific pests, such as a hard spray of water under leaves for aphids and various forms of the natural pest pathogen “Bt” (Bacillus thuringiensis) for caterpillars and mosquitoes. Also, beware of purchasing hummingbird flowers from mainstream garden centers. Many of these plants have been unnecessarily treated with the same neonicotinoid pesticides that have been implicated in the terrifying declines of honeybees, native pollinators, and native insect-eating birds.
- Cultivate a compost pile: Fruit flies are attracted to decaying vegetable matter, including fruit rinds and scraps. Garden experts often advise against adding fruit to compost piles/bins in part to discourage fruit flies, but these tiny insects provide excellent hummingbird food while aiding the composting process.
- Grow your own fruit flies: There are lots of recipes on the Web. When a culture matures, just set the container in your garden and open it so the flies can escape.
The one thing you absolutely, positively should never, ever do is add protein supplements to your feeder solution. It’s unnatural, the solution will spoil much faster, and the birds will not like the taste. (Captive hummingbirds drink protein-rich liquid diets, but only because they have no choice. They’d much prefer flower nectar or sugar water for energy and water and a variety of insects and spiders for protein, amino acids, vitamins, minerals, etc.)
More on what to put (and not put) in your hummingbird feeder:
Feeder Solution Evolution, Part I: The Basics
Search of the Week: “is molasses ok to feed hummingbirds”
Feeding Hummingbirds: The dangers of red dye
Beet juice in hummingbird feeders: NO!
Search of the Week: “hummingbirds won’t eat instant nectar”
Search Roundup: Feeding hummingbirds
Keeping hummingbird feeders clean
Life, Birds, and Everything 
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