HOW TO MAINTAIN YOUR FEEDERS
1. NECTAR
The correct nectar solution is 4 parts water to 1 part white sugar. For example, I often use 2 cups of water and one-half cup sugar. Boil these together for a minute or two to ensure a clear solution, and to kill bacteria. Cool, then fill feeders.
Do not use food coloring, honey, brown sugar, preservatives, or sugar substitutes. These may be harmful to hummers.
2. CHANGE THE NECTAR EVERY FEW DAYS
Twice a week in hot weather, once a week minimum in cool weather. Change it even if it is not being used. Yes, you waste a lot of sugar water, but molds develop fast and can be harmful to hummers. The feeder may be being used without your knowledge. Once, a female hummer came to my feeder only once a day, about 3 pm. If I had missed that visit, I'd have thought the feeder wasn't being used.
Keep a LOG of when the nectar was last changed.
3. KEEP YOUR FEEDERS SCRUPULOUSLY CLEAN!
Saucer-type feeders are much easier to clean. For the other types, buy some brushes (bathroom Q-tips or toothbrushes work well on some feeders) and scrub all parts of the feeder, inside and out, looking especially for black mold. Just use hot water and brushes; if this is done frequently (each time you change the nectar), no disinfectant should be necessary. (There is some evidence suggesting bleach may leach harmful chemicals from plastic feeders.) Some makers recommend a 50-50 solution of vinegar and water, which is then rinsed out.
Finally... it helps to buy new feeders once in a while. :)
WHERE HAVE MY HUMMERS GONE?
Sometimes hummingbirds seem to disappear for a while, especially in June. This is the time when females are sitting on eggs or feeding nestlings. Lots of insects may be hatching out, and new flowers coming into bloom, so visits to the feeder may be less necessary. The nest may be some distance from the feeder, again reducing the number of visits. Males at this time may be wandering around, perhaps testing new feeding areas, perhaps looking for other mates. In any case, do not lose hope, the Hummers Will Return! Eventually, females may bring their young to the feeder, and both sexes may come back looking to mate again.
For more information, see Lanny Chambers' site, www.hummingbirds.net , or Bill Hilton's www.rubythroat.org . Both are very excellent and informative websites.