Hummingbird feeders are usually shaped like either a tube or a saucer. According to the Cornell University Lab of Ornithology, saucer feeders are better for locations in direct sunlight, since tubes tend to leak nectar in the hot sun. However, avoid placing your feeder in full sunlight if possible to avoid spoilage. Saucer-shaped hummingbird feeders also have feeding ports on the top, which keeps bees and wasps from getting in the nectar.
Size is a more important factor than shape. According to Operation RubyThroat, many first-time buyers purchase hummingbird feeders that are too large. If you already have an established population of hummingbirds, consider purchasing a large model. However, if this is your first time setting out food for hummingbirds, purchase a smaller feeder until you have established a steady population, in order to avoid nectar spoilage. Operation RubyThroat recommends starting with an 8-oz. feeder and progressing to a quart-sized feeder with multiple perches.
Hummingbird feeders may be made out of glass or plastic. Although glass breaks more easily and is heavier, it is also less prone to bacterial buildup than plastic and also very easy to sanitize. Hummingbirds are attracted to the color red, so you will probably notice that many hummingbird feeders are red. You can also hang red ribbons on your feeder or situate it near red flowers to increase your chances of attracting birds. Avoid putting red food coloring in nectar, since it may be harmful to hummingbirds.
Your hummingbird feeder should be easy to clean and maintain, since you need to clean it regularly. Once you have established a steady hummingbird population, the birds should consume all of the nectar in the feeder every two to three days. If they don't, your feeder may be too large. The National Audubon Society recommends hanging several small feeders as opposed to one large one, since hummingbirds tend to be very territorial. Keep the feeders far enough apart that the birds cannot see each other to avoid dominance and competition.