April in northern Arizona is heralded by the loud metallic wing trills of broad-tailed hummingbirds returning from winter in the Highlands of Mexico and Central America. They’re joined in late summer by their feisty cousins, rufous hummingbirds, which breed farther north, but linger a while on their way south.
They need to eat more than their body weight each day, so these tiny aerial athletes eat more frequently than almost any other animal and are almost constantly looking for food. All the vitamins, minerals and protein they need come from insects and natural flower nectar. But a short time at a sugar-water feeder gives hungry hummers a useful energy boost.
As with any top athlete, a proper diet is crucial. So when putting out a feeder, use only refined white cane sugar. You can start the season with a 1-to-3 ratio of sugar-to-water to encourage hummers to find you. But once you have a “loyal” following, a reduced ratio of 1-to-4 will help the birds meet their daily energy and water needs.
Avoid using brown and powdered sugar, molasses, honey and commercial nectar mixes, which all contain iron. Hummingbirds evolved on a diet naturally low in iron. Consuming too much can lead to excessive iron build-up in their organs over time, potentially causing liver failure, kidney damage and even death.
And if your home water supply is high in iron, be sure to use distilled or reverse-osmosis water when preparing your backyard hummingbird buffet.
This Earth Note was written by Diane Hope and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.
