Over 300 species of hummingbirds live in the western hemisphere, the only part of the world these beautiful birds are found. Hummingbirds have a lifespan of about 10 years and live on a diet of nectar and insects. Their high metabolism demands that they eat from one-half to twice their weight in nectar daily. At night, these birds go into torpor, a slowed metabolic state in which their normally very high body temperature plummets to within a few degrees of air temperature.
Seven hummingbird species breed in the western U.S. and Canada. The species most commonly seen on the North Coast are Annas, Allens and rufous hummingbirds. Rarely seen in our area are black-chinned, calliope, and costas hummingbirds. Allens and rufous hummingbirds breed along the Pacific coast and most migrate south in winter. Annas hummingbirds are year-round residents. The nesting season is in late winter and spring, and many migrate in summer to inland mountains, where they congregate in areas with high densities of blossoms.
Flowers that attract hummingbirds are typically red and tube-shaped. They are perennials with flowers that have reflexed petals and produce copious amounts of nectar. People have long noticed hummingbirds attraction to red. However, pollination biologists question whether this is an innate preference or rather a learned association. Research has shown that hummingbirds learn to associate colors with food sources. They can learn which color of feeder solution contains sugar and will continue to choose that color after the sugar solution has been replaced with colored water. One researcher found that hummingbirds feeding on red-flowering currant (Ribes anguineum) preferred red sugar solution while those feeding on tree tobacco (Nicotiana glauca) preferred yellow. A study in Mexico showed that hummingbirds color preferences changed monthly, with different species preferring the colors of the flowers they were feeding on at the time.
The question is, which came first: the red flowers or the hummingbirds fascination with red? Some botanists theorize that color preference discourages the deposition of pollen on stigmas of unrelated plants.
A fascinating study involved two species of monkeyflowers (Mimulus). Both species have red and orange flowers with a yellow-flowered mutant form. Bumblebees strongly preferred the yellow form, while hummingbirds tended to avoid yellow flowers and preferred orange and red. This study shows that partial reproductive isolation originated from the pollinators preferences.
Over 130 species of plants pollinated by hummingbirds are native to the western U.S. and Canada; more than 80 are California natives. In California, 15% of species in the snapdragon family (Scrophulariaceae) have hummingbird-type flowers. In the eastern U.S., where only one hummingbird species lives, only 19 species of flowers are known to rely on hummingbirds for cross-pollination. Most hummingbird-pollinated plants occur in bee-pollinated genera, such as larkspur (Delphinium), which is a genus with predominantly blue, bee-pollinated flowers. Bird-pollinated plants are thought to have evolved mostly from bee-pollinated ancestors.
Below is a list of North Coast native plant species with hummingbird-attracting flowers.
There are many non-native ornamentals visited by hummingbirds, but few are as favored as pineapple sage (Salvia elegans), which flowers in winter on the North Coast when Annas hummingbirds are dependent upon our gardens and feeders for nectar. Fuchsias and ornamental Penstemon with red flowers are also favorites in winter.
Another way of attracting hummingbirds to your yard is to hang a feeder. For feeder solution, make a supersaturated sugar syrup by adding cane sugar to boiling water until no more will dissolve. The best feeders are those with perches which allow the birds to spend less energy than those which they must hover at while feeding. Place your feeder near a window but well out of reach of housecats.