Maybe your neighbor has told you about scrambling to build a heated nectar feeder in recent winters to serve hungry Anna’s hummingbirds. Ingenuity and cleverness are evident in the variety of solutions many residents have employed to ensure that visiting hummers can access liquid sugar solutions, despite weeks of frigid winter temperatures in Eastern Washington. Why are we seeing increasing numbers of Anna’s hummingbirds in our snowy cold climate? A key element of biological science study is that there are so many unanswered questions about common life forms, and our local Anna’s Hummingbirds provide a great example.
Some people fear that these feeders are inhibiting a natural migration process, but in fact, Anna’s are a non-migratory species that has recently dramatically expanded its range. Our region hosts two other smaller species of migratory hummingbirds that commonly use backyard nectar feeders: Calliope and Rufus. Both of these migrate south for the winter. To distinguish the larger Anna’s from these other two, look for a ruby-red crown and long rosy throat feathers on the male. Females have a white arc over and behind the eye. Both lack any rufus (orange-brown) color on the breast, sides or tails.
Prior to the 1930’s, Anna’s Hummingbirds were only found along a section of the Pacific coast of North America, breeding from Baja, Mexico, north to California’s San Francisco Bay area. Anna’s relied on nectar from native gooseberry, current, and fuchsia plants, and captured insects and spiders for protein. Since then, it has increased in numbers and successfully expanded its range north to coastal British Columbia and inland to interior B.C., Washington and Oregon. Climate change is one factor in this range expansion. Another driving factor are patterns of increasing human urban and suburban settlement.
Anna’s have effectively expanded their use of a wider variety of nectar resources by using many types of non-native, cultivated plants and hummingbird feeders in yards. Anna’s often take insects or spiders from crevices, spider webs, from the air, or while perched, flying out to “hawk” a midge or fly. By feeding late in the day and storing nectar in its crop, this bird has enough stored energy to make it through a long cold night, sometimes going into torpor, or hibernation.
To date, little field research has been conducted on Washington’s Anna’s populations. We don’t know if our Wenatchee area over-wintering birds are able to successfully breed, nest, and raising young here. It is possible that our over-wintering birds arrive seasonally, either by flying over the Cascades or flying up from the Columbia Gorge. We don’t know if our winter resident birds seek more moderate west-side habitats to nest. In California, birds nest in the winter with young fledging March to May, relying on chaparral shrub bloom and insect for food. Different populations of California birds change their geography after rearing young, moving to higher mountain elevations to access later cycles of plant bloom for nectar. It is probable that Washington birds delay nesting until spring due to more limited winter food availability, but studies have not yet been done.
A powerful way for citizens to assist scientists learn about Anna’s Hummingbirds is now available. National Audubon Society offers “Hummingbirds at Home,” an online citizen science program where people report hummingbird presence and their feeding behavior year-round at a specific location, audubon.org/content/hummingbirds-home. I hope you’ll join me in reporting Anna’s Hummingbirds that use your yard!
Biologist/educator Susan Ballinger works for Chelan-Douglas Land Trust, serving as the 2016 Conservation Fellow. Each fall, she teaches a 12-week Wenatchee Naturalist Course through Wenatchee Valley College Continuing Education.