Anna’s Hummingbird (Calypte anna) Trochilidae
University of Washington, Seattle, WA
January 13, 2013
Robert Niese
This is the only species of hummingbird to overwinter here in the Pacific Northwest — and they’ve only been doing it for a few decades. Scientists believe that human-provided winter nourishment (i.e. hummingbird feeders) are the primary food source for these non-migrating individuals during the winter months.
As such, researchers at the University of Puget Sound are studying these two distinct populations of birds to determine if they might be diverging — genetically and morphologically. With the help of museum specimens dating back to the early 20th century, we are finding that resident populations of hummers here in the PNW are slightly different than their migratory counterparts.
Northwest Naturalist 