Morphological and Ecological Response to Human Impacts in Calypte anna

Chantal Olsen


The Anna’s Hummingbird is native to Southern California.In the 1970’s, it expanded it its territories northward to Alaska1. These hummingbirds are suspected to be residents of the Northwest and are only able to do so because of the increased popularity of hummingbird feeders. Repercussions of such a human influence is thus far unknown. This research investigates the possibility of rapid evolution in the Anna’s Hummingbird as an ecological response to the humming bird feeders and the new environmental pressures present in the Pacific Northwest.The cooler climate of the Pacific Northwest selects for a larger body size than Southern California. Therefore, I hypothesized that the wing, beak, tail, and weight measurements of resident Washington Anna’s hummingbirds will be larger than those of specimens native to Southern California. A heavy reliance on sugar water from hummingbird is suspected of the Washington residents, especially during the months without flower blooms. This will be determined through stable isotope analysis of carbon from breast feather samples.