Elegant Engineering Over Sabino Creek

Photos and Text by Mark Hengesbaugh

A Bell’s Vireo incubates eggs in a nest suspended over Sabino Creek.

Though they are listed as a “species of concern” in the Sabino/Tanque Verde watershed by Tucson Audubon—along with Elf Owl, Abert’s Towhee and Gilded Flicker—Bell’s Vireos are abundant in the recreation area. Vireo habitat wasn’t always so healthy along this riparian corridor. Ten years ago the ash tree that supports this nest was surrounded by a dense thicket of fast-growing 25-foot tall alien canes—Arundo donax, or Giant Reed—that had shaded out and killed nearly every other tree in it’s path. We never saw a vireo—or any perching bird—attempt to make a nest in those alien canes. It’s an example of the way invasive plants reduce opportunities for reproductive success of the native wildlife.