Anna's Hummingbird (image) University of California - Santa Cruz Share Print E-Mail Caption Webs of mutualistic species often expand as new species are introduced. Here a female Anna's hummingbird visits a Mexican bush sage in a Californian garden. Credit John Thompson Usage Restrictions For use only with news coverage of this research Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.