White-necked Jacobin male hummingbird (IMAGE) Cornell University Caption Both male and female White-necked Jacobins fan their tails during courtship or aggressive interactions. Because this bird also has its wings partially raised it's likely an aggressive stance. Credit Photo by Brian Sullivan/Macaulay Library at the Cornell Lab of Ornithology. Usage Restrictions Only for use with stories about this research. License Licensed content 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.