Grey Vireo (IMAGE) National Evolutionary Synthesis Center (NESCent) Caption Grey vireos (Vireo vicinior) cope with noise by singing longer songs with higher maximum frequencies than their counterparts at quiet sites. In contrast, Plumbeous vireos (Vireo plumbeus) in the same noisy areas sing shorter songs with higher minimum frequencies. Credit Photo by Clinton Francis of the National Evolutionary Synthesis Center. Usage Restrictions None 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.