Bluebird (IMAGE) Penn State Caption The researchers believe the male bluebird, because he had nested in the box earlier in the season, was confused. He made a "place-based decision" to care for the young tree swallows. He was duped because he was hearing begging calls and remembered the box. Credit Julian Avery/Penn State Usage Restrictions Non commercial use only 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.