A European Pied Flycatcher Nesting Box (IMAGE) University of Massachusetts Amherst Caption Using "unique and extensive long-term bird-banding data" over 43 breeding seasons by a small army of dedicated bird banders in Finland, researchers at the University of Helsinki and UMass Amherst found that tits, thrushes, crows, owls and gulls showed the greatest changes in breeding period. Credit Finnish Museum of Natural History/Aleksi Lehikoinen 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.