Collared Flycatcher (IMAGE) University of Helsinki Caption Collared flycatchers are small passerine birds that are expanding their European breeding range towards the north in response to global climate warming. Credit Eryn McFarlane Usage Restrictions Copyright Eryn McFarlane 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.