The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season. More on reading these maps.
This behemoth of a tern—it is as big as a midsize gull—is widely scattered in summer in the U.S. and Canada. It winters mainly along, and south of, our southern shores. Audubon's climate model shows relatively modest changes in winter: a slight loss of the total amount of climatically suitable regions, with an overall shift inland. The summer situation is much more dynamic, however, with major losses forecast in core areas of currently suitable climate and the possibility of newly created range far to the north. Caspian Terns have recently expanded their breeding range into southeastern Alaska, a possible hint of things to come