A new model analyzing how birds in western North America will respond to climate change suggests that for most species, regional warming is not as likely to influence population trends as will precipitation changes.  Several past studies have found that temperature increases can push some animal species – including birds – into higher latitudes or higher elevations. Few studies, however, have tackled the role that changes in precipitation may cause, according to Matthew Betts, an Oregon State University ecologist and a principal investigator on the study.  “When we think of climate change, we automatically think warmer temperatures,” said Betts, an associate professor in Oregon State’s College of Forestry. “But our analysis found that for many species, it is precipitation that most affects the long-term survival of many bird species.