Each spring, herds of caribou migrate from the boreal forests of northern Canada to calving grounds hundreds of kilometers away in the Arctic tundra. But what spurs their migration? Scientists think it may be triggered by snowmelt. Learn more @AGU_Eos: eos.org/articles/snowmelt-se… National Snow and Ice Data Center Mission Antarctica by @MissionAntarctica A @grttme project - Other backups: @Hallotme