fox sparrows migrating

Over the last week, through blizzard winds and huge snows, a lone Fox Sparrow seemed stranded alone among the Dark-eyed Junco flock sheltering in my feeder garden.  Today, with clearing weather south of here, several Fox Sparrows joined the first one.  They are ground feeders, kicking and hopping in leaf litter to expose bugs and seeds.  With a hard crusty snow cover on much of the ground, some of the hopping motions take maximum energy to be productive!