Becuase of some insects
If it does not migrate it stays where it was in the summer.
Depending on species and habitat, they may or may not.
Like most bird species - they migrate to warmer areas during winter - and return to their native country in the spring.
no the raven bird is not a tundra birat AT ALL !
If you are referring to a species of bird, it is one word, bluebird - "the bluebird species migrate this time of year". If you are referring to the colour of a bird, it is two - "that blue bird keeps coming back".
Most species of finch migrate, but some, like the house finch, do not.
Permafrost helps bird populations by this process: Deeply frozen ground prevents surface water from soaking into the soil. Surface water forms pools for invertebrates like misquitos. The birds that migrate to the tundra eat these small invertebrates.
Probably mainly bird life.
a ground hog like animal. the migration is it makes shadows of its-self
any kind of bird . they all migrate to the north during the winter and the south during the summer .
Some species, like the white crowned and white throated migrate, others, like the song sparrow, do not.
Swans, and quite a lot of bird species, will migrate southwards to escape the worst of the winter weather.