Question

why do some birds living in extremely cold climates show migration?
short answer please

Answer 1

Answer:

As winter approaches and the availability of insects and other food drops, the birds move south again. Escaping the cold is a motivating factor but many species, including hummingbirds, can withstand freezing temperatures as long as an adequate supply of food is available

Answer 2

they do this to adapt themselves as in the extreme cold they will be finding it very difficult to breathe , find food , etc .so , they migrate to nearby warm places where they could survive