Question

Birds swell their feather in winter give reason

Answer 1

hey.....
When the birds swell their feathers, they are able to enclose air in the feathers. Air, being a poor conductor of heat, so it prevents the loss of heat from the bodies of the birds tothe surroundings and as such they do not feel cold in winter.
hope it helps u.....

Answer 2

Birds feels cold that's why they swell their feathers. By swell their body get insulation and their body got a little warmness.