do birds get winter coats?

I was watching this Golden Whistler, he looks very much like my dogs at the moment. They are molting and then getting their winter coat.

So, do birds get different feathers to cope with cold winters? Other than fluffing up to increase the insulation using air trapped under feathers, do they grow a more insulating kind of down?

I did a bit of internet searching, and found this article.

http://web.extension.illinois.edu/ccdms/wildthings/111116.html