I was searching online to see some of the migratory paths of some birds and their winter habitats and found some pages for some popular birds etc. It looks that many of their winter habitats include much of North America and some swans stay where they are at year round. Here are some links:

Robin
http://bna.birds.cornell.edu/bna/spe...s/introduction

Mallard
http://bna.birds.cornell.edu/bna/spe...s/introduction

Canada Goose
http://bna.birds.cornell.edu/bna/spe...s/introduction

Mute Swan
http://bna.birds.cornell.edu/bna/spe...s/introduction

If you scroll down on each of these links, it will show maps of their year round habitats.