Robins live many places year round. At least they can be found all year, whether or not they are resident birds or ones that move in from colder climates while summer ones move out I believe is often debated. What I have noticed is that we have an abundance of them here around the Front Range this winter.

This flock of about 20-30 individuals, along with the cedar waxwings (which I have also seen more of than I ever have before) picked the dozen or so hawthorn trees around our apartment clean back in December.

And this was a group of about 15 hanging out around Cherry Creek south of Denver last weekend. There was also some Townsend's solitaires with them, which I have never seen that far east and low in elevation before.