Yes, some mockingbirds actually do migrate north for the winter (I looked it up). Here is your explanation, then. Speaking of migration, after doing a bit of research, I found that I’d only really have to worry about Tina not sticking around for the winter. Hummingbirds usually go to Central and South America for the winter. Of course, they start their migration in September, so it’s a bit late now… I guess Tina’s staying with us this winter.