I read it here on FR a few years ago that some hummingbirds, who historically migrate great distances up and down North America, are no longer making the migration. Instead they hang out where the food is.
Humans are causing this divergence by feeding them.
It is theorized that if people keep feeding them they will someday split into a unique subspecies.
Perhaps a fatter and lazier subspecies.
I actually think ours don’t migrate. We always have at least one bull hummer who ‘runs’ the yard. They are very territorial. They seem to be here winter or summer.