In a science fiction setting, however, especially one without FTL, hibernation becomes an asset. Hibernators use substantially less life support. Hohmann transfer orbits become much more feasible. Moreover, since hibernating mammals tend to be small-bodied (bears aren't true hibernators), you can pack more of them per ship.
So... in an anthropomorphic space setting, it's entirely plausible that, the further out you go, the more the population tends to favor mice, bats, ground squirrels and the like.