>>690058So the picture in OP is somewhere in northern Canada, near the arctic circle. They're prob northern timber wolves, a subspecies of grey wolf. In OP's pic They are walking in that line to save energy.
Wolf packs aren't what they are portrayed to be in fiction. They're usually the parents (alpha male and alpha female) and their offspring. The only reason they're 'alpha' is because they're the parents and thus act dominant to their kids, with the kids naturally wanting to follow the parents anyway.