Submitted by: aka.attrition
This picture floated around the internet some time ago showing a pack of wolves walking single-file through the snow. The wolves appear to be walking in a number of distinct groups within this line and with a single, lone wolf bringing up the rear.
When asked to offer a commentary on this picture most would suggest that the alpha-male is leading the pack with the old and sick at the end of the line falling further and further behind. Behind the leader are the two or three strongest wolves that will one day look to challenge him for leadership. In the middle, making up the bulk of the pack, are the females and younger wolves. They walk in single-file making it easier when going through thick snow and creating an obvious trail to follow.