Herd or Pack?

by Maple

I have encountered a group of fledglings who are on their way to the same location as myself. Something that is confusing me however is that this group seems to be traveling together for safety as a herd might, but my last group encounter were traveling to ensure greater effectiveness as a hunting unit like a pack. So the question persists of weather fledglings travel in herds or packs? It is baffling to consider an animal would travel in both.