A group of whitetail deer is known as a herd. Generally, the females, known as does, herd together with one to three young deer, known as fawns, while the male deer, or bucks, herd together in groups of three to five.
Does tend to stay with their mothers for about a year and then are driven off before the new litter arrives. Buck herds constantly change, as males are always competing against each other to show dominance and attract mates.
While herds do briefly split up during mating season, deer stick together for much of the winter months, as this protects them from wind and enables them to share the same worn paths.