In studies of animal behavior herds give a look at group interaction and group response in times of stress or danger. Individual animals follow the behavior of their immediate neighbors. The herd provides companionship as well as protection to the members.
The term 'herd' is used to describe a group of animals of the same species; commonly, a group of hoofed, grazing mammals. The herd may be a natural formation, as in the case of wild animals, or may be formed by human intervention, as in the case of domestic animals like cattle. Herds offer individual animals companionship, better foraging opportunities and more chances for mating and reproduction. A herd also offers more protection against predators than a solitary animal would otherwise have on its own. In studies of animal behavior herds offer an interesting insight into social hierarchies as well as unplanned and uncoordinated mass behavior.
Mass behaviors in a Herd
The individual animals in the herd copy or imitate the behavior of the other animals in the herd, particularly that of their closest neighbors. As a result, all the herd members behave in a related fashion and this allows the entire herd to respond to an external circumstance in a similar way. The herd then functions together as a single entity, for example, when it moves in a certain direction to get away from an attacking predator or when it travels a certain route for migration. These movements are quite unplanned, with the entire herd moving spontaneously, usually after taking its cue from a lead animal; the lead animal usually has a dominant social role within the herd hierarchy, although the social dynamics may keep changing.
Protection against Predators
A herd, by its sheer size, is a highly visible unit. This makes it easy for it to be targeted by predators. At the same time, given the number of animals in a herd, there is increased vigilance and individual animals stand a higher chance of escaping from a predator. So there are two important factors as to why animals live in herds, self-interest and survival instinct. Each individual animal tries to behave exactly as its neighbor in order to protect itself, and tries to minimize the danger to itself by moving along with the others and trying to get deeper into the herd. So the seemingly coordinated behavior of the herd is mainly due to the uncoordinated movements of panicked, individual animals.
Difference in behavior between domestic herds and wild herds
In studies of animal behavior herds of domestic animals operate differently than herds of wild animals. Domestic herds generally do not have to contend with the same level of threats from predators as wild herds. The dominant animals in a domestic herd are rarely in the forefront when the herd is driven, and they are almost always first in a feeding area. Unlike wild herds, which are usually formed by animals related to one another, domestic herds may or may not be formed of related animals. The composition of domestic herds keeps changing as animals are culled or added. As a result, the social structure keep changing more frequently and there may be more instances of aggression. It is therefore important to introduce new animals with care.