As discussed in Social Spacing, the collared peccary lives in herds within a home range. Although herds are prone to splintering into subgroups, they remain stable for the majority of the year. Herds are evolutionarily advantageous for this particular species due to a considerable predation risk from large canines and felines. These home ranges are generally accessible by all, except for a core area that is heavily defended by the members of the herd. This, however, is no classical territory. It may be posited that dominant peccaries are mainly responsible for this defense, yet there is actually little evidence of a dominance hierarchy. Sexual monomorphism in males and females, in addition to the utter lack of fighting by males over receptive females lends credence to the hypothesis that peccaries live in an egalitarian society. Food is generally predictable, so there is no need for a peccary to defend resources. In fact, peccaries will exhibit altruistic behavior by allowing other members of the herd to feed beside them. Female peccaries will also allow other offspring besides their own to nurse from them. Cooperation among peccaries is also beneficial when threats are near, and peccaries will alert others of the presence of a predator. Males will also sacrifice themselves for the peccary young. Males and females do not split into separate groups, and they are perfectly content with one another in their herds. Young peccaries tend to stay close by their mothers early in life, and they always stay with the herd, possibly all throughout their lives. There are exceptions, though, as some peccaries will abandon a herd for another, but most are related on the order of half brothers or cousins. Collared peccaries are a closely knit group, doing everything together, including eating, sleeping, and resting.
