Both sexes actively defend the home range. Collared peccaries fend off adversaries by squaring off, laying back their ears, and clattering their canines. In fight, they charge head on, bite, and occasionally lock jaws. The dorsal rump gland is also used as recognition and identification. The Collared peccary is very dependent on ambient temperature and seasonal changes.
Herds even graze during the daytime to utilize the heat of the sun.
Habitat In South and Central America, the Collared Peccary inhabits tropical rainforests. In the southern United States, herds occur in Saguaro deserts, where they prefer mesquite habitats with an abundance of prickly pear cacti. Collared Peccaries have also become common in residential areas, where they may rely on human handouts for food. They are among the most important big game species in Arizona. Negative Collared Peccaries have readily habituated urban environments, and often frequent locations where they know they will be fed.