Annual growth rings indicate the animal's age. Both rams and ewes use their horns as tools to break open cactus, which they consume, and for fighting. On Cabeza a few plants that bighorn are known to forage are ironwood, paloverde, mormon tea, brittlebush, and big galleta. Social Life Rams battle to determine the dominant animal, which then gains possession of the ewes. Facing each other, rams charge head-on from distances of 20 feet or more, crashing their massive horns together with tremendous impact, until one or the other ceases.
Bighorns live in separate ram and ewe bands most of the year.
Gestation lasts about 6 months, and the lambs are usually born in late winter. In the late 1800s and early 1900s bighorn sheep populations rapidly declined. Domestic cattle and sheep, along with wild horses and burros, competed with bighorns, especially at waterholes. Domestic stock also introduced diseases to bighorn populations. Cabeza Prieta NWR's bighorn, like other Arizona bighorn, suffer from chronic sinusitis caused by a bot fly and the disease can be fatal.