How can a poorly insulated mammal that evolved in the tropical jungles of South America not only survive but thrive in the extreme conditions of the American Southwest? By doing what comes naturally.
To escape the summer heat, javelinas feed mainly at dawn and dusk. When water gets scarce, they subsist on the mushy pulp of prickly pear cactus. In cold weather, they rest, huddled together for warmth. They eat whatever is available fruit, nuts, roots and tubers. They are highly social but not rigidly hierarchical or particularly territorial. Occasionally they are preyed upon by mountain lions and bears, but they are capable of intimidating coyotes and dogs. Their impressive canine teeth can become formidable weapons, as anyone who tries to corner one of them (or who does so inadvertently) may discover.
Javelinas and people have been expanding their range in southern Arizona. As subdivisions intrude farther and farther into javelina habitat, the animals are perceived increasingly as nuisances because they root in gardens, scrap with dogs and occasionally bite homeowners. Coexistence may be possible only if, in sparsely developed areas, islands of habitat are preserved areas large enough to enable javelinas to pursue their traditional ways without encountering people. When wildlife rehabilitator Susan Simpson of Green Valley, Arizona, hears people complain about javelinas, she has a stock response: "Having them around is a bonus, not a penalty, for living here."