Arizona is one of the most biologically diverse states, a status attributed to its highly varied geography. The state encompasses portions of four major North American deserts: the Sonoran, Chihuahuan, Mojave, and Great Basin. This vast landscape transitions dramatically from low-lying desert valleys to high-altitude mountain ranges exceeding 12,000 feet. This range creates distinct ecological zones, including riparian systems, grasslands, and coniferous forests, supporting nearly 900 vertebrate species.
Iconic Mammals of the Desert and Mountains
The Collared Peccary, commonly known as the javelina, is a recognizable resident of the desert floor, often mistaken for a pig. Covered in coarse, grizzled hair, these animals typically weigh between 40 and 60 pounds. Javelina are highly social, moving in herds up to 20 or more, and are frequently sighted browsing on prickly pear cactus and mesquite beans.
The coyote is a highly adaptable and common mammal found statewide in nearly every habitat, from deserts to high-elevation grasslands. These medium-sized canids are distinguished by their bushy, black-tipped tail and pointed ears. They are opportunistic hunters and scavengers, managing rodent and rabbit populations across their range.
In high-elevation woodlands, the Mule Deer is the most widespread large deer species, identified by its large, mule-like ears and a black-tipped tail. These deer browse on shrubs and forbs, using their large ears to detect predators. The smaller White-tailed Deer subspecies, the Coues deer, is found in the southeastern quarter of the state, distinguished by a solid white tail held high when running.
The Desert Bighorn Sheep is a symbol of Arizona’s rugged mountains, adapted to arid, steep environments. These robust sheep can go for extended periods without drinking water, relying on moisture from the plants they consume. Males (rams) possess massive, curling horns that can weigh over 30 pounds, while ewes have smaller, straighter horns. They are often seen navigating sheer cliffs and canyons.
Venomous Reptiles and Arthropods Requiring Caution
Arizona is home to 15 species of rattlesnakes, and the Western Diamondback is one of the most commonly encountered. It possesses a distinct diamond pattern on its back and a banded tail ending in a prominent rattle. Rattlesnakes are not aggressive and only strike in defense, using their rattle as a warning when threatened. If encountered, stop, back away slowly, and allow the animal to retreat.
The Gila Monster is a venomous lizard species native to the Sonoran Desert. This large, slow-moving reptile is characterized by beaded skin patterned with black and pink or orange coloration. The Gila Monster’s venom is delivered through chewing. Bites are rare, almost exclusively occurring when the animal is handled or harassed.
Among arthropods, the Arizona Bark Scorpion is the most venomous scorpion in North America, common in central and southern Arizona. These scorpions are pale tan and slender, often found hiding in rock crevices or under debris. Their sting can cause severe symptoms, including intense pain, numbness, and tingling, particularly in small children or those with compromised immune systems.
Emergency Response
In the event of a rattlesnake bite, immediate medical attention is necessary. Victims should keep the bitten extremity below heart level and remain calm. Avoid common myths, such as applying a tourniquet or attempting to suck out the venom, as these actions can cause more harm. For a bark scorpion sting, severe reactions like trouble breathing or swallowing warrant an emergency room visit.
Managing Interactions with Urban Wildlife
As urban areas expand, human-wildlife encounters become frequent, requiring residents to adopt strategies to minimize conflict. Coyotes and javelina are common visitors to neighborhoods, often drawn in by accessible food sources. Securing trash cans with heavy lids or storing them in a garage until collection helps eliminate a primary attractant.
Feeding wildlife, even indirectly through bird feeders, should be avoided because it causes animals to lose their natural fear of humans and congregate in unsafe areas. Pets, especially small dogs and cats, should be supervised when outdoors, particularly at dawn and dusk, when nocturnal animals like coyotes and bobcats are most active. These animals view pets as potential prey.
Reducing potential hiding spots around a property is an effective deterrent for smaller animals like reptiles and scorpions. Trimming shrubs up from the bottom and clearing wood or rock piles reduces the cool, dark shelter these creatures seek. For homeowners, installing fine-mesh fencing buried several inches underground can create a physical barrier against rattlesnakes.