The Saguaro Cactus, scientifically known as Carnegiea gigantea, is the largest cactus species found in the United States with a towering height of up to 40 feet. In fact, the tallest recorded Saguaro Cactus ever measured was almost 78 feet tall. This spiny, branch-like cactus is only indigenous to the Sonoran Desert, which covers southern Arizona, southeast California, and western Sonora in Mexico. Although it can grow at sea level, its growth is limited to an elevation of approximately 4,000 feet due to freezing temperatures during winter. Interestingly, the Saguaro Cactus only grows on south-facing slopes above 4,000 feet. The cactus plays a crucial role in the desert ecosystem as it serves as an indicator and keystone species by providing food and shelter for various animals.
The Saguaro National Park was initially created by President Herbert Hoover in 1933, as the Saguaro National Monument in the Rincon Mountains. Later on, President John F Kennedy included the Tucson Mountain District to the monument in 1961. Both of these districts are situated on either side of Tucson in Arizona. In 1994, the National Park was established to safeguard the remarkable Sonoran Desert landscapes that are the natural habitat of the Saguaro Cactus. The total area of both the districts combined is 91,327 acres.
The Saguaro Cactus has a unique way of protecting itself during its early years of growth. It forms a symbiotic relationship with fast-growing trees like palo verde, ironwood or mesquite, which are fondly referred to as “nurse trees”. These nurse trees provide shelter and protection to the slow-growing Saguaro Cactus until it is strong enough to survive without them. Interestingly, it takes about 8-10 years for the cactus to grow just 1 to 1.5 inches. Scientists believe that the competition for water and nutrients eventually leads to the demise of the nurse tree as the Saguaro cactus continues to grow.
The Saguaro Cactus serves as a sanctuary for various kinds of wildlife, particularly for the Gila Woodpecker which creates nesting sites by making burrows in the cactus. The cavities formed by the woodpeckers offer a secure haven for animals from predators, and the cactus provides warmth during colder seasons. Abandoned cavities also serve as homes for elf owls, screech owls, purple martins, finches, and sparrows. Moreover, some birds like the Harris’s Hawk construct their nests on the branches of the Saguaro Cactus.
The Saguaro Cactus not only serves as a majestic desert icon, but also serves as a sanctuary for bobcats who need to escape from predators. Bobcats, also known as Lynx Rufus, have thick and padded paws that allow them to climb the cactus without getting harmed by its prickly spines that can grow up to three inches or seven centimeters long. Furthermore, the towering height of the cactus provides an elevated vantage point for these feline creatures to observe their surroundings.
