The Saguaro: Two Hundred Years in the Sonoran Desert

The cactus you are looking at has probably been standing here longer than the United States has been a country.

The saguaro, the defining image of the Sonoran Desert, lives for approximately one hundred fifty to two hundred years. It grows its first arm somewhere between seventy-five and one hundred years into its life, which means the arm you are looking at represents the work of a century. A mature saguaro can reach fifty feet in height and weigh several thousand pounds, most of that weight water held in its accordion-pleated trunk, which expands to absorb moisture after rain.

The saguaro exists nowhere in the world except the Sonoran Desert, in southern Arizona and the adjacent Mexican state of Sonora. This exclusivity is the result of precise ecological requirements: it needs the Sonoran Desert's specific combination of summer rain, mild winter temperatures, and elevation. A few miles north or south, a few hundred feet higher or lower, and the saguaro does not grow.

The cactus wren, the elf owl, and the Gila woodpecker all depend on saguaro cavities for nesting. After a Gila woodpecker excavates and abandons a cavity, other species move in. A single large saguaro can function as an apartment building for multiple species over the course of its long life.

The Tohono O'odham harvest saguaro fruit each summer using traditional long poles, in a ceremony that marks the O'odham new year. Arizona state law makes it a serious offense to harm or remove a saguaro without a permit.