(Photograph = western screech owl, Adamphoto)
Introduction
Cacti sustain desert wildlife as food, water, and shelter. Pads and fruits are eaten, flowers feed pollinators, and stored moisture helps animals through dry spells. Birds, lizards, mammals, insects, and bats all use cacti; some raptors and ground-nesters even raise young in them.
The Details
In saguaros, Gila woodpeckers excavate nest cavities in the soft cortex; the outer rind scars over, and the plant usually keeps growing. Later, western screech owls and other birds reuse these cavities.
Cactus wrens weave nests deep in the armament of chollas, where dense spines deter predators.
In the western deserts, the white-throated woodrat readily eats Opuntia flowers and fruits for moisture, pulp, and seeds. It also collects detached spines to ring its midden, creating a sharp barrier against snakes and birds of prey.
Many other animals—coyotes, kangaroo rats, jackrabbits, javelina, and numerous insects—rely on cacti for food and cover. For them, spines are obstacles to navigate rather than absolute defenses, and in some cases, they even confer protection by discouraging larger predators.
Additional Reading: Rodent Population Densities at Organ Pipe National Monument
