It is late July in southern Arizona’s Saguaro National Park and the scorching
sun bakes the rocky earth Four turkey vultures circle in the cloudless sky
I t is late July in southern Arizona’s Saguaro National Park and the scorching sun bakes the rocky earth Four turkey vultures circle in the cloudless sky scanning a landscape dotted with prickly creosote shrubs slender spiked ocotillo tall saguaro cacti and dozens of other desert plants Suddenly a scent catches the vultures attention They flap their wings to change direction and begin descending More than a mile 1 6 km below is the source of the
