Put On Your Boots.

The Saguaro is a familiar part of the Arizona wilderness, it is also a wonderfully secure home for numerous species. But what do those nesting cavities really look like? It is a long time before the Saguaro reveals this secret, when they die they can remain standing for many years. Eventually when the skeleton is revealed the lining of the cavity also appears. These are known as Saguaro Boots, it is the cactus way of protecting itself. When creatures make holes in the cactus, the Saguaro produces a lining in the cavity. Over time it hardens so when the Saguaro dies and the soft material withers away, the boot is left (or right!)