Earth Notes: Porcupines Return to the Colorado Plateau

Mar 1, 2017

Consider yourself lucky if you see a porcupine on the Colorado Plateau — while keeping your distance, of course.  These famously prickly rodents, once common, were almost wiped out in the region for two main reasons. 

Credit Gilfoto

First, porcupines’ favorite foods include the bark and saplings of valuable timber trees such as ponderosa pines. At the behest of lumber companies, thousands of “porkies” were poisoned, trapped, and hunted during the mid-20th century because their gnawing could kill a tree, or cause it to become deformed and unsuitable for harvesting.

Second, the population of mountain lions — a main natural predator of porcupines — has rebounded after being hunted almost to extinction in northern Arizona. Owls, coyotes, and bobcats eat porcupines, too.

An unintended consequence of porcupine scarcity has been the growth of dense thickets of ponderosa pines, creating unhealthy fire hazards. Without porcupines to thin them, fewer ponderosas grow tall and evenly spaced in the savanna-like settings that better resist insects, disease and catastrophic wildlife.

Porcupines reproduce slowly and neither see well nor move fast. Those near roads are often killed by vehicles.  

But, they’re making a gradual comeback in Arizona, and healthy populations now prevail in New Mexico. The species is found in a wide range of habitats, including grasslands and forests.

Stay on the lookout for girdled tree trunks and denuded branches, signs that a porcupine has been at work.