ECOVIEWS: Porcupines have a point to make
The black dwarf porcupine that lives in Brazilian rainforests south of the Amazon River is a species I seldom talk, write, or even think about. Then again, neither do scientists who study porcupines. An authoritative book on porcupines states that “nothing is known of their life in the wild” aside from the limited knowledge that these little porcupines have a long prehensile tail that is useful for holding onto limbs as they climb through the trees.
This is only one of the world’s 26 or more different kinds of porcupines, some of which have been well studied by behaviorists and ecologists. “Porcupines: The Animal Answer Guide” (Johns Hopkins University Press; 2012; paperback, $24.95) by Uldis Roze provides a wealth of information about this intriguing group of animals.
In the typical format for this outstanding series of books, more than 100 questions on basic biological topics such as porcupine colors, behavior, reproduction, and ecology are asked and answered. For example, “Porcupine Behavior” includes such questions as “Do porcupines bite?” “Do porcupines play?” and “How fast can porcupines run?”
Porcupines are near the top of my list of animals with admirable character and other fine qualities. They don’t pick fights with other animals, and they aren’t bullies. But they are not pushovers either. Porcupines are usually the victors, as long as they stay away from highways. Porcupines are slow-moving mammals. After all, what’s the rush? Even if a predator overtakes you, it will soon find it should have tried to eat something else. According to Roze’s book, North American porcupine males will engage in combat with other males during the mating season in the fall. A porcupine fight sounds like a dreadful event, with the two contestants using their quills as well as their teeth. The loser is often the one that gets pushed off a limb at the top of a tall tree, a common arena for such fights. The savage teeth-biting among males during combat is a conundrum to scientists who study them, because when picked up by humans they “almost never bite.”
What are the biggest and smallest porcupines? The largest, the crested porcupines, are found in the Old World, including Africa, Europe, and Asia, and can weigh more than 50 pounds. All are terrestrial. The single porcupine species found in the United States and Canada (and the most thoroughly studied species) is the so-called North American porcupine. It will travel overland but is very much at home in trees. Although this is the largest porcupine species in the Western Hemisphere, few weigh in at more than 20 pounds. The several species of dwarf porcupines of South America are small creatures that may weigh only a couple of pounds as adults.
In answering the question “what do porcupines eat?” the author notes that all species of porcupines are herbivores. Leaves and bark are staples throughout the year, whereas buds and fruit may be focused on seasonally. One dietary phenomenon among porcupines, a liking for sodium, can create a problem both for humans and for porcupines. In areas where salt is commonly used for snow and ice removal, many road kills occur when porcupines go out on to highways to acquire sodium. On the other side of the ledger, the adhesive materials used to make plywood are high in salt content. Porcupines chew the wood to consume the sodium, behavior that is not popular with people who have outdoor wooden structures. Electrical wiring on the underside of northern vehicles has high sodium levels from being coated with highway salt during winter snow removal. Salty wires, highly desirable to a porcupine on a high-sodium diet, can take a beating from the animal’s strong teeth.
The porcupine question-and-answer book is full of interesting facts about these unusual animals. But the last question in the book, “what don’t we know about porcupines?” makes the point that with porcupines, as with other animals and plants, many of Mother Nature’s mysteries remain just that - mysteries.
Whit Gibbons is an ecologist and environmental educator with the University of Georgia’s Savannah River Ecology Laboratory.