Tuesday 11 August 2009

Crested Porcupines

Crested porcupine
Hystrix cristata Linnaeus, 1758
Hystricidae; Rodentia; Mammalia; Chordata
Natural History Museum
July 2009

During my rounds as a shelving assistant at the Natural History Museum library, I often go to the Mammal Sectional Library, just off the General/Zoology Library where the majority of my work is. After you push through the double doors into the library, before the rows of specialised mammalogical books and journals hits you, you see two mounted crested porcupines. The above photo depicts one of them.

Porcupines are familiar to most people as spiny, pig-like animals. They are more widely known than hedgehogs (see previous post), as some form of porcupine or another are found in North and South America, Europe, Asia and Africa. Hedgehogs are restricted to the latter three continents. The porcupines in the Americas (the New World porcupines) are quite unrelated to the Old World group. Although both classed as hystricomorph rodents (belonging to the same group as, amongst others, capybaras, maras, guinea pigs, chinchillas and coypus), they do not form a monophyletic group (one with a single origin), forming two separate families: Erethizontidae for the New World porcupines; and Hystricidae for the Old World porcupines.

Crested porcupine
Linton Zoo
July 2009

The Hystricidae consists of two main types of animal, in three genera: Hystrix are the crested porcupines; the genera Trichys and Atherurus are the brush-tailed porcupines. Hystrix (meaning 'hairy pig') is the most widely distributed genus, with members in Europe, Africa and Asia. They may not be native to Europe, however (see below). The crested porcupines, as a group, are known for their black-and-white spines and their elongated nuchal crests.

Crested porcupines
Linton Zoo

Most predators do not mess with a porcupine more than once. A flustered porcupine will erect its quills and rattle the hollow spines in its tail as a visual and auditory warning to any potential foes. If the enemy doesn't retreat, the porcupine turns away from it and slowly backs into the predator's face. This is usually enough to deter all but the most determined, and foolhardy, of foes. Should they not retreat, the next thing the attacker knows is a face full of quills. The porcupine cannot shoot them, contrary to popular belief, but they are easily detached, and the ends are barbed, so once embedded in the, often sensitive, flesh, they are hard to remove. A lesson learned the hard way for many a predator.

Crested porcupine mandible
Natural History Museum
March 2008
The above mandible is from Pleistocene Europe. The mammalian fauna of Europe was different to today's, not only through completely extinct taxa, like mammoths and sabre-toothed cats, but also those which are still extant in other parts of the globe. Spotted hyaenas (Crocuta crocuta), hippopotamuses (Hippopotamus amphibius) and lions (Panthera leo) not only roamed ancient Europe, but also reached Britain. It's likely that the periods of glaciation that punctuated the late Pleistocene, known colloquially as the Ice Age, saw the retraction of their ranges into Africa (and Asia). The crested porcupine is another one of these animals; however, they may have clung on to warmer areas of Italy and Sicily. It is also likely that they were brought to these areas by the Ancient Romans as a food source, from northern Africa, where they are certainly native. I like to think that, like genets (Genetta genetta) and Egyptian mongooses (Herpestes ichneumon), the status of the crested porcupine in Europe is native, not introduced.


Zach said...

Waaaitasecond. Are you saying that the term "porcupine" is paraphyletic? That two separate families of rodents evolved quills?

m said...

Yup, that's what I'm saying. Both Erethizontidae and Hystricidae are in the infraorder Hystricognathi, but the Hystricidae group with African endemic rodents in the families Bathyergidae (like the naked mole rat), Petromuridae (dassie rat) and Thryonomyidae (cane rats), while the Erethizontidae group with 10 families of New World endemics. The structure of the quills is different in both types, and there are other spined rodents to which the quills might be similar. For example the family Echimyidae consists of medium-sized to large rat-like rodents with spines on most of their bodies; they are called spiny rats, and belong to the same parvorder (Phiomorpha) as the New World porcupines. Hope I've cleared that up for you!

Zachary Miller said...