Porcupine

Zoology with: Porcupines, one quill for The VALiens!

Porcupines are rodents with a coat of sharp spines, or quills, that defend and camouflage them from predators. They are indigenous to the Americas, southern Asia, and Africa. Porcupines are the third largest of the rodents, behind the capybara and the beaver. Most porcupines are about 25–36 in (63–91 cm) long, with an 8–10 in (20–25 cm) long tail. Weighing between 12–35 lb (5.4–16 kg), they are rounded, large and slow. Porcupines come in various shades of brown, grey, and the unusual white. Porcupines’ spiny protection resembles that of the unrelated erinaceomorph hedgehogs and monotreme echidnas.

Quills

Quills come in varying lengths and colors, depending on the animal’s age and species.

Porcupines’ quills, or spines, take on various forms, depending on the species, but all are modified hairs coated with thick plates of keratin, and they are embedded in the skin musculature. Old World porcupines (Hystricidae) have quills embedded in clusters, whereas in New World porcupines (Erethizontidae), single quills are interspersed with bristles, underfur and hair.

Quills are released by contact with them, or they may drop out when the porcupine shakes its body, but cannot be projected at attackers. New quills grow to replace lost ones. From ancient times, it was believed that porcupines could throw their quills at an enemy, but this has long been refuted.

Habitat

Porcupines occupy a short range of habitats in tropical and temperate parts of Asia, Southern Europe, Africa, and North and South America. Porcupines live in forests, deserts, rocky outcrops and hillsides. Some New World porcupines live in trees, but Old World porcupines stay on the rocks. Porcupines can be found on rocky areas up to 3,700 m (12,100 ft) high. Porcupines are generally nocturnal but are occasionally active during daylight.

The Behaviour

Female pre-copulation

In July/August, as the mating season approached, the female porcupine would often rub her genitals on structures such as food and water dishes, sticks, and the cage wire. As the season progresses she accepted and sought more frequent tactile stimulation (presumably from the human investigators).

As the mating season approached, young females become more nervous and excited and put more “vim, vigor and action” into their activities. They would even “seize, straddle, and ride sticks about the cage” walking erect and stimulating their genitalia with the stick. This period of excitement is followed by a period when the female went off her food, remained close to the male and “moped”. During this period the female even accepted the insertion of a thermometer into the vagina (which she resisted at other times).

Male courtship behaviour

When placed in a cage with a female the male porcupine toured the whole area rubbing everything with his nose. He carefully smelled all items, paying closest attention to objects which have been in contact with the female and the places where she had urinated. He often walked about the cage on three legs, clutching at his genitals with his free left front paw. Like the females, the male rubbed his genitals on objects in the cage, and it appeared that the larger the object the more attractive as a rubbing place.

The authors describe having to remove a one and a half inch spike from the frame of one cage as they feared to animal’s vigorous rubbing would result in injury. Males also indulged in “stick riding” as described for females. Males would often “sing” (Actually described as whining) during this period and became more aggressive with other males.

When the male encountered the female porcupine he smelled her all over, then reared up on his hind legs, his penis fully erect. If the female was not ready she ran away. If she is prepared for mating she also reared up and faced the male, belly-to-belly. In this position most males then sprayed the female with a strong stream of urine (In one case, urine was measured on the lab floor 6 foot 7 inches from the point of discharge), soaking her from head to foot. (Johnnie, a young male, would charge the female from this position, trying to wrestle her to the ground and make sexual contact ventrally. He was never successful.)

She would

  • object vocally
  • strike with her front paws, as though boxing,
  • threaten or try to bite, or
  • shake off the urine and run away.

If ready for mating the female did not object strongly to this shower. This courtship routine may occur several times in the days or weeks leading up to copulation.

Mating

Mating occurs in November or December. While females at the peak of receptivity would accept any male, males required a period of close association with the females before they could mate with them. The male makes sexual contact from behind the female. The spines of both animals were relaxed and lay flat.

His thrusts are of the “usual nature” and were produced by flexing and straightening the knees. Males do not grasp the female in any way. Mating occurred until the male was exhausted. Each time he broke away from the female she would re-establish contact. One younger female made grunting whines throughout. If males refused to co-operate, the female approached a nearby male and acted out the male role in coition with the uninvolved male. Females only remained sexually receptive for a few hours and then rejected males.

Post-copulation

While the pre-copulatory period was described as “warming up”, the post-copulatory period was a “cooling off” time. Females rejected males, engaging in the same activities as for pre-copulation, but in reverse order.

Conclusions

Young children should be banned from the university library basements. Sometimes the most improbable science is also the truest. Never stand close to cage which contains courting porcupines.

— article from wikipedia and paulding.net  —

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