How Do Porcupines Make Love?

by Wendy Cooper
Australian National University
Canberra, ACT, Australia

A porcupine. Photo: U.S. National Park Service.

How do porcupines make love? You would probably think the answer is "very carefully," but you would probably be wrong.

The answer is more improbable and much more bizarre than that. While browsing in the basement of the Australian National University library one day, I came across two papers (see references below) which described in great detail the details of the porcupine’s sex life. The information contained in these papers is of such great importance it is paraphrased and presented here. The next time a friend asks you how porcupines make love, you can set them straight by describing these events (in as much detail as you dare).

The Animals

The porcupines in the study were part of a colony kept at the Biology Department at the University of Buffalo during the 1940s. The colony consisted of 5 females (Maudie, Nightie, Prickles, Snooks and Skeezix) and 3 males (Old Dad, Pinkie,[1] and Johnnie).

Female pre-copulation

It was noted that the animals of both sexes objected to being stroked or having their feet, tail base, or genitals touched by the authors. 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 progressed she sought and accepted 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 was followed by a stage 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 that had 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 that the animal’s vigorous rubbing would result in injury. Males also indulged in "stick riding" as described for females. Males would often "sing"[2] 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 was 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,[3] soaking her from head to foot.[4] She would either 1) object vocally, 2) strike with her front paws, as though boxing, 3) threaten or try to bite, or 4) shake off the urine and run away. If ready for mating the female did not object strongly to this shower. This courtship routine occurred several times in the days or weeks leading up to copulation.


Mating occurred 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 would mate with them. The male made sexual contact from behind the female. The spines of both animals were relaxed and lay flat. His thrusts were of the "usual nature" and were produced by flexing and straightening the knees. Males did not grasp the female in any way. Mating continued until the male was exhausted. Each time he broke away from the female she would re-establish contact. One younger female made grunting and whining sounds 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.


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.


1. Young children should be banned from university library basements.

2. Sometimes the most improbable science is also the truest.

3. Never stand close to a cage that contains courting porcupines.


1. He was not pink at all, but albino.

2. Actually described as whining.

3. In one case, urine was measured on the lab floor 6 foot 7 inches from the point of discharge.

4. Johnnie (a young and inexperienced male) would charge the female from this position, trying to wrestle her to the ground and make sexual contact ventrally. He was never successful.


"The Sex Reactions of Porcupines (Erethizon d. dorsatum) Before and After Copulation," Albert R. Shadle, Marilyn Smelzer & Margery Metz, Journal of Mammalogy, vol. 27, no. 2, 1946, pp. 116-21.

"Copulation in the Porcupine," Albert R. Shadle, Journal of Wildlife Management, vol. 10, no. 2, 1946, pp. 159-62.

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