How can porcupines mate

These fights can result in serious injury and even death. Uldis Roze, author of The North American Porcupine, told me that he once interrupted a fight where one losing male was left hanging upside down at the very end of a branch.

Another was missing an ear. The victorious male is rewarded with the opportunity to mate. If the mating takes place in a tree, the male will nudge the female forward on her branch, sniffing to smell when she is ready. The female will make small, sharp, squawking noises as she inches away. This behavior may go on for days. When the female is finally receptive, the male approaches on his hind legs and tail, grunting in low tones. He sprays a heavy stream of urine over her body and head.

She then elevates her hind quarters and curves her tail over her back, exposing the under surface of the tail, which has no quills. They may continue to have repeated copulations over several hours, interspersed with periods of cleaning and rest. Eventually, the female climbs on to another branch and screams back at her mate to end their union. Old World porcupines are one of the few animals on the planet that are monogamous. Female North American porcupines, on the other hand, are only fertile once a year for a period of eight to 12 hours little is known about the mating behaviors of other New World porcupines.

In September, that vaginal closure membrane dissolves. The female then begins secreting odorous vaginal mucus, which, along with her urine, lures males into her territory.

But when the first male arrives, the female is still not ready to ovulate, so he has to wait — this gives time for other males to find her, too. The males will then engage in vicious battles, which can result in scars, missing ears and other injuries, Roze said. A porcupine may have as many as 30, quills. The quills are hairs with barbed tips on the ends. Quills are solid at the tip and base and hollow for most of the shaft.

The porcupine has quills on all parts of its body, except for its stomach. The longest quills are on its rump. The shortest quills are on its cheeks. The porcupine uses its quills for defense. The porcupine cannot shoot its quills. When a predator approaches, the porcupine will turn its back, raise the quills and lash out at the threat with its tail.

If the porcupine hits an animal with its quills, the quills become embedded in the animal. Body heat makes the barbs expand and they become even more deeply embedded in the animal's skin.

How do porcupines reproduce? Very carefully. In reality, the mating ritual of the quill-covered Erethizon dorsatum is quite elaborate, protracted, and … damp.

Males drawn by the smell fight each other in the tree branches and on the ground below her. To induce estrus in the female, the male squirts her with urine, a few drops at a time. Typically, the two then descend the tree to breed. Quills could make mounting the female a prickly proposition. The male then can rest his paws on that surface while doing the deed. Approximately seven months later, the female will give birth—in this species, usually a single offspring. All rights reserved.

This story appears in the August issue of National Geographic magazine.