Porcupine swims with some ducks in the mouth of Brooks River at Naknek Lake, Brooks Camp June 22, 2024 gif created by LunaCre (p 06/23/24 01:44 #12)
Porcupine Fast Facts
* Size: Average 15-20 pounds, some reach 30 pounds.
* Range/Distribution: Forested areas of Alaska.
* Diet: Plants, inner bark of trees.
* Predators: Fisher outside Alaska; wolves, wolverines, coyotes, and lynx sometimes learn how to successfully catch, kill and skin porcupines.
* Reproduction: One per year.
* Remarks: Porcupines evolved in South America and moved into North America about three million years ago during the Great American Interchange, when tectonics pushed the two continents together and a bridge was created in Central America.
Porcupine - North American Porcupine (Erethizon dorsatum):[]
ADF&G Links:[]
Porcupine - Land Mammal Viewing[]
"Description:[]
The North American porcupine is one of the largest rodents in Alaska, second only to the beaver. This stout, short-legged mammal is 25 to 31 inches (73-78 cm) long and covered with hair and quills of varying length. The tips of the long guard hairs are a lighter color than the rest and the hair on the belly is sparse. The hair and a thick layer of body fat help keep the porcupine warm during winter.
The porcupine has an extremely muscular tail that it uses for climbing and defense. The upper surface of the tail is thickly covered with quills while the underside is covered in bristle-like hairs, which aid in climbing. Quills are modified hairs that have microscopic barbs on the tips and are filled with a spongy matrix. Quills from different parts of the body vary in length, flexibility, color, shaft diameter, and barb length. When it is alarmed and its quills are bristled, the porcupine also emits a pungent odor as a warning. Once an animal has tangled with a porcupine, the smell may serve as a deterrent the next time.
Male porcupines often fight each other—using their incisor teeth and quills as weapons— for the opportunity to mate with a receptive female. The winner, usually the largest porcupine, then splashes the female with urine. If she is not ready to mate, she shakes off the urine and leaves. If she is ready, she stays and the male mounts in the traditional posture with the female in front and the male in the rear. She will curl her tail over her back, covering most of the quills.
The average weight of an adult male porcupine ranges from 15 to 18 lbs (7-8.5 kg), but some individuals can weigh up to 30 lbs (13.6 kg). Adult females weigh about two to four lbs (0.9-1.8kg) less than the males. The porcupine has an excellent sense of smell, hearing, and taste, but its eyesight is relatively poor. Porcupines make a wide variety of sounds ranging from whimpers to screams, depending upon the circumstance.
The inner bark of spruce, birch and hemlock and spruce needles are the major winter foods for porcupines in Alaska. In spring and summer, they eat buds and young green leaves of birch, aspen, cottonwood, and willow until the tannin levels build too high to tolerate. Because their foods are very low in sodium, porcupines seek out salt sources such as natural licks, glue which bonds plywood together, human perspiration on tools, road salt, and some paints. Porcupines also feed on shed antlers and the bones of dead animals to obtain sodium and calcium.
Habitat:[]
The common porcupine lives in coniferous, deciduous and mixed forests. It also thrives in scrubby tundra areas and rocky slopes.
Viewing:[]
The porcupine is found throughout all of Alaska except the Alaska Peninsula and Kodiak, Nunivak, and St. Lawrence islands. In wooded areas, porcupines are easy to spot in trees chewing on leaves or waddling across the trail. In northern areas like Nome, willow bark is their primary food, but they can be encountered almost anywhere, from high rocky slopes to tundra meadows."
North American Porcupine Species Profile[]
"General Description:[]
"This stout, short-legged mammal is 25 to 31 inches (73-78 cm) long and is covered with hair (except on the foot pads and nose) and quills of varying length. The tips of the long guard hairs are lighter and give the coat hues of yellow or white. The hair on the belly is sparse and varies from black to brown. The hair and a thick layer of body fat helps keep the porcupine warm during the winter. The tail is extremely muscular and adapted to aid in climbing and defense. The upper surface of the tail is heavily covered with quills, while the underside is covered in bristle-like hairs used to aid in climbing. The quilled pelage of the porcupine makes it unique among North American mammals. Quills cover the body, except on the legs and belly. The quills are modified hairs which have microscopic overlapping sheaths on the tips (functioning like barbs) are filled with a spongy matrix. Quills from different parts of the body vary in length, flexibility, color, shaft diameter, and barb length. The average weight of an adult male porcupine ranges from 22 to 27 pounds (about 10-12 kg), but some individuals can weigh up to 30 pounds (13.6 kg). Adult females weigh 15 to 18 pounds (7-8.5 kg), about ten percent less than the males.
The porcupine has excellent senses of smell, hearing, and taste. Porcupines make a wide variety of sounds ranging from whimpers to screams, depending upon the circumstance.
Growth & Reproduction:[]
Breeding takes place in the fall, usually in September in Alaska. Males seeking receptive females expand their home ranges up to five times the normal size. If more than one male shows interest in the same female, they will fight for the opportunity to mate with the female. Males use their incisor teeth and quills when fighting, and usually the largest and heaviest male wins. The breeding male then splashes the female with urine. If she is not ready to mate, she shakes off the urine and leaves. If she is ready, she stays and the male mounts in the traditional posture with the female in front and the male in the rear. She will curl her tail over her back, covering most of the quills. Males reach sexual maturity at 24 months and females at 12 months.
After a gestation period of about 210 days, only a single young is born. The gestation period is extremely long for a rodent. At birth the young weighs between 1 and 2 pounds (0.5-1.0 kg) and is about 10 inches (25 cm) long. Its eyes are open and its body covered with long grayish-black hairs and quills. Within a matter of hours the quills dry and serve as protection. The young porcupine is then capable of following its mother, although the young will not be able to climb large trees for several weeks. The young are able to eat some vegetation after a few weeks, but the female continues nursing the young for 3.5 months. During the summer the young stay close to their mothers, learning about den sites and food trees, but toward the end of summer they start to spend more time apart. By October, when the female mates again, the young are fully weaned and wander off to face the winter alone. Porcupines are relatively long lived and can live up to about 18 years in the wild.
Porcupines may be active in the day but are mostly nocturnal. During the day they sleep in a tree, a hollow log or among rocks or tree root-wads; they do not build a nest. During severe winter weather they might den up with other porcupines, otherwise they are solitary except for mother and baby. A porcupine has a home range, the size varies in depending on the area, (studies have shown home ranges varying from 25-35 acres, to as much as 70 acres in others). Porcupines they learn the denning sites and seasonal food resources in the area. Porcupines utilize natural cavities, such as rock caves, hollow logs and trees, or even the thicker vegetation in a tree as dens. Porcupines stay active throughout the winter.
Porcupines are primarily arboreal, and spend most of their time in the winter feeding in trees. They are powerful climbers but do occasionally fall from trees. Thirty percent of the animals examined in one study showed evidence of healed fractures indicating that they had fallen out of trees. When climbing, the porcupine uses the stiff bristles on the undersurface of the tail as support. The animal has long, curved front claws which also aid in climbing.
Most carnivores would not pass up a meal of porcupine. However, an encounter between a young inexperienced predator and a porcupine can be a very painful experience. Some unfortunate carnivores have starved to death because a mouthful of quills has prevented them from eating. In an effort to remove the quills, the predator can cause the barbed quills to work into the deep tissues. Predators have different means of killing and eating porcupines. In the Northeast United States, the fisher has learned to specialize on a diet of porcupine. The fisher circles around the porcupine until it can bite its nose. After repeated bites to the nose, the fisher then flips the porcupine over to attack the quill-free belly. The porcupine is then eaten leaving an empty quill-covered skin. This method may also be practiced by lynx, wolves, coyotes, and wolverines which have been recorded eating porcupines in Alaska.
When the porcupine is relaxed, the hair and quills lie flat and point backwards. When threatened, the porcupine draws up the skin of the back to expose quills facing all directions, and it then presents its formidable bristling back. The porcupine tries to keep its back facing the attacker and strikes back and forth with its tail. Contrary to popular belief, a porcupine cannot throw its quills. However, quills are readily dislodged on impact which may give the impression that quills can be thrown.
Porcupines use a combination of warning signals, which also serve to reinforce the lesson a dog or potential predator might learn from an encounter. Porcupines produce a chemical scent from a patch of skin on their backs near the base of their tails called the rosette. Biologist Uldis Roze describes it as having a “penetrating quality similar to the smell of goat or perhaps exotic cheese.” Others compare it to strong, unwashed human body odor, marijuana and coconut. In his book, The North American Porcupine, Roze identifies the molecule responsible for the odor as R-delta-decalactone. A predator associating the odor with a painful encounter may be more likely to avoid a repeat experience.
The display of quills also provides a visual warning. The defensive position with the back to the attacker, tail ready to swat, displays the rosette, a striking mass of black-tipped white quills. The quills also have a fluorescent quality which makes them appear brighter and whiter in low light, when porcupines are most active and likely to encounter a predator. Other specialized quills in the rosette help wick and disseminate the odor-producing molecules.
Sound is a third signal. When threatened a porcupine may also slap its tail against the ground and chatter and clack its teeth.
Feeding Ecology:[]
The inner bark (phloem and cambium layers) of spruce, birch and hemlock and spruce needles are the major winter foods for porcupine living in Alaska. In the spring and summer, buds and young green leaves of birch, aspen, cottonwood and willow are eaten until the tannin levels build too high for the porcupine to tolerate. Because they are vegetarians and most vegetable matter is very low in sodium, porcupines need additional sodium in the blood to balance cell potassium levels. As a result, porcupines seek out salt sources such as natural licks, glue which bonds plywood together, human perspiration on tools, road salt, and some paints. Porcupines also feed on shed antlers and the bones of dead animals to obtain sodium and calcium. The salt drive is primarily in the spring when porcupines are sodium deficient.
Studies have shown that porcupines have sophisticated taste and dietary preferences. They will seek out and identify the most nutritious foods available at different times of the year and learn and remember these. Because they tend to be somewhat sodium deficient, they avoid or minimize the intake of acidic foods that require more sodium to metabolize. It’s often possible to see small chewed patches on trees where a porcupine has sampled the cambium and moved on.
Range & Habitat:[]
Porcupines are found throughout most of the forested areas of the state. They are not found on Prince of Wales Island in southern Southeast Alaska and the neighboring islands to the west. Evidence suggests they never colonized these islands after the ice age."
Porcupine Vocalizations (Sounds):[]
Listen to the sound of a porcupine at this link.
Porcupine vocalizations (sound/audio) from ADF&G website
Additional Resources:[]
North American Porcupine - Wildlife Notebook Series[]
Alaska Fish & Wildlife News Article: "Porcupine Research - How Tough Critters Survive Alaska Winters"[]
Sounds Wild Episodes:[]
Baby Porcupines[]
"In the lush greenery of an Alaska forest in spring, a mother porcupine is nursing her baby. The baby porcupine, called a porcupette, is just about a foot long and weighs a little more than a pound. He was born last week, and he's fully capable of following his mother around the forest as she forages on the lush green vegetation. He's able to eat a little as well. It'll be a few weeks before he'll be able to climb trees, and he'll continue nursing through the summer."
Sounds Wild Episode: Baby Porcupines
Mother porcupine nursing baby porcupine, called a porcupette from ADF&G website
Porcupine's Antibiotic Quills[]
"A few years ago my friends' dog got nailed by a porcupine. We wrapped her in a blanket and pulled a dozen quills out of her mouth and muzzle, but we missed one in the roof of her mouth. We discovered it a few weeks later when it came out by itself... on the other side. The quill migrated all the way through her muzzle and emerged point first.
Porcupine quills have microscopic barbs that do more than make them stick in the skin of an attacker; they cause the quill to work itself deeper into the victim. Porcupine researcher Uldis Roze noted similar experiences with migrating quills, including one that worked its way through his arm. Roze was astonished - not by the quill's action, but by what didn't happen. There was no infection. Curious, he investigated, and discovered that quills possess antibiotic properties.
Porcupine quills are coated with fatty acids that give the quills a greasy feel.
Extracts of quill fatty acids strongly inhibited the growth of six bacterial strains.
Roze suggests that porcupines benefit from antibiotic properties because they commonly quill themselves. Although porcupines are good climbers, they seek precarious places because they favor the leaves and buds at the ends of branches and the tops of trees. Roze examined 37 porcupine skeletons and found that one-third had suffered fractures from falls, and he commonly saw falling-related injuries in porcupines he studied. Roze suggests that quill antibiotics may limit self-injury suffered in such falls."
Porcupine Foods[]
Porcupines Mate[]
"A big porcupine waddles along the shoulder of the highway on a September evening, and fortunately a passing driver gives him a wide berth as she drives by. It's the fall mating season for porcupines, and males like this are on the move, looking for receptive females. People see porcupines more often in the fall because a male may expand his home range (of six to 12 acres) as much as five times in mating season. A female is in estrus just once a year, for about 12 hours. That's a narrow window, but males find them using their sense of smell. Females signal with a scent on their bodies and in their urine, and males track them down. If more than one male is interested in the same female, they will fight for the opportunity to mate.
Porcupines have an extremely long pregnancy, about seven months, the longest of any rodent. Moms give birth to just a single baby in the spring, called a porcupette. The quills are not a problem for the mother at birth as the porcupette is encased in a little sack known as a caul. The porcupette's quills are also soft and harden within an hour. The porcupette stays with its mother throughout its first summer, wandering off in the fall by the time she's ready to mate again."
Porcupine In Winter[]
Porcupine Sounds Wild Episode: Porcupine In Winter from ADF&G website
Porcupines Observed At Brooks Camp:[]
Date Unknown (March 13, 2024 or Prior):[]
KNP&P's March 13, 2024 08:10 AKDT "X"/"Twitter" post:
"Fun facts!
Did you know porcupines are good swimmers? Their quills are hollow making them act as a natural flotation aid.
Porcupines are the second largest rodent in North America, beavers being the largest, and adults can weigh up to 25 pounds!
Photo courtesy of Maurice Whalen"
Date Unknown (September 28, 2024 or Prior):[]
Cam Viewer & Park Visitor, Melissa Freels (aka MelissainOR), captured this photograph of a porcupine at Brooks Camp on September 28, 2024 or prior (p 09/28/24 08:25 #3).:
Please request Melissa Freels' permission PRIOR to using her photographs!
Between July 28, 2023 - August 4, 2023:[]
Cam viewer and park visitor, BetsyBear, observed two porcupines during the July 28, 2023 - August 4, 2023 trip to Brooks Camp. BetsyBear shared this information about her porcupine observations.:
"Not a bear, but ends up in many bear cub paws and also lives at Brooks Falls. When I posted the lynx photo from this year's trip to Brooks Falls, I mentioned I had also gotten to see two porcupines. Can't remember who wanted to see those pictures too, but finally getting to them on my camera. I saw one that appears to live under the NPS Visitor Center where you take bear class on arrival. And another waddled past me while I was relaxing during the day at Lake Brooks and ate leaves with its adorable little claw paw. I had to google all about porcupines when I got home since I realized I knew nothing about them (and missed the Ranger talk on them because I got confused on the days). Apparently their front incisor teeth are orange to red due to iron content."
BetsyBear also shared these two photographs of the porcupines she observed during her trip. Porcupine photograph by BetsyBear showing orange to red incisors (p 08/13/23 22:12). Porcupine at Lake Brooks (p 08/13/23 22:13).:
Please request BetsyBear's permission PRIOR to using her photographs!
2015 or Prior, Valley of 10,000 Smokes Road:[]
KNP&P video of a porcupine on the Valley of Ten Thousands Smokes Road. This video was taken by a handheld camera. At around 1:45 the porcupine definitely flinches, probably because it had not seen the camera/operator until just then. Porcupines have very poor eyesight. Earlier in the video, at 0:55 its quills stand up, indicating that it had sensed that something was nearby, likely through its excellent sense of smell.:
Porcupine on the Valley of Ten Thousand Smokes Road
KNP&P video
Porcupines Observed On Explore.org Live Cams:[]
2024 Season:[]
June 22, 2024:[]
Porcupines are apparently good swimmers! Who knew? Well, KNP&P's social media tried to educate us on this very fact on March 13, 2024 at 08:10 AKDT in their "X"/"Twitter" post. Thanks to our extremely talented Explore.org camera operators, Bearcam viewers got to witness the swimming skills of a porcupine resident at Brooks Camp on June 22, 2024.
LunaCre created these gifs of the porcupine observed on the Kat's River View live cam. Porcupine stopped by the lower river (#10). Porcupine poses for us (#11). Porcupine swims with some ducks (#12). Porcupine gives a really good shake before leaving (#13) (p 06/23/24 01:44).:
twelve22 captured this video of the porcupine on June 22, 2024 (longer version):
Porcupine Goes for a Swim - June 22, 2024 (explore.org)
video by twelve22
Kaz Bear22 captured this video of the porcupine taking a swim (shorter version):
Porcupine has a swim in Naknek Lake, Katmai, Alaska. 22 June 2024 (explore.org)
video by Kaz Bear22
JMcNature created this video of the porcupine observed on June 22, 2024:
Katmai Brown Bears ▪︎ Cute Porcupine Walks & Swims on KRV ▪︎ 6-22-24 ▪︎ Explore.org
video by JMcNature
September 3, 2024:[]
32 Chunk was making a living pulling the late night shift while a pair of snowshoe hare appeared to play and a porcupine evaded full cam view for a while...but the porcupine was no match for the cam op on duty pulling the late night shift with 32. FloppyLeftEar created this gif of the porcupine observed (p 22:46). Raptor747 created a series of gifs to document the exciting late night shift at the river activities (32 Chunk Late Shift Fishing, Pair of Snowshoe Hare, Porcupine in Full Cam View, and 32 Chunk departing for the night) (p 09/04/24 00:04).:
Created 11/19/2024 LTC