Do Porcupines See Well?
The North American Porcupine is one of the species that belong to the New World porcupines. These are porcupines that are located in North and South America. This porcupine is the largest among its species and can be found in Mexico, the United States, and Canada.
It is a tree-dwelling rodent covered in spikes and has a well-developed system of senses.
Except for its sense of sight!
The North American porcupine’s poor eyesight is one of its weaknesses. Often, it is unable to see when a threat is looming. It can be preyed upon by animals that are able to take advantage of this fact such as fishers -a type of weasel. Fishers are aware of the porcupine’s weakness and that its underbelly is unprotected from quills. This is why porcupines are a prime target.
It is also one of the reasons to blame for its frequent fall from trees. Animal experts found out that porcupines tend to fall from trees quite often since they are slow-moving and short-sighted animals. This happens despite the porcupine being relatively well-adapted for climbing, using its thick claws.
Baby porcupines are born with their eyes open. They are able to sense their mother and follow her around, but the babies don’t see any better than their mothers. Despite its bad eyesight, is still able to climb small trees within the day or bigger trees after a few weeks, which is quite impressive for a newborn!
The baby porcupine’s poor eyesight is also one of the reasons why the mothers don’t bring along their babies when they go climb trees to feed. Baby porcupines are instead hidden on the ground, while the mother goes to take care of business.
How Do Porcupines Compensate For Their Bad Eyesight?
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While porcupines have bad eyesight, they have learned to adapt to their environment by using their other senses which are quite well-developed. Their sense of hearing, sense of smell, and sense and touch are all impeccable. These are called the “nighttime senses” and they are the right skills for a nocturnal animal that lives in the wild.
Porcupines Have Extraordinary Hearing
The sense of hearing of a North American porcupine is highly developed. They are able to hear sounds that are not even audible to humans. Porcupines can easily hear even very quiet sounds, such as someone walking in the snow up to 30 feet away.
Having a good sense of hearing is highly useful for these poorly-seeing animals when trying to evade predators and dangers. Hearing something moving from far away will give them sufficient time to flee for safety.
The Porcupine‘s Phenomenal Sense of Smell
Porcupines’ sense of smell is highly sensitive, especially scents that would prove beneficial for them. Among other things, porcupines use their sense of smell for locating possible foraging areas.
Porcupines are great at picking out food smells from afar, and their noses can easily lead them in the right direction, especially if they’re hungry. On the other hand, porcupines are dissuaded by the scents associated with their predators.
Adult porcupines are known to mark the trees in important areas by urinating on the base. They can then much easier find their way back to the same location by using their sense of smell. This is helpful at night time when it is difficult for them to search for their feeding ground without light.
Even juvenile porcupines depend highly on their sense of smell for food. Even juvenile porcupines are able to tell which trees are suitable for food by smelling the urine left by other porcupines on the base of the tree. They are able to identify a good “food tree” even when the location is new and unfamiliar, and they can even detect very faint smells.
In one conservation facility, juvenile porcupines were documented to locate the tree for feeding despite the rain that heavily poured in the area a week ago, which probably had washed away most of the scent that was left by another porcupine. Most of the trees that were marked with urine scents were distant from each other.
The porcupine’s sense of smell is extremely important to the porcupine for navigating the forest and finding its feeding areas, and it strongly makes up for the rodent’s underwhelming eyesight.
Porcupines Have Spectacular Sense of Touch
In humans, the blind use their hands to make sense of the world. Poorly seeing porcupines, on the other hand, are reliant on their sense of touch in a different way and for a different reason.
Their paws are not used to feel and guide them to their intended location. Their sense of touch is not meant for feeling the textures of what is around them. Instead, their special whiskers or guard hairs called vibrissae are meant for protection.
Porcupines have very sensitive whiskers on their face. These whiskers help the porcupine sense vibrations in the air, ground, and general surroundings, by being extremely sensitive to movement. The quills that the porcupine has all over its body help sense movement in a very similar way.
The porcupine’s whiskers and quills help warn the animal about the slightest movement in its environment. In tight spaces of the tree branches, this ability acts like a “spidey sense”, alerting the porcupine of the presence of others. This enables the porcupine to prepare and take action against possible predators lurking in the dark.
Can Porcupines See In The Dark?
The North American porcupine has some degree of night vision, but they don’t see as well in the dark as cats and other known nighttime hunters.
The reason for this is, that the tissue (called tapetum ludicum) inside of the porcupine’s eye, behind the retina, is responsible for seeing in low-light conditions at night. In the porcupine, however, it is relatively poorly developed, compared to other nocturnal animals.
Porcupines can see in the dark but not as well as other animals like cats, foxes, or badgers. This is why they are dependent on their other senses to navigate their environment at night. They use their sense of smell, sense of hearing, and sense of touch so they could find their way around the forest.
It is believed that one of the reasons they are foraging on top of trees is the presence of light. Canopies of tall trees provide better light conditions than the undergrowths of forests and are suited for foraging for animals with poor vision much more than shrubs.
Can Porcupines See Colors?
Like other animals in the rodent family, porcupines are considered to have “dichromatic vision” or color blindness. This is the inability to see certain types of colors. Dichromatism is the inability to see two out of the three primary colors: Blue, red, and green.
In porcupines, they seem to be unable to differentiate the colors of green and red. They are also unable to identify the shades of these colors-whether darker or lighter. This condition called deuteranopia makes it difficult to perceive not just the colors red and green but also their shades.
These three colors are seen differently, mostly an overlap of the real colors. The color red may be perceived as yellow-brown and green as yellow.
However, porcupines compensate by showing some ability to see ultraviolet light. Some studies suggest that they are able to not just smell but also see the urine marks of other animals. They are also able to determine how old these marks are. The latest markings are seen as brighter under UV vision compared to the older markings.
What Color Are Porcupines’ Eyes?
The porcupine’s eyes are dark brown in color. Generally, there isn’t a lot of variation in the porcupine’s eye color, but there are cases of albinism in porcupines, where all quills are completely white and the eyes are red.
Albinism is a condition where the skin, hair, and eyes have no melanin, which is the color pigment that generally gives people and animals their skin, hair, and eye colors. Without melanin, you can actually see the blood cells inside of the eye directly, which is why albino porcupines have red eyes.
Other than the (very) rare cases of albino porcupines out there, they all have dark brown eyes.
Do Porcupines’ Eyes Glow At Night?
Animals’ eyes, especially nocturnal animals, tend to glow at night. The glowing color of their eyes differs depending on the species. The colors of eye glow are red, yellow, green, white, and orange.
The porcupine’s eyes glow with a deep red color. Compared to other animals, the porcupine’s glowing eyes are not as striking as others because the tissue behind its retina called tapetum ludicum which is responsible for night vision is inadequately developed.
For further details, see Roze, U. (2012). Form and Function of Porcupines. In Porcupines: The animal answer guide. essay, Johns Hopkins University Press.