Campus Biodiversity: Raccoons

With their ringed tails and black “masks,” raccoons (Procyon lotor) are easy to recognize. These curious and smart mammals are native to North America. Due to their extreme adaptability and opportunistic natures, they are also part of the urban wildlife on the UT campus.

The word “raccoon” has been identified as a reflex of a Proto-Algonquian root – ahrah-koon-em - which translates into “one who rubs, scrubs and scratches with his hands.” In fact, this “scrubbing” behavior figures into the animal’s name in other languages: Waschbär (wash bear) in German, huànxióng 浣熊 (wash bear) in Chinese, orsetto lavatore (little bear washing) in Italian, and araiguma アライグマ (washing-bear) in Japanese.

Its scientific name is Procyon lotor. The genus Procyon can be translated into “dog like” or “before the dog.” Lotor is neo-Latin for “washer.”

With about 20 sub species of raccoons, they are one of the most variably sized mammals, ranging from 10 to 60 pounds, but their weight usually falls between 10 to 30 pounds. To survive winter in harsher climates, raccoons gain quite a bit of weight, sometimes doubling their size.

They have short legs which means they aren’t terribly fast runners, but there are plenty of other attributes that give them advantages. They are strong swimmers and able to stay in water for hours. They can climb down a tree headfirst as they are able to rotate their feet to point backwards. They also have a dual cooling system, panting and sweating, which allows them to regulate their temperature well.

One of their most distinctive features is the swatch of black fur around their eyes. This fur may help reduce glare and enhance night vision as these creatures are primarily nocturnal. In folklore, this swatch of black hair has made the raccoon appear as a bandit, enhancing its reputation for mischief.

They also have paws made very sensitive by their vibrissae on the tips of the digits. Their sense of touch is so important, that about two thirds of the area that handles sensory perception in their cerebral cortex is devoted to interpreting tactile impulses. This is larger than any other studied mammal.

For their other senses, it’s believed raccoons are unable to distinguish color very well and have poor long-distance vision. However, their sense of smell makes up for this as it helps the animal navigate darkness as well as understand territorial markings of other raccoons. They also can hear very well, with an ability to perceive tones up to 50 - 85 kHz. For comparison, the general upper range of hearing for younger humans is around 20 kHz.

Raccoons are intelligent which makes them perfect residents of the campus. Their learning speed is comparable to Rhesus macaques. They can recall solutions to tasks for at least three years. In different studies, raccoons could open complex locks after a few tries, and could recall how to open them even if the locks had been rearranged.

For a long time, it was believed raccoons were solitary, but this is not entirely true. Unrelated males will form groups of around four to protect themselves against invaders and maintain the territory against foreign males. Females will share a common area to occasionally meet, feed or rest. Outside of this, however, they are generally solitary creatures.

Raccoons are generally nocturnal but will roam during daylight to find food. This is particularly true of nursing females. As omnivores, they will eat a wide variety of foods including insects, fish, nuts, fruit, amphibians, bird eggs, and of course human garbage and pet food left outdoors. Occasionally, they will eat birds and other smaller mammals, but not often as they are harder to catch.

Then there is the washing behavior so many associate with raccoons. The act of a raccoon carrying food to water to wash it before eating has not been observed in the wild, only in captivity. In the wild, they dabble underwater for food near the shoreline, will retrieve something, then douse the item to remove unwanted parts.

Mating happens shortly before spring and males will wander from their homes to find females. Foreplay is involved and copulation can last over an hour. This is repeated several nights. The female will have a gestation period of 63 to 65 days, and give birth to 2 to 5 young, called kits or cubs, who are blind and deaf at birth. Males do not assist in raising the young.

After about 16 weeks, the kits are weaned. Many females stick around the home range, but males move away, the thought being this is an instinctual behavior to prevent inbreeding. 

he lifespan of a raccoon in captivity can be quite long, sometimes more than 20 years. But in the wild, it is quite short, 1.8 years to 3 years. Hunting, traffic, and distemper can have a significant impact on the population.

While tree hollows and rock crevices serve just fine as homes in the wild, raccoons have adapted to urban life and have no problem living in attics, chimneys, and crawl spaces in houses and buildings. However, this can cause significant damage to property and thus they are often considered nuisances. Additionally, raccoons can carry rabies. Affected animals will look ill, have impaired mobility, make abnormal vocalizations, and can become aggressive. It’s important to note that a raccoon roaming during the day is not necessarily a sign the animal has rabies. Nursing females will commonly roam for food during the day.

Not surprisingly, the raccoon has a role in many mythologies of indigenous peoples of the Americas. The animal is considered a trickster by the Tuscarora, and the Aztecs believed females had supernatural abilities in their role as mothers. The image of a raccoon appears in Native American petroglyphs, figurines, and carvings.

UT RACCOONS

There are quite a few raccoons at UT, according to Carin Peterson from Environmental Health and Safety (EHS) on campus, and it’s likely that we even have an overpopulation, although there are still studies that need to be done on this. A Google search about UT raccoons will reveal posts and photos about them raiding campus trashcans or stealing food from "Domino," the iconic black and white cat that lives near FAC. “They are too smart for their own good and it gets them into trouble,” Carin says, noting raccoons will take advantage of any way into a building. “Of course, they would much rather live in an air conditioned or heated building than outside.”

Waller Creek, the stream that flows though campus and ends at Lady Bird Lake, is a raccoon “highway,” according to Carin. They also use storm sewer systems to get around.

UT raccoons are acclimated to people and so are not that frightened. Carin notes that seeing one in the day hours is mostly due to construction disturbances, rather than the animal being sick. If the animal is acting ill, she says, it’s probably due to distemper or an injury, rather than rabies. Animal Make Safe (https://ehs.utexas.edu/programs/animalmakesafe/) or Austin Animal Services should be called. https://www.traviscountytx.gov/health-human-services/animal-control

“As cute as they are,” Carin says, “they are still wild animals, can be aggressive, and considered a high-risk rabies species in Texas. They should never be touch or fed, especially by hand.”