How closely related lemurs are to raccoons

This article describes the species, for the genus see article raccoons.

The racoon (Procyon lotor), also as North American raccoon or ancient as Dandruff is a medium-sized mammal native to North America. Since the middle of the 20th century it has also been represented as a neozoon on the European mainland, the Caucasus and Japan, after it escaped from enclosures or was released there. Raccoons are predominantly nocturnal predators and prefer to live in deciduous and mixed forests that are rich in water. Due to their adaptability, they are increasingly living in mountain forests, salt marshes and urban areas.

With a body length between 41 and 71 centimeters and a weight between 3.6 and 9.0 kilograms, the raccoon is the largest member of the small bear family. Typical for the raccoon are the pronounced haptic perception of the front paws and the black face mask. Also to be emphasized is the good memory of the animals, which in experiments were able to remember the solution of a previously set task even after three years. Raccoons are omnivores and their diet is roughly 40 percent plant-based, 33 percent mollusc and 27 percent vertebrate. Raccoons kept in captivity often submerge their food under water, which has been interpreted as "washing", but is very likely an idle act to imitate foraging for food on river or lake banks, where he, groping under stones and other hiding places, for crabs or other food animals seeks.

While the raccoon was once thought of as a loner, there is now evidence that it displays gender-specific social behavior. Related ferries (females) often share a common area; Unrelated males, on the other hand, live together in loose, small groups of up to four animals. This enables them to assert themselves better against strange males and against potential attackers during the mating season. The size of the home ranges varies between 0.03 square kilometers for females in cities and 49.5 square kilometers for males in the prairie. After a gestation period of around 65 days, the female gives birth to two to five cubs in spring, depending on the local situation. The puppies are then raised alone by their mother until they gradually separate in autumn. Although captive raccoons can live to be over 20 years old, their life expectancy in the wild is only 1.8 to 3.1 years. Hunting and road accidents are the two leading causes of death in many areas.

Taxonomy

Naming

The English word for the raccoon, raccoon (occasionally also racoon), goes back to a word in the Algonquin language used by Chief Powhatan and his daughter Pocahontas ahrah-koon-em - other spellings exist - was pronounced and means something like "he who rubs, scrubs and scratches with his hands" means. The Spanish word introduced by Spanish colonialists is derived from the same mapache from the Aztec word mapachitli from what can be translated as "who takes everything into his own hands". In addition to German, a word is also used in many other languages ​​to designate the raccoon, which is made up of a term for the typical “washing” of food in captivity and the respective word for bear composed, for example orsetto lavatore in Italian and araiguma (洗 熊) in Japanese. The colloquial English abbreviation coon is in words like coonskin for fur clothes and old coon used as a self-designation by trappers.[1][2]

In the first decades after the discovery of the raccoon by the members of the expedition of Christopher Columbus, who was the first person to write a written record of the animal species, taxonomists assumed a relationship to many other animal species, including dogs, cats, badgers and above all the bear. Carl von Linné, the father of modern taxonomy, also assigned raccoons to the genusUrsus to, first as Ursus cauda elongata ("Long-tailed bear") in the second edition of his Systema Naturae, and finally as Ursus Lotor ("Raccoon") in the tenth edition. In 1780, the German naturalist Gottlieb Conrad Christian Storr assigned the raccoon its own genus with the name Procyon to, which translated can mean both “in front of the dog” and “dog-like”. Due to the raccoon's nocturnal lifestyle, Storr could also have chosen the star Prokyon to give the genus its name.[3][4][5]

evolution

Based on fossil finds in France and Germany, it is assumed that the first representatives of the small bear family lived in Europe about 25 mya (late Oligocene). Similar tooth and skull structures suggest that small bears and martens share a common ancestor, but molecular analysis suggests they are more closely related to bears. After crossing the Bering Strait at least six million years later, the center of the range of the species occurring at that time was probably in Central America. Coatis (Nasua and Nasuella) and raccoons (Procyon) possibly went from 5.2 to 6.0 mya from a species of the genus Paranasua emerged. This assumption, based on morphological fossil comparisons, contradicts a genetic analysis carried out in 2006, according to which raccoons are more closely related to cat frets.[6] In contrast to the other small bears, such as the crab raccoon (Procyon cancrivorus), raccoon ancestors left tropical and subtropical areas and moved north about 2.5 mya ago, as evidenced by the discovery of mid-Pliocene fossils found in the Great Plains.[7][8]

Subspecies

Five raccoon species that occur exclusively on small Central American and Caribbean islands were mostly viewed as separate species after their discovery. These are the Bahamas raccoon and the Guadeloupe raccoon, which are very similar, the Tres Marias raccoon, which is larger than average and is characterized by a conspicuously square skull, the Cozumel raccoon, which only has three to weighs four kilograms and has particularly small teeth, and the extinct Barbados raccoon. However, morphological and genetic studies carried out in 1999, 2003 and 2005 resulted in the fact that all of these so-called island raccoons with the exception of the Cozumel raccoon (Procyon pygmaeus), in the third edition of the zoological standard work Mammal Species of the World (2005) listed as subspecies of the (North American) raccoon.[9][10][11][12]

The four smallest subspecies, including for example Procyon lotor marinus, each with an average weight of 1.8 to 2.7 kilograms live along the south coast of Florida and the adjacent islands. Most of the other 15 subspecies differ only slightly from each other in terms of coat color, size, or other physical characteristics. The two most common subspecies are Procyon lotor lotor and Procyon lotor hirtus. Like the bigger one P.l. hirtus also points P.l. lotor a comparatively dark, long-haired coat. P.l. lotor occurs in all US states and Canadian provinces north of South Carolina and Tennessee. The adjacent distribution area of P.l. hirtus includes all US states and Canadian provinces north of Louisiana, Texas, and New Mexico.[13][14]

Features of the raccoon

anatomy

Underside of the front paw

Its body length is between 41 and 71 centimeters, not counting the 19.2 to 40.5 centimeters long bushy tail, which is usually not significantly longer than 25 centimeters. The shoulder height is between 22.8 and 30.4 centimeters. The body weight of adult raccoons differs between 1.8 and 13.6 kilograms, depending on the area of ​​distribution and the time of year, with common values ​​between 3.6 and 9.0 kilograms. The smallest individuals can be found on the south coast of Florida, the largest according to Bergmann's rule on the northern limit of the range. Male specimens are typically 15 to 20 percent heavier than females. At the beginning of winter, raccoons can weigh more than twice as much as in spring due to the eaten winter fat. The heaviest raccoon living in the wild weighed 28.4 kilograms, which is by far the highest weight of a small bear ever measured.[15][16][17][18]

The characteristic facial drawing of the raccoon with the black colored face mask around the eyes, which contrasts sharply with the surrounding white fur, is similar to that of the raccoon dog. The slightly rounded ears are also surrounded by white fur. It is assumed that raccoons can more quickly grasp the facial expression and posture of conspecifics due to the distinctive facial drawing in conjunction with the light-dark striped tail. The dark mask could also reduce glare and thereby improve night vision. On the rest of the body, the long and water-repellent upper fur is colored in various gray and, to a lesser extent, brown tones. Raccoons with very dark colored fur are mainly represented in the German population, as there were individual animals with such fur patterns in the founding population.[19] The dense undercoat, which makes up almost 90 percent of the total number of hair, protects the animals from the cold and consists of 2.0 to 3.0 centimeters long hair.[20][21][22][23]

Raccoons, generally classified as sole walkers, can stand on their hind legs and examine objects with their front paws. Because raccoons have short legs in relation to their stocky torso, they are unable to run fast or jump far. Their top speed over short distances is 16 to 24 kilometers per hour.[24] Raccoons can swim at an average speed of 3 miles per hour and can stay in the water for several hours. To climb down a tree head first, an unusual skill for a mammal of this size, raccoons twist their hind paws until they point backwards. Raccoons can both sweat and pant to regulate their body heat. Your dentition with the tooth formula 3142/3142 consists of 40 teeth, which are adapted to your way of life as an omnivore. The chewing surface of the molars is not as wide as that of pure herbivores, nor are the incisors as sharp and pointed as that of pure carnivores. The penis bone of the males is about ten centimeters long and strongly curved at the front end. Seven of the 13 known vocal expressions are used in communication between mother and young animals, including the birdlike chirping of newborns.[25][26][27]

Sensory perception

The most important sense for the raccoon is the sense of touch. The "hypersensitive"[28] For their protection, the front paws are surrounded by a thin horny layer that softens under water. The five free-standing fingers are also unusual for a predator, although the mobility of the front paws cannot be compared to that of the hands of primates due to the non-opposable thumb. Almost two thirds of the area of ​​the cerebral cortex responsible for sensory perception specializes in the interpretation of tactile stimuli, more than any other animal species examined. With the vibrissae over the sharp, non-retractable claws, raccoons can recognize objects even before they are touched. It is unknown why tactile perception is not negatively affected when a raccoon stands in water that is less than ten degrees Celsius for hours.[29][30][31][32]

It is believed that raccoons are color-blind or at least have difficulty distinguishing colors, with green light being particularly well perceived. Although the tapetum lucidum behind the retina, which acts as a residual light intensifier, allows them to see well in twilight and the visual acuity range of eleven diopters is comparable to that of humans, visual perception is of secondary importance for raccoons. In addition to orientation in the dark, the sense of smell is especially important when communicating with fellow dogs. Urine, feces and glandular secretions, which are mostly distributed with the anal gland, are used as scent marks. With their hearing, the hearing limit of which is 50 to 85 kHz, raccoons are able to perceive very quiet noises, such as those caused by earthworms buried in the ground.[33][34][35]

Mental faculties

Of the few studies that have been done on the raccoon's mental abilities, most are based on his tactile perception. In an experiment by behavioral scientist H. B. Davis in 1908, the raccoons investigated succeeded in opening eleven of 13 complex locks in less than ten attempts and then adjusting their procedure after the locks were rearranged or turned upside down. Davis concluded that they understood the abstract principle behind the locking mechanisms and that their learning pace matched that of rhesus monkeys.[36] Investigations in 1963, 1973, 1975 and 1992 tested the memory of raccoons and found that even after three years they could still remember the solution to a previously set task. In 1992, for example, B. Pohl showed that three years after the brief initial training phase, raccoons could immediately differentiate between the same and different symbols. Stanislas Dehaene reports in his book The sense of numbersthat raccoons can distinguish containers that contain two or four grapes from those that contain three.[37][38]

Way of life

Social behavior

Raccoons eating together

Two studies conducted in the 1990s by the behavioral researchers Stanley D. Gehre and Ulf Hohmann showed that, contrary to earlier assumptions, raccoons do not normally live solitary, but rather show gender-specific social behavior.[39] Females related to one another live in a so-called fission-fusion society, that means they share a grazing area and occasionally meet at common feeding places or sleeping places. Unrelated males live in loose Male coalitions together in order to be able to assert themselves against strange males during the mating season or other potential attackers. Such a group usually consists of no more than four individuals. Because adult males can show aggressive behavior towards cubs that are not related to them, mothers avoid other raccoons until their cubs are big enough to be able to defend themselves. Because of these three different ways of life, the social structure of the raccoon is also called by Hohmann Three-class society designated.[40] Samuel I. Zeveloff, professor of zoology at Weber State University and author of the monograph Raccoons: A Natural History (Raccoons: A Natural History) is more cautious in his presentation of the state of research and points out that at least the females lived solitary most of the time and, with reference to a study carried out by Erik K. Fritzell in North Dakota, also males in areas with low population densities.[41][42][43]

If there is enough food, the raccoons' areas of activity can overlap significantly without causing any disputes. Raccoons meet at assembly points or leave messages there in the form of scented tags to exchange information about rich feeding places or well-protected sleeping places.[44] Raccoons also meet to eat, sleep and play together.

nutrition

Raccoon foraging on the lake shore

Raccoons are omnivores, and their diet is roughly 40 percent invertebrates, 33 percent plant-based, and 27 percent vertebrates.[45] According to zoologist Samuel I. Zeveloff, the raccoon is one of the "most omnivorous animals in the world".[46] While raccoons mainly eat insects, worms and other animals that are already available in spring,[47] prefer high-calorie, plant-based foods such as fruit and nuts in autumn to get enough winter fat.[48] As for vertebrates, fish and amphibians are the most common prey.[49] Contrary to popular belief, raccoons only eat birds and small mammals sporadically, as the comparatively laborious hunt to capture these animals is not worthwhile for them.[49] With large food choices, raccoons can develop strong individual preferences for certain foods.[50] In contrast, in winter they can hardly find any food and even have to fast if the frost persists.

Raccoons often “wash” their food in captivity.

"Washing" the food

Raccoons carefully scan food and other objects with their front paws to get an idea of ​​them and remove unwanted parts. If the protective cornea is softened under water, its sensitivity increases.[51][52] While raccoons never take food found on land in the wild to a watering hole in order to "wash" it there before consumption,[53][54] this behavior can often be observed in captive animals.[55] The French naturalist Georges-Louis Leclerc de Buffon (1707–1788) still believed that raccoons did not have sufficient salivary glands to moisten the food,[56] which is definitely wrong.[57][58][59][60] Raccoons kept in captivity often “wash” their food when a watering hole with a bottom similar to a river bed is no more than three feet away.[61] It is widely believed that “washing” food is an idle act designed to mimic bank foraging for small creatures.[62][63][64] The observation that aquatic foods are “washed” more frequently supports this theory.[61] Cleaning contaminated food, on the other hand, does not seem to play a role in most cases.[61] On the other hand, it is disputed whether even wild raccoons tend to soften very dry food under water on occasion.[65][66]

Habitat

Apart from urbanized animals, mixed and deciduous forests rich in water with a high proportion of oak are the preferred habitat of raccoons. Here they find enough food and shelter. In case of danger, they take refuge in a tree, so they avoid open terrain. Raccoons are good swimmers and prefer to live near rivers or other bodies of water, where they find most of their animal feed. In America, due to its adaptability, raccoons are increasingly able to colonize habitats that are considered unsuitable for them, such as steppes or cold areas further north.

Sleeping places

Raccoons are good climbers.

Raccoons are crepuscular and nocturnal animals, which is the main reason they are rarely seen. They are skilled climbers and prefer to sleep in the hollows of old oak trees during the day. If a raccoon is out of range of one of his preferred main sleeping areas, he can alternatively move to old stone quarries, in dense undergrowth or in badger burrows. In the northern areas of its range, the raccoon hibernates during which it greatly reduces its activities.

Reproduction

Raccoon puppy (around eight weeks old)

So that the rearing of the pups does not coincide with the beginning of next winter, raccoons usually mate in February. If a female does not conceive or loses her young prematurely, she will sometimes be ready to conceive again in May or June. During the mating season, the males roam restlessly in their home areas and woo the females who come together at some assembly points, whose three to four-day conception periods coincide. The subsequent pairing extends over several nights, during which intensive foreplay, the actual act and a subsequent break alternate. Most females can only be mated by one male.

In order to compensate for a high mortality rate, for example caused by hunting, the proportion of pregnant females rises sharply. While the total population remains almost stable as a result, the average age is falling rapidly. In this respect, it is almost always ineffective to try to drive raccoons out of an area that is a favorable habitat for them through increased hunting. Even if this were to succeed as an exception, other raccoons would soon follow them into the territories that would become free.

Development of the young

After about 65 days of gestation, the female, who lives alone again after mating, gives birth to an average of 2.5 to 3.5 young in spring. The pups are blind at birth and covered with a yellowish fluff. The birth weight of the ten centimeter tall puppies is 65 to 75 grams. During the first month of life, the puppies do not consume solid food, but are suckled exclusively by their mother. They open their eyes for the first time after two to three weeks. At the age of six to nine weeks, the boys, which at this point weigh about one kilogram, leave the litter box for the first time, but are nursed for a further one to two months with decreasing intensity. Gradual separation from the mother takes place in autumn. While the females reach sexual maturity before the start of the next main mating season, this is only the case with some of the males. While many female offspring stay close to their mother for life, the young males seek out more distant territory, which is to be understood as instinctive behavior to avoid inbreeding.

Life expectancy

Like captive animals, wild raccoons can live to be 16 years and older, but most live only a few years.[67] It is not uncommon for only half of the pups born in a year to survive by their first birthday.[68] Then the annual death rate drops to 10 to 30 percent.[69] One of the most common natural causes of death for young raccoons, apart from the death of their mother in the first few weeks of life, is starvation during the first winter, especially when it is particularly cold and long.[70] The leading natural cause of death in North America is distemper, a common epidemic disease that can kill many raccoons in an area.[71] In areas with high traffic and where raccoons are hunted extensively, these two causes of death can account for up to 90 percent of all adult raccoon deaths.[72]Natural predators such as bobcats, coyotes and other predators usually do not play a crucial role as a cause of death, especially since larger predators have been exterminated by humans in many areas.[73] All in all, the life expectancy of wild raccoons is therefore only 1.8 to 3.1 years, depending on local conditions in terms of traffic volume, hunting pressure and extreme weather conditions.[74]

Distribution area

Spread in America

Worldwide distribution of the raccoon
♦ original home
♦ introduced

The original range of the raccoon stretches from Panama to Mexico and almost all of the USA to southern Canada. The only exceptions are desert areas and the high mountains of the Rocky Mountains.

Distribution of raccoons in Germany: Raccoons killed while hunting or found dead by hunters in the hunting years 2000/01, 01/02 and 02/03 in the German districts.

Distribution in Europe

All raccoons found in Europe can be traced back to animals that escaped or were abandoned from fur farms and enclosures in the 20th century. As such captive refugees, they can be assigned to the group of neozoa, although they are now counted among the native animal species in Germany. Today there are stable raccoon populations in large parts of Germany and in areas of neighboring countries. Further occurrences exist in the south of Belarus, the Caucasus and in the north of France, where some specimens were released by American soldiers near Laon in 1966.

The most important event for the spread of raccoons in Europe was the release of two pairs of raccoons on April 12, 1934 on the Hessian Edersee[75] . The four raccoons were released by the forester Wilhelm Freiherr Sittich von Berlepsch at the request of the owner, the poultry farmer Rolf Haag, even before he received the approval of the Prussian State Hunting Office two weeks later in order to "enrich the local fauna". Although there had been a few attempts to settle there before, only this one was successful. The area around the Edersee represented an almost optimal habitat for the released raccoons, so that the further spreading from this center could take place quickly and permanently. In 1956 the population in Germany was estimated at 285 animals, in 1970 at around 20,000 animals and in 2005 at a low to medium six-digit number. Although this founder effect created a genetic bottleneck, it does not appear to have had any negative effects on the health of the raccoon population.

The outbreak of about two dozen raccoons after a bomb hit a raccoon enclosure in Wolfshagen (now part of Altlandsberg) near Strausberg in Brandenburg in 1945 led to a further distribution area. The resulting population can be distinguished genetically and parasitologically from the Central German population to this day. While over 70 percent of the raccoons in the Central German population are infected with the raccoon roundworm, no raccoon from the Brandenburg area has been diagnosed with roundworm infection. An infection rate of 39 percent was measured in Saxony-Anhalt, which is why this area seems to play an important role as the merging area of ​​the two large populations.

In the 2010/2011 hunting season, 67,700 raccoons were killed in Germany. In the 1990s this number was only 400 animals.[76]

The raccoon as a neozoon

The raccoon is one of the most successful neozoa on the European continent, as it has spread over large parts of Germany within a few decades. Many hunters and foresters, as well as some nature conservationists, are of the opinion that the uncontrolled spread has negative effects on the ecosystem of German forests. The main argument is that raccoons displace native predators and protected bird species. The zoologists Ulf Hohmann and Frank-Uwe Michler[77][78] contradict this view. Hohmann argues that the lack of natural enemies in Europe alone does not justify extensive hunting, as these did not play a role as a major cause of death in the North American range.[79] In addition, the population densities reported in the press are sometimes more than ten times higher than those actually measured.[80]

Michler points out that there is no evidence that a high population density has negative effects on the biodiversity of an area. Therefore, it is “pure speculation” and devoid of “any seriousness” if, without prior scientific investigation, a causal connection between raccoon occurrences and the population decline of another species is established in an area. For this reason, the control of raccoons according to the Bern Biodiversity Convention is rejected by him, as this presupposes particularly negative effects of a neozoon on an ecosystem. In contrast, a more consistent approach than usual would be required to protect local bird populations if necessary, which, however, requires a high level of personnel and financial expenditure.[19]

In addition, the hunters Hohmann and Michler point out animal protection violations in raccoon hunting.[81] In a press release of the Michler headed "Raccoon Project" to investigate raccoon occurrence in the Müritz National Park condemned the use of traps in areas with raccoon occurrences as "deliberate cruelty to animals", since there is no difference to the effect of forbidden leghold traps by picking up the bait with the front paws.[82]

Urbanized raccoons

Due to its adaptability, the raccoon has succeeded in using urban areas as living space. The first reports of raccoons living in urban areas date back to the 1920s in a suburb of Cincinnati, Ohio. Raccoons have been found in large numbers in North American metropolises such as Washington D.C., Chicago, and Toronto since the 1950s.[83] Since the 1960s, Kassel has been home to Europe's first and densest raccoon population in a large urban area with around 50 to 150 animals per square kilometer; a number comparable to those found in urban habitats in North America.[84][83] High population densities are also reported from other localities in northern Hesse and southern Lower Saxony. There are isolated sightings in many other cities like Berlin.[85]

The size of the action areas of urbanized raccoons is reduced to about 0.03 to 0.38 square kilometers for females and 0.08 to 0.79 square kilometers for males.[86] In small towns and suburbs, many raccoons sleep in the nearby forest after foraging in the settlement area.[87][83] Fruits and insects in gardens and leftovers in garbage are readily available sources of food.[88] There are also a large number of additional sleeping and throwing places such as tree hollows in old garden trees, garden sheds, garages, abandoned houses and attics. The number of raccoons sleeping in homes fluctuates from 15 percent in Washington D.C. (1991) up to 43 percent in Kassel (2003).[87]

Raccoon and human

Conflicts

Raccoon on the roof of a residential building in Albertshausen, Northern Hesse

The increasing number of raccoons in human settlement has led to very different reactions, ranging from total rejection to regular feeding of the animals.[89] Most authorities and some wildlife experts warn against feeding wild animals because it would make them more intrusive or dependent on humans as a source of food.[90] Other wildlife experts question this and give advice on feeding wild animals in their books.[91][92] A lack of fear of people is very likely not a sign of rabies, but an adaptation of the behavior of the animals that have lived in the city for many generations.[93]

While emptied garbage cans and harvested fruit trees are mostly seen as a nuisance by house owners, repairing damage caused by raccoons when using attics as a sleeping place can cost several thousand euros.[94] However, catching or killing individual animals usually only solves problems with particularly wild or even aggressive specimens, as suitable sleeping places are either known to several raccoons or will soon be rediscovered.[95][96] Instead, preventive measures - like pruning branches - that prevent raccoons from getting into the building in the first place are much more effective and cheaper.[97][98]

Often it is not possible to drive raccoons permanently from an area that is a suitable habitat for them through intensive hunting, as they can increase their reproduction rate up to a certain limit or animals immigrate from the surrounding area to the free roaming areas. Young males also claim smaller grazing areas than older ones, which results in an increase in population density.[19] The cost of removing all raccoons from a larger area, even temporarily, usually exceeds the cost of the damage they cause many times over.[19]

Raccoons as vectors of disease

The increased contact between raccoons and humans results in problems with the transmission of diseases. In contrast to its American homeland, the raccoon in Europe has a very limited range of parasites. While raccoon rabies is a serious threat in America, it has only been proven sporadically in Europe. Only one raccoon parasite is currently considered to be a potentially dangerous pathogen for humans, namely the raccoon roundworm, which lives in the small intestine of the animals. The infection occurs through the oral ingestion of roundworm eggs in the raccoon droppings, for example when cleaning raccoon latrines. Because humans are a false host for the roundworm, diseases are very rare.

attitude

The raccoon is occasionally kept as a pet, especially in the USA, but many experts advise against this as it is not a domesticated species and can behave unpredictably and aggressively.[99][100] In many American states it is therefore forbidden to keep raccoons unless, as in Germany, at least a permit to keep exotic pets is required.[101][102] In the state of Berlin, feeding and keeping raccoons is generally prohibited under state law.[103] In the United States, privately held raccoons that have bitten a human are regularly killed for rabies screening.

Many sexually mature raccoons behave aggressively during the mating season and bite suddenly.[99] Spaying and neutering at the age of five or six months significantly reduces the likelihood of such behaviors occurring.[104] If they don't get enough exercise or are improperly fed, raccoons can become obese or develop behavioral disorders. With regard to the latest research results on the social behavior of raccoons, some owners are now of the opinion that they should not be kept alone if possible so that they do not become lonely.[105]

Fur processing