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Raccoons in Europe (Germany)
Abstract
The raccoon is a half-bear native to North America. It’s an omnivore that can reach a weight of some nine kg and a body length of 70 cm. Its black face mask and long tail are characteristics that make the animal unique in appearance and easy to identify. Another distinctive feature is the raccoon’s very dexterous front paws.
Since introduction in 1934, the raccoon population in Germany has grown by 12–17% annually, now numbering around a million. It's an opportunistic consumer that eats what's plentiful, from small rodents, birds, and fish to amphibians, mollusks, and insects. The question of ecological effects is intensively debated, but there is, so far, little or no scientific data that shows any significant negative effects of raccoon predation on any native species. Food competition doesn't seem to be a big problem for any native predator either, as the raccoon shifts to something else when one of its food sources gets sparse. In cities and suburbs, the raccoon can cause significant economic damage. The population forecast is for a continued increase in numbers and geographic spread. Urban populations constitute a growing problem with fecal and urine contamination of the places the animals select for their “communal toilets.”
... The raccoon, Procyon lotor, is a medium-sized carnivore whose native distribution in North America extends from southern Canada to Panama (Zevelhof, 2002). Raccoons were successfully introduced in Germany, in the 1930s with a limited number of individuals (Jernelöv, 2017). Recent genetic analyses suggest that there were at least four small-scale, independent initial introduction events of raccoon (Fischer et al., 2017). ...
... The lack of a diversity gradient, along with the lack of private alleles, suggests mixing of individuals from different introduced areas in the new colonized range. On the other hand, the allele frequencies in D1, the location of the first recorded raccoon introduction (Jernelöv, 2017), was the only site characterized by evenly distributed allele frequencies. Such a pattern can be explained by some form of balancing selection (Mukherjee, Sarkar-Roy, Wagener, & Majumder, 2009;Takahata, 1990) that plays an important role in shaping MHC diversity at an invasion core (White & Perkins, 2012), while the diversity of newly established populations at the invasion edges may be shaped more by genetic drift. ...
... In a study of fluctuating population sizes of water voles (Bryja, Charbonnel, Berthier, Galan, & Cosson, 2007), balancing selection acted on the MHC locus during the high-abundance year. In our study, we also found lower differentiation displayed by the immune-related locus, at high migration rates during intensive population spread (Jernelöv, 2017). This pattern suggests uniform selection pressures exerted by pathogens in Polish and German raccoon populations. ...
The adaptive potential of invasive species is related to the genetic diversity of the invader, which is influenced by genetic drift and natural selection. Typically, the genetic diversity of invaders is studied with neutral genetic markers, however, the expectation of reduced diversity has not been consistently supported by empirical studies. Here, we describe and interpret genetic diversity at both neutral microsatellite loci and the immune related MHC‐DRB locus of native and invasive populations of raccoon to better understand of how drift and selection impact patterns of genetic diversity during the invasion process. We found that despite the loss of many MHC alleles in comparison with native populations, functional MHC supertypes are preserved in the invasive region. In the native raccoon population the number of supertypes within individuals was higher than expected under a neutral model. The high level of individual functional divergence may facilitate the adaptation to local conditions in the invasive range. In the invasive populations, we also detected increased population structure at microsatellites compared to the MHC locus, further suggesting that balancing selection is acting on adaptively important regions of the raccoon genome. Finally, we found that alleles known to exhibit resistance to rabies in the native range, Prlo‐DRB*4, Prlo‐DRB*16 and Prlo‐DRB*102, were the most common alleles in the European populations, suggesting directional selection is acting on this locus. Our research shows empirical support for the importance of functional immune diversity for adaptation and survival in novel environments.
... The raccoon is a medium-sized carnivore whose native distribution in North America extends from southern Canada to Panama 30 . The first successful introduction in Europe occurred in Germany in the 1930s with a limited number of individuals 31 . Recently, approximately 1,000,000 raccoons were estimated to be living in Germany, and the range of the species in Europe has extended to the west, east and south of the invasion core 32,33 . ...
Understanding the evolutionary mechanisms behind invasion success enables predicting which alien species and populations are the most predisposed to become invasive. Parasites may mediate the success of biological invasions through their effect on host fitness. The evolution of increased competitive ability (EICA) hypothesis assumes that escape from parasites during the invasion process allows introduced species to decrease investment in immunity and allocate resources to dispersal and reproduction. Consequently, the selective pressure of parasites on host species in the invasive range should be relaxed. We used the case of the raccoon Procyon lotor invasion in Europe to investigate the effect of gastrointestinal pathogen pressure on non-MHC immune genetic diversity of newly established invasive populations. Despite distinct differences in parasite prevalence between analysed populations, we detected only marginal associations between two analysed SNPs and infection intensity. We argue that the differences in parasite prevalence are better explained by detected earlier associations with specific MHC-DRB alleles. While the escape from native parasites seems to allow decreased investment in overall immunity, which relaxes selective pressure imposed on immune genes, a wide range of MHC variants maintained in the invasive range may protect from newly encountered parasites.
... In contrast to North America, the overall perception of urban raccoons in Europe does not appear to be solely negative. The animals are often even fed by residents in gardens or housing developments [32,63,65]. Over the decades, all attempts to control raccoon populations in urban areas have proven ineffective. ...
Simple Summary
With the advance of modern civilization, there has been intensive contact among large parts of the world. This has not only encouraged increased travel and trade, but has also led to the anthropogenic introduction of animal and plant species into new areas of settlement. Such neozoa (invasive species) encounter different and sometimes completely new environmental conditions, which requires the adaptation of the neozoa to their new habitat. Under certain circumstances, the neozoa may even have significant survival advantages, for example, if the prey–hunter constellation shifts in their favor. The North American raccoon (Procyon lotor) was introduced into Europe by intentional and accidental releases in the 20th century and spread throughout most of Europe in the following decades. The first release was in Germany, in Central Europe, which is still the distribution hotspot of the European raccoon. Over time, raccoons were released into the wild for hunting and subsequently spread. There have also been repeated unintentional releases of raccoons by breeders, fur farms, and private pet owners. These releases have accelerated the spread of the raccoon in Europe. The influence of the raccoon on the native fauna and flora has been insufficiently studied so far, but it seems to be only marginal according to current knowledge.
Abstract
The raccoon (Procyon lotor) is a North American half-bear that is present in much of Europe and Asia as a result of both accidental and planned releases. In Europe, raccoons were introduced primarily as a source of fur for the fur industry. In the 1930s, raccoons were released into the wild in Central Europe. At the same time, animals from fur farms and private holdings continued to enter the wild. In the following decades, the raccoon spread over large parts of Europe. In addition to the invasive spread of the Central European initial population, individual releases of raccoons occurred frequently, mainly in Southern Europe. The high adaptability of the raccoon favors its expansion into new habitats. It has a high reproductive rate, is very mobile, and encounters few predators in Europe. Raccoons have recently become a topic of interest when large raccoon populations have colonized suburban and urban areas. Despite the proximity of raccoons and humans, however, there have been hardly any conflicts to date, unlike in North America. A significant negative impact on the native fauna has been suspected but not proven. Raccoons have been identified as vectors of zoonotic diseases. Nevertheless, monitoring of the increasing numbers of raccoons in Europe seems advisable.
... The raccoon is a medium-sized carnivore whose native distribution in North America extends from southern Canada to Panama (Zevelhof, 2018). Its first successful introduction in Europe occurred in Germany in the 1930s with a limited number of individuals (Jernelöv, 2017). Genetic analyses of a large set of microsatellite loci and mitochondrial DNA based on a whole-country sampling suggest that the current German population of raccoon was established by at least four small-scale, initial independent introduction events (Fischer et al., 2017). ...
Rapid adaptation is common in invasive populations and is crucial to their long‐term success. The primary target of selection in the invasive species' new range is standing genetic variation. Therefore, genetic drift and natural selection acting on existing variation are key evolutionary processes through which invaders will evolve over a short timescale. In this study, we used the case of the raccoon Procyon lotor invasion in Europe to identify the forces shaping the diversity of immune genes during invasion. The genes involved in the defence against infection should be under intense selection pressure in the invasive range where novel pathogens are expected to occur. To disentangle the selective and demographic processes shaping the adaptive immune diversity of its invasive and expanding populations, we have developed species‐specific single‐nucleotide polymorphism markers located in the coding regions of targeted immune‐related genes. We characterised the genetic diversity of 110 functionally important immune genes in two invasive and one native raccoon genetic clusters, each presenting a different demographic history. Despite the strong effect of demographic processes in the invasive clusters, we detected a subset of genes exhibiting the diversity pattern suggestive of selection. The most likely process shaping the variation in those genes was balancing selection. The selected genes belong to toll‐like receptors and cytokine‐related genes. Our results suggest that the prevalence of selection depends on the level of diversity, that is – less genetically diverse invasive population from the Czech Republic displayed fewer signs of selection. Our results highlight the role of standing genetic variation in adapting to new environment. Understanding the evolutionary mechanisms behind invasion success would enable predicting how populations may respond to environmental change.
... In both regions, the raccoon inhabits wetlands and riparian habitat as well as urban areas that provide abundant food [37]. The raccoon is an opportunistic and omnivorous species and uses almost any available food resource in both types of habitats: rodents, birds, and their eggs, fish, and amphibians [37][38][39]. ...
Background:
Parasites may mediate the success of biological invasions through their effect on host fitness and thus, on host population growth and stability. However, a release from the pressure of parasites is strongly related to the genetic differentiation of the host. In invasive host populations, the number of available genetic variants, allowing them to 'fight' the infection, are likely to be influenced by founder events and genetic drift. The level standing genetic variation of invasive populations may be crucial in successfully adapting to new environments and resisting diseases. We studied invasive populations of raccoon that experienced a random reduction in genetic diversity during the establishment and evaluated the relationship between host immune genetic diversity and intestinal parasites infection.
Results:
We distinguished two different genetic clusters that are characterized by different sets of functionally relevant MHC-DRB alleles. Both clusters were characterized by considerably different allele-parasite associations and different levels of parasite infection. The specific resistance MHC-DRB alleles explained the lower prevalence of Digenea parasites. An increased infection intensity was related to the presence of two MHC-DRB alleles. One of these alleles significantly decreased in frequency over time, causing a decrease of Digenea abundance in raccoons in consecutive years.
Conclusions:
Our findings suggest that intestinal parasites can exert selective pressure on an invasive host with lowered levels of immune genetic diversity and contribute to promoting local adaptation over time. The random genetic drift that created the two different genetic clusters in the invasive raccoon range imposed completely different MHC-parasite associations, strongly associated with the infection status of populations. Our findings underline the role of standing genetic variation in shaping host-parasite relationships and provide empirical support that functional genetic variation may be, at least partly, responsible for differences in the success of invasive populations.
Background
The introduction of non-native species can cause significant ecological and economic impacts by disrupting local habitats and ecosystem services. Due to its central European location and extensive trade networks, Germany is particularly susceptible to the introduction and spread of non-native species. Here, we compiled the first comprehensive list of established non-native species in Germany, detailing the invaded environments, native regions, and documented impacts.
Results
The final list included 1962 established non-native species from 594 families and 35 phyla, with Tracheophyta (n = 839), Arthropoda (n = 612), and Chordata (n = 129) being the most represented. Most of these species were terrestrial (79.3%), followed by semi-aquatic (8.4%), with less than 5% occupying freshwaters and other ecosystems. This study highlights a significant lack of information on the impacts of non-native species in Germany, with 97.9% of species having unknown effects. The greatest number of species included in this list were native to the Palearctic region (n = 813), followed by the Nearctic (n = 365) and Neotropic (n = 127) regions. However, many species were of unknown origin (n = 335), with a smaller subset classified as widespread (n = 166).
Conclusions
This first comprehensive list of established non-native species is essential for guiding management strategies in Germany. By cataloguing established non-native species and their impacts, it provides policymakers and stakeholders with a clearer understanding of which species are present, their patterns of spread, and their potential impacts, enabling them to prioritise management efforts for the most harmful species.
The expansion of invasive alien species is a major threat to the environment and economy. Animal invasions, especially by raccoons Procyon lotor are increasingly harmful. Raccoons' reduced neophobia enables easy adaptation to humans and surroundings. They exploit human presence in their natural habitat. Camera traps and direct observations in Germany's Lower Oder Valley National Park and Poland's Lower Oder Valley Landscape Park revealed raccoons' cognitive abilities and effective learning processes. This study demonstrates their rapid learning in finding and opening traps, removing bait, killing and eating trapped rodents. To minimize disturbance by raccoons, we recommend to preselect study plots without raccoons or to use of protective devices.
Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as “small dogs,” especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.
A 17‐month‐old boy from Vancouver, Canada, presented with a 5‐day history of progressive somnolence, ataxia, and torticollis. Additional investigations revealed eosinophilic encephalitis with deep white matter changes on MR imaging. On day 13, serology came back positive for Baylisascaris procyonis antibodies. While prophylaxis after ingestion of soil or materials potentially contaminated with raccoon feces can prevent baylisascariasis, timely treatment can sometimes alter a disastrous outcome. Populations of infected raccoons are propagating globally, but cases of Baylisascaris neural larva migrans have so far only been reported from North America.
In this study we present the results of a baseline study designed to assess the status of the raccoon (Procyon lotor) throughout Spain. The species was reported in 28 localities, mostly consisting of sporadic observations of single individuals. In central Spain an apparently thriving population of raccoons has been recently discovered. Our data confirmed the spread of feral raccoons throughout this region, where the species has already colonized about 100 km of streams and rivers. Predation on local fauna was also proved, and the first approximation for spatial movement and habitat use analyses in Spain is presented. Our results suggest that deliberate releases of raccoons by pet owners are an important cause for the existence of feral raccoons in Spain. Further research should focus on monitoring established individuals to collect detailed data on their population and reproductive parameters. Meanwhile, urgent actions should be taken to stop releases into the wild and to control and eradicate this unwelcome invasive species.
From the past, species have been transferred among ecosystems trough traveling and global trade. The establishment and spread of such invasive species has caused significant damage to the economy, the environment, and human or native species health. This review compiles information on infections or contact with pathogens reported in raccoons (Procyon lotor). Raccoons are opportunistic carnivores native to North America. However, nowadays they are distributed across mainland Europe as a result of escaped pets and introductions. In their native range, raccoons are known to be host to a number of disease agents that could be transmitted to humans, domestic animals and other wildlife. Hence, the increase of raccoon populations and their geographic spread in Europe may result in new disease hazards. Raccoons have been identified as possible sentinels of diseases such as West Nile virus, and they pose a disease-related conservation risk by maintaining circulation of canine distemper virus. They also have the potential to participate in the maintenance of zoonoses including the raccoon roundworm Baylisascaris procyonis. Due its fast expansion and the large list of diseases, we conclude that the introduction of the raccoon has had adverse effects on health in Europe. This might well be the case of other invasive species, too. Hence, studies on invasive species health aspects are urgently needed to assess the risk of disease spread and eventually establish control measures.
Preliminary results on the ecology of raccoon in Poland are presented. The use of space (by radiotelemetry), diet composition and parasite infections (both by scat analy-sis) were investigated. The home-range size of the raccoon in western Poland averaged 1 km 2 in suburban areas (n = 5 individuals), 10 km 2 in the Warta Mouth National Park wetland area (n = 5), and 60 km 2 for a single individual studied inhabiting woodlands. Space use patterns in relation to habitat type were also studied. About 44% of the biomass consumed by raccoons were mammals, 41% other vertebrates, 12% inverte-brates, 2% plant material and only 1% eggs. Three species and one genus of helminths, e.g. the humans pathogen parasite, Baylisascaris procyonis, were identified.
Terrestrial wildlife rabies has been successfully eliminated from Germany predominantly as a result of the distribution of oral rabies vaccine baits. In case that wildlife rabies would re-emerge among its known reservoir species in Germany, swift action based on previous experiences could spatially and temporally limit and subsequently control such an outbreak. However, if rabies emerged in the raccoon population in Germany (Procyon lotor), there are no tools or local experience available to cope with this situation. This is especially worrisome for urban areas like Kassel (Hesse) due to the extremely high raccoon population density. A rabies outbreak among this potential reservoir host species in these urban settings could have a significant impact on public and animal health.
The raccoon Procyon lotor has been naturalised in Germany since 1927. The most dense populations exist in the states Hessia, Northrhine‐Westphalia and Lower Saxony followed by Bavaria, Thuringia, Brandenburg and Mecklenburg‐Vorpommern. By 1985, the raccoon had crossed the borders to Germany's neighbouring countries with the exception of the Danish and Polish borders. The factors limiting population growth are the numbers of suitable resting and breeding places ‐ for which raccoons prefer oaks and beeches ‐ and food supply. The raccoon has not been shown to negatively affect any indigenous wildlife species. In Hessia, plant matter, invertebrates and vertebrates each make up about one third of the diet of the raccoon. Mammals, birds, reptiles, amphibians and fish are important in winter and spring. Invertebrates can be found in considerable amounts all year long, with the maximum percentages found in summer. Plants are the main source of food in autumn. The raccoon has not yet become a problematic species, not even in urban areas. However, cases of rabies in raccoons in Germany have been documented, although seldom compared to fox Vulpes vulpes , marten Martes spp. and deer, e.g Cervus elaphus, Capreolus capreolus and Dama dama. Raccoons are also known as carriers of infectious diseases such as canine distemper, panleucopenia, Aujeszky's disease, canine parvovirus and canine adenovirus. The first case of human infection by a parasite, the ascarid Baylisascaris procyonis , from a pet raccoon was reported in 1991. The extermination of the raccoon population is not considered to be feasible. The yearly hunting bag of raccoons in Germany comprises 2,000–3,000 individuals.
Von 1976 bis 1979 wurden 150 Magen-Darm-Trakte und 250 Losungen des Waschbren (Procyon lotor [L.]) aus Nordhessen und angrenzenden Teilen von Nordrhein-Westfalen auf ihren Nahrungsinhalt untersucht. Annhernd jeweils ein Drittel der Nahrungsanteile entfallen auf Wirbeltiere, Wirbellose und Pflanzen. Jahreszeitlich bedingte Schwankungen der Beuteanteile sind naclizuweisen.From 1976 to 1979, 150 stomach/intestinal tracts and 250 faeces of raccoon (Procyon lotor [L.]) from North-Hessen and adjoining areas of North-Rhine Westphalia were examined on the basis of their food content. In each case, approximately one third of the food components were vertebrates, invertebrates and plants. Seasonal differences in the prey material can be detected.De 1976 1979, le contenu alimentaire de 150 tractus digestifs et de 250 chantillons de matire fcale de ratons laveurs (Procyon lotor [L.]) rcolts dans le Nord de la Hesse et dans les rgions limitrophes de Rhnanie-Westphalie a t analys. Les Vrtbrs, les Invertbrs et les vgtaux se partagent chaque fois approximativement le tiers du contenu stomacal. Des variations saisonnires des quantits de proies sont dcelables.
Paramyxoviruses are responsible for considerable disease burden in human and wildlife populations: measles and mumps continue to affect the health of children worldwide, while canine distemper virus causes serious morbidity and mortality in a wide range of mammalian species. Although these viruses have been studied extensively at both the epidemiological and the phylogenetic scales, little has been done to integrate these two types of data. Using a Bayesian coalescent approach, we infer the evolutionary and epidemiological dynamics of measles, mumps and canine distemper viruses. Our analysis yielded data on viral substitution rates, the time to common ancestry, and elements of their demographic history. Estimates of rates of evolutionary change were similar to those observed in other RNA viruses, ranging from 6.585 to 11.350 x 10(-4 )nucleotide substitutions per site, per year. Strikingly, the mean Time to the Most Recent Common Ancestor (TMRCA) was both similar and very recent among the viruses studied, ranging from only 58 to 91 years (1908 to 1943). Worldwide, the paramyxoviruses studied here have maintained a relatively constant level of genetic diversity. However, detailed heterchronous samples illustrate more complex dynamics in some epidemic populations, and the relatively low levels of genetic diversity (population size) in all three viruses is likely to reflect the population bottlenecks that follow recurrent outbreaks.
Genetic evidence for multiple introduction events of raccoons
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- M J Ruiz-López
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- L S Eggert
- J T García
Achtung, Panzerknacker. Waschbär - Bedrohung für heimische Arten
- R Schneider
Raccoons: A natural history
- S I Zeveloff
- SI Zeveloff
Neozoen-eine neue Gefahr für die Reliktpopulationen der Europäischen Sumpfschildkröte in Nordostdeutschland
- N Schneeweiss
- M Wolf
Der Waschbär (3. aktual. Aufl., 200 S)
- U Hohmann
- I Bartussek
Der Waschbär (Procyon lotor Linné, 1758) in Deutschland-eine Konfliktart? Bachelorarbeit Georg-August
- S Becker
Interspecific competition of the raccoon (Procyon lotor) and the wildcat (Felis silvestris silvestris) with regard to rest sites in Germany
- U Hohmann
- K Hupe
Stand und Perspektiven der Erforschung des Waschbären in Deutschland
- U Hohmann
Erfahrungen mit ausgewählten Säugetierarten und ihr zukünftiger Status
- W Lutz
Waschbären erobern Deutschland
- V Dröscher
Untersuchungen zur Raumnutzung des Waschbären (Procyon lotor, L. 1758) im urbanen Lebensraum am Beispiel der Stadt Kassel (Nordhessen). 25
- Frank-Uwe Michler
Untersuchungen zur Nahrungsbiologie des Waschbären (Linné 1758) und zum Einfluß auf andere Wildarten in seinem Lebensraum
- W Lutz
Untersuchungen zum Waschbären (Procyon lotor Linné, 1758) im Raum
- D Helbig
Jäger Hubertus Ostermann kämpft gegen die Ausbreitung der Allesfresser Volkstimme
- Waschbären Haben Keine Feinde
Raccoons: In folklore, history & today’s backyards (p. 157)
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Waschbären im Stadtgebiet.-Wildbiologie International 5
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Beobachtungen zur Koexistenz von Mittelspecht und Waschbär
- D Horstmann
- B Schmincke
Baylisascariose (Baylisascaris procyonis)-eine seltene parasitäre Zoonose in Europa
- C Bauer
Waschbären - Einwanderer aus Wild West. Mittwoch, 30.10
- Tierreich Expeditionen Ins
Mai) Ökologische und ökonomische Bedeutung des Waschbären in Mitteleuropa - Eine Stellungsnahme
- F.-U Michler
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Raccoons: In folklore, history & today’s backyards
- V C Holmgren
- VC Holmgren
Tierische Invasoren breiten sich schnell aus
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Der Waschbär (Procyon lotor Linné, 1758) in Deutschland - eine Konfliktart?
- S Becker
Der Waschbär (in German)
- U Hohmann
- I Bartussek
- B Böer