Raccoon, raccoon dog & Co: Risks of invasive and non-native predator species for health and ecology

The raccoon, raccoon dog, mink and golden jackal are not native to Germany or Europe, but are increasingly spreading in these non-native regions. The joint research project ZOWIAC "Zoological and ecological effects of invasive carnivores on the animal world" of the Goethe University and the Senckenberg Gesellschaft für Naturforschung is investigating how these invasive and non-native species threaten biological diversity and which diseases they can transmit to humans and animals. Due to their wide range of food and high adaptability, these animals can live in almost any natural habitat. 

They are suspected of being partly responsible for the decline of numerous native species, some of which are endangered, such as bats, various species of amphibians and reptiles, and ground-nesting birds. The project will also investigate whether relocating them to urban areas promotes the transmission of pathogens to humans and animals, so-called zoonoses. A zoonosis brought to Europe by raccoons is the raccoon roundworm (Baylisascaris procyonis), whose eggs are spread through the animals' faeces. This poses a potential threat to human health, especially in cities where raccoons use anthropogenic food resources and spaces. Raccoons also serve as reservoir hosts for coronaviruses, lyssaviruses (rabies), canine distemper virus, and West Nile virus.

Goal

The project aims to study invasive carnivorous species such as the raccoon (Procyon lotor), the raccoon dog (Nyctereutes procyonoides) and the mink (Neovison vison) for their impact on native fauna and human communities. Various methods are used for this study, including standard methods for studying parasitic loads, predatory behavior, potential disease transmission, and citizen science or spread modelling.

Methodologies

The ZOWIAC project encompasses wildlife biology and genetics in equal measure. There is a systematic monitoring of the most frequently associated pathogens. In addition, spatial aspects in particular are taken into account, established populations in urban and rural regions (agriculture/forestry/water bodies). Daily movement patterns can be determined by individuals with radio collars. The metabarcoding of the stomach and faecal samples provides detailed information about the food spectrum and the parasite fauna in order to be able to better assess possible effects on biodiversity and zoonotic potential.

The method I have used so far has been researching online literature in scholarly journals through academic platforms. Another method during my research work was the daily laboratory work. Fillimi with the specimens of the raccoon (Procyon lotor) Study of the species Filloi with the advice of my supervisor and using the preparation protocol. First the linear measurements of the species were made, then I examined the ectoparasites in the dorsal surface of the animal, further with the cranial and caudal parts of the body. Second, for further investigation, we searched for the organs of the species and looked for endoparasites. From the tongue to the intestines, all examinations were carried out microscopically. Other species such as the raccoon dog (Nyctereutes procyonoides) have also been studied using the same method. In addition, There are also tissue samples and stool samples for DNA analysis. Currently, the species for laboratory studies is the Egyptian goose (Alopochen aegyptiaca). In addition, there are samples of the raccoon and raccoon dog for the next future study with biological laboratory methods and analysis.

Results

Referring to laboratory results, alien invasive species have been found to transmit ectoparasites and endoparasites. During visual inspection, ectoparasites living on the outer surface of hosts were found, such as; Louse (Pediculus humanus capitis). Further investigations were carried out on the internal body parts and organs of the species. The endoparasites were found in the gut of the species; The roundworms (Nematoda). In addition, upon careful examination of the inner portion of the cecum, the digenea a class of trematodes in the phylum Platyhelminthes, consisting of parasitic flatworms with a syncytial tegument, what found.Further research revealed that the invasive species were hosts of the parasitic worm Acanthocephala, thornworms or thornworms,