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Raccoons (Procyon lotor) in Sweden - A risk assessment for the establishment of the raccoon as an invasive alien species

Björk, Julia (2018) BIOM02 20181
Degree Projects in Biology
Abstract
Invasive alien species are organisms that have been introduced to an area outside their natural distribution range and threatens animals, habitats or humans in the new area. The raccoon (Procyon lotor) is a mesopredator originating from North and Central America that has been introduced in Europe and Asia. Since the first European introductions of raccoons in Germany, natural dispersal and pet trade have resulted in a wide European distribution and the species is currently invasive in several countries. This study aims to investigate the risk of a raccoon establishment and its potential impacts on native species, plant populations, domestic animals, human health, ecosystem services and infrastructure in Sweden. The risk assessment was... (More)
Invasive alien species are organisms that have been introduced to an area outside their natural distribution range and threatens animals, habitats or humans in the new area. The raccoon (Procyon lotor) is a mesopredator originating from North and Central America that has been introduced in Europe and Asia. Since the first European introductions of raccoons in Germany, natural dispersal and pet trade have resulted in a wide European distribution and the species is currently invasive in several countries. This study aims to investigate the risk of a raccoon establishment and its potential impacts on native species, plant populations, domestic animals, human health, ecosystem services and infrastructure in Sweden. The risk assessment was performed with the Internet based Harmonica+ and Pandora+ protocols. The invasion risk is 0.50 (medium) and the impact risk is 0.50 (medium), resulting in a total risk score of 0.250 (low). Hence, the risk that the raccoon will become an alien species in Sweden is medium whereas the risk for it becoming an invasive alien species is low. However, studies about potential predation and competition with native species in invaded areas are scarce, resulting in a low certainty for several impacts. Therefore, the ecological damage could be greater than predicted in this report. (Less)
Popular Abstract
Raccoons: cute guests or threats?

What do garden lupin (Lupinus polyphyllus), American mink (Neovision vision) and signal crayfish (Pacifastacus leniusculus) have in common? All of them are invasive alien species (IAS) in Sweden and have a negative impact on native species by competition or predation. Another species may apply for a membership in the Swedish IAS-club: raccoon (Procyon lotor)

IAS are species that have been introduced, often by human actions, to an area outside their natural distribution range, where they threaten biological diversity, human health, plant health, animal health and/or socio-economic values. The invasion process model describes the invasion stages a species must overcome in order to be called an... (More)
Raccoons: cute guests or threats?

What do garden lupin (Lupinus polyphyllus), American mink (Neovision vision) and signal crayfish (Pacifastacus leniusculus) have in common? All of them are invasive alien species (IAS) in Sweden and have a negative impact on native species by competition or predation. Another species may apply for a membership in the Swedish IAS-club: raccoon (Procyon lotor)

IAS are species that have been introduced, often by human actions, to an area outside their natural distribution range, where they threaten biological diversity, human health, plant health, animal health and/or socio-economic values. The invasion process model describes the invasion stages a species must overcome in order to be called an invasive species: introduction, establishment, spread and impact. Identifying species that may become invasive is important in order to prevent an establishment. Risk assessments are tools for identifying species that may become invasive by evaluating the potential risk for introduction, establishment, spread and impact in a specific area.

Raccoons are middle-sized omnivores that are native to North-and Central America. Raccoons are loved for their cute appearance but also for their habit of “washing” food. Indeed, raccoons are amazing animals: their paws are highly adapted for manipulating many different objects and they are both skilled climbers and swimmers. Raccoons are diet- and habitat generalists, which makes them able to survive and flourish in several environments. Today, raccoons are invasive in several European countries due to introductions by humans.
How big is the risk for a raccoon establishment in Sweden?
Raccoons have been observed in Sweden 5 times since 2005, and these individuals are probably former pets or individuals that have hitchhiked on vehicles into Sweden from other countries. In North America raccoons are known to reduce nesting success in many bird species by predation on eggs and nestlings and to damage crops, especially maize and soybeans. Studies from Europe are scarce or lacking, but similar effects may exist in Europe. Raccoons can also spread several diseases (e.g. rabies, canine distemper) and are hosts for many parasites, including the raccoon roundworm, which can kill intermediate hosts. Raccoons often live in urban areas and could damage buildings and gardens in their search for den sites and food.

According to my results the risk of a reproducing raccoon population in Sweden that pose a negative impact on native species, human health, animal health, ecosystem services and economy is low. However, information about raccoons in Europe and their impact on the environment is scarce, and more research is needed in order to better understand raccoons and their interactions with newly invaded areas. The establishment of raccoons in Sweden could possibly be a great threat to species of conservation concern, especially in wetland habitats.

Master’s Degree Project in Biology 30 credits 2018
Department of Biology, Lund University

Advisor: Ola Olsson and Nils Carlsson
Lund University and Länsstyrelsen (Less)
Please use this url to cite or link to this publication:
author
Björk, Julia
supervisor
organization
course
BIOM02 20181
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8958672
date added to LUP
2018-09-13 15:44:04
date last changed
2018-09-13 15:44:04
@misc{8958672,
  abstract     = {Invasive alien species are organisms that have been introduced to an area outside their natural distribution range and threatens animals, habitats or humans in the new area. The raccoon (Procyon lotor) is a mesopredator originating from North and Central America that has been introduced in Europe and Asia. Since the first European introductions of raccoons in Germany, natural dispersal and pet trade have resulted in a wide European distribution and the species is currently invasive in several countries. This study aims to investigate the risk of a raccoon establishment and its potential impacts on native species, plant populations, domestic animals, human health, ecosystem services and infrastructure in Sweden. The risk assessment was performed with the Internet based Harmonica+ and Pandora+ protocols. The invasion risk is 0.50 (medium) and the impact risk is 0.50 (medium), resulting in a total risk score of 0.250 (low). Hence, the risk that the raccoon will become an alien species in Sweden is medium whereas the risk for it becoming an invasive alien species is low. However, studies about potential predation and competition with native species in invaded areas are scarce, resulting in a low certainty for several impacts. Therefore, the ecological damage could be greater than predicted in this report.},
  author       = {Björk, Julia},
  language     = {eng},
  note         = {Student Paper},
  title        = {Raccoons (Procyon lotor) in Sweden - A risk assessment for the establishment of the raccoon as an invasive alien species},
  year         = {2018},
}