Hormonbehandlade mårdhundstikar : en framtida förvaltningsmetod för att förhindra en storskalig etablering av mårdhund i Sverige?

Abstract: Invasive alien species represents a seriously threat against the global biological diversity. The raccoon dog (Nyctereutes procyonoides) is an omnivorous carnivore native to the eastern parts of Asia. About 9000 raccoon dogs were introduced in the European parts of former Soviet Union during the years 1929-1955 for its value as a fur producing game species, and have since then taken a wide dispersal over large areas of Europe. Except the biological diversity, the raccoon dog is also a threat against humans and animal’s health by its ability to carry harmful diseases. Since the beginning of the 21th century, the raccoon dog has expanded to the northern parts of Finland and can today be found in Swedish areas bordering Finland, primarily in Tornedalen. The year 2008, the Raccoon dog project started in Sweden with the aim to prevent a large-scale dispersal of the species within the country. Also Finland, Denmark and Norway have later been involved and the project is now an international co-operative project. The project is managed by the Swedish Association for Hunting and Wildlife Management and has been successful so far. An effective management method has been to sterilize and provide animals with a transmitter collar (Judas animals), whereby these Judas animals find and disclose new unknown raccoon dogs, which have been tagged or culled. During year 2014, a pilot project with hormone treated raccoon dog females started. The hormone that is used effects the reproductive organs so that the females appear to be in estrus also outside the normal reproductive season. In theory a female with induced estrus outside the reproductive season would be very attractive for unknown males. The main question with this exam work was to investigate if hormone treated Judas females was more efficient to attract males than untreated females. During the project, I also investigated if the animals movement pattern, condition and physique was effected by the treatment. The project has ethical permission (A38-13) and exceptions from regulations in the hunting legislation for capturing of raccoon dog (NV-01782-14). Autopsies of the animals connected to the study were done by the National Veterinary Institute (SVA). The study had too few Judas animals to make any statistically significant conclusions about the hormone treated animals effectivity, but only hormone treated females found partners during the experiment. The home range size was similar for the treated- and non-treated animals, but the hormone animals showed a tendency to a more intense movement pattern. The Judas animals didn’t show any seriously negative effects during the time of the treatment, but awareness of possible side effects should be considered in further studies. A larger sample size is necessary to possibly confirm a statistical higher effectivity among the hormone treated animals.