Analysis of the Interaction Between the Golden Jackal, the Grey Wolf
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Habitat Suitability Model for the Golden Jackal (Canis aureus) in Friuli Venezia Giulia and Analysis of Possible Interaction with the Grey Wolf (Canis lupus) and the Red Fox (Vulpes vulpes) A GIS Based Modelling Approach Ursula Maria STERRER, BSc BSc 01017343 Innsbruck, December 2019 Master Thesis Submitted at the Leopold Franzens University Innsbruck, Faculty of Biology for achieving the academic degree Master of Science Supervised by: Dr. Johannes Rüdisser Institute of Ecology at the Leopold Franzens University Innsbruck & Stefano Filacorda, PhD Faculty of Science and Technology at the Free University of Bozen/Bolzano ACKNOWLEDGEMENTS First, I would like to thank my supervisors, Dr. Johannes Rüdisser and Stefano Filacorda, PhD for helping me with this master thesis. Special thanks to Johannes Rüdisser, who helped me with questions concerning my work in GIS. It was also a truly great experience to be able to collect at least part of the data myself in Friuli Venezia Giulia with Stefano Filacorda. Also thank you to all the people involved in the research being conducted in Udine and for letting me use all the data you collected over the last decade, without which this thesis would not be what it is now. I want to thank my family, that has supported me throughout my whole university career and who never fail to give me great advice. I would also like to thank Florin Kunz, who was always there for me and gave me the support I needed in times, when finishing the master thesis seemed far away. Thank you for listening to my struggles and for our great discussions. Thanks to all my fellow EMMA’s who made the last years so great, and especially to Kat, for reading and reviewing this thesis. II ABSTRACT Modelling species distribution and understanding the effects that a guild of predators has on each other is of great interest not only from an ecological point of view but also for management decisions. Golden jackals (Canis aureus) have been expanding their range from eastern Europe to the west and successfully established populations in Friuli Venezia Giulia. The grey wolf (Canis lupus) has made its return to the region recently with the first evidence of reproduction in 2018 in the area of Magredi. The red fox (Vulpes vulpes) is highly abundant in Friuli Venezia Giulia and the effects the larger predators could have on this animal are still unknown. This study aims to model suitable habitat for the golden jackal to gain more information of this species’ habitat use and altitudinal preferences. Furthermore, I want to investigate possible effects that the three canids could have on each other by interpreting the presence records and camera trap pictures. I modeled the habitat suitability with Maxent. Therefore, we collected presence data on all large and medium-sized mammals occurring in the region with three different methods. In 2019, we added data to an existing dataset (from 2010-2018) of acoustic stimulation surveys of golden jackals. Additionally, we collected presence data through snow & mud tracking and through opportunistically placed camera traps. The habitat suitability model showed, that golden jackals prefer habitats along rivers, forests in the colline and montane altitudinal belt and extensively used agricultural fields. The sandy gravel banks along rivers seem to be especially important. The habitat suitability model indicates, that large parts of the region, especially in the plains in the middle part of the region and the northern mountain valleys, are suitable for the golden jackal. Golden jackals were found in significantly lower altitudes than grey wolves and red foxes respectively. In the region, where reproductive grey wolves are present in the lowlands, the golden jackals stopped answering to acoustic stimulation which could be a sign of intraguild competition (Lapini et al. 2018). From the camera traps, I was able to analyze the habitat use of golden jackals and red foxes in one specific case. Although it is not enough data for statistical analysis, it seems as if red foxes choose to be present in the habitat on different days than the golden jackals, therefore engaging in a behavior of avoidance. Further research is required to get more in depth information on the behavior of the three species. III Nicht nur aus einem ökologischen Blickwinkel, sondern auch für Entscheidungen im Management von Arten, ist es wichtig, Kenntnis über die Artverteilung und Interaktion von Beutegreifern zu erlangen. Der Goldschakal (Canis aureus) hat sein Territorium ausgehend von Ost-Europa erfolgreich in den Westen ausgedehnt und Populationen haben sich auch in Friaul- Julisch-Venetien angesiedelt. Der Wolf (Canis lupus) ist in der jüngsten Zeit ebenfalls in die Region zurückgekehrt und 2018 gab es in Magredi den ersten Reproduktionsnachweis. Der Fuchs (Vulpes vulpes) ist in der Region zahlreich vorhanden, allerdings sind die Effekte, die die größeren Raubtiere auf die Art haben noch weitgehend unbekannt. Diese Arbeit versucht ein Modell geeigneter Lebensräume für den Goldschakal zu erstellen, um mehr über den Lebensraum und die Höhenverteilung der Art zu erfahren. Zusätzlich soll die Interaktion der drei Caniden durch Interpretation von Artnachweise und Fotofallen Bildern erforscht werden. Der geeignete Lebensraum wurde mit Maxent modelliert. Dazu wurden Artnachweise für alle Säugetiere in der Region mit drei verschiedenen Methoden gesammelt. Zu einem existierenden Datensatz (2010-2018) wurden für den Goldschakal 2019 neue Daten durch akustische Stimulation hinzugefügt. Außerdem wurden Artnachweise durch Snow & mud tracking und Fotofallen gesammelt. Der geeignete Lebensraum für Goldschakale scheint vor allem entlang von Flussläufen, in Wäldern der collinen und montanen Höhenstufe und in Gebieten extensiver Landwirtschaft zu finden zu sein. Dabei scheinen die sandigen Schotterbänke entlang von Flüssen von außerordentlicher Bedeutung zu sein. Das Modell zeigt, dass große Teile der Region, vor allem im Flachland in der Mitte der Region und in den Bergtälern des Nordens geeignetes Habitat für den Goldschakal bereitstellen. Goldschakale wurden in signifikant niedrigeren Lagen gefunden als Wölfe und Füchse. Dort wo es reproduktive Wölfe in der Region gibt, haben die Goldschakale aufgehört auf die akustische Stimulation zu antworten, was ein Zeichen für Konkurrenz sein kann (Lapini et al. 2018). Die Ergebnisse der Fotofallen lassen nur eine Analyse in einem spezifischen Fall zu. Obwohl der Datensatz sehr klein ist, konnte die Tendenz gezeigt werden, dass Füchse zwar das gleiche Habitat nutzen, den Goldschakalen aber aus dem Weg gehen indem sie an unterschiedlichen Tagen anwesend sind. Weitere Studien sind nötig, um die Interaktion der drei Arten besser zu erforschen. IV TABLE OF CONTENT Acknowledgements .................................................................................................................... II Abstract ..................................................................................................................................... III Table of Content ......................................................................................................................... V 1 Introduction ........................................................................................................................ 1 1.1 Species Distribution Models (SDM) ............................................................................. 1 1.2 Carnivore Interaction ................................................................................................... 1 1.3 Research Question ....................................................................................................... 4 1.4 Description of the Target Species ................................................................................ 4 1.4.1 The Golden Jackal Canis aureus L., 1758 .............................................................. 4 1.4.2 The Grey Wolf Canis lupus L., 1758 ...................................................................... 8 1.4.3 The Red Fox Vulpes vulpes L., 1758 .................................................................... 10 2 Material and Methods ...................................................................................................... 12 2.1 Study Area.................................................................................................................. 12 2.1.1 Geography .......................................................................................................... 12 2.1.2 MA1: Cansiglio .................................................................................................... 13 2.1.3 MA2: Magredi ..................................................................................................... 13 2.1.4 MA3: Carnia/Upper Tagliamento ....................................................................... 14 2.1.5 MA4: Middle Tagliamento .................................................................................. 14 2.1.6 MA5: Lower Tagliamento ................................................................................... 14 2.1.7 MA6: Val Aupa/Glazzat ...................................................................................... 15 2.1.8 MA7: Julian Pre-Alps/Natisone .......................................................................... 15 2.1.9 MA8: Torre ......................................................................................................... 15 2.1.10 MA9: Goritian Karst & MA10: Trieste Karst ......................................................