Vulnerability of moose and roe deer to wolf predation in Scandinavia - does habitat matter?

1. Study area showing the 11 wolf territories on the Scandinavian Peninsula. Material and Method Habitat features were compared at sites where wolves killed moose and roe deer, with sites 500 m from kills (control sites) and with sites randomly distributed within territories. The choice of habitats, kill sites, and their landscape features were investigated. Kill sites were visited in the field and classified according to a number of physical and vegetation characteristics during the summer of 2006. The same sites were the analyzed on a larger scale using different layers in GIS. Kill sites were compared to control and randomly distributed sites and statistical models were constructed in order to identify habitat characteristics that were significantly related to kill sites. Vulnerability of moose and roe deer to wolf predation in Scandinavia- does habitat matter? Contact Lisette Fritzon lisette_fritzon@hotmail.com http://cms.ifm.liu.se/edu/biology/master_projects/2007/lisette-fritsson/ Applied Biology International Master Programme Dep. of Biology, IFM, University of Linköping Acknowledgements First of all I would like to thank my supervisors Håkan Sand, Camilla Wikenros, Grimsö Wildlife Research Station, and Mats Amundin, Kolmården Zoological Park, for guiding me through this project. Many thanks to my two field assistants Sabrina Muller and Undine Knappwost and to my dog Sam for always being by my side. Grzegorz Mikusinski was very helpful and encouraging during all hours of working with Arc View. Thank you all for making this thesis possible! For more information about wolf projects http://grimso.nvb.slu.se www.wolf.org/wolves/index.asp

2. Introduction Wolves (Canis lupus) are known to prey on a variety of different animal species and in most areas ungulates are by far the most important prey. Due to several factors, such as absence of natural predators, changes in forestry practice and harvest strategies, the Scandinavian moose (Alces alces) and roe deer (Capreolus capreolus) populations has experienced a dramatic growth during the last 50 years. Economically, moose became an important species, both for hunters and for forestry production. This started a debate about how to regulate and manage the moose population. Little research has been done so far on the effects in large mammal predator–prey systems of habitat alternation. In order to meet objectives for populations of both predators and prey, more knowledge of how habitat and spatial factors may affect the vulnerability of prey is needed and will provide wildlife managers with knowledge how to manage habitats and landscapes in the most efficient way. The aim was to examine if there are high-risk areas for moose and roe deer in a wolf territory. Result 1. Field reconnaissance * Height of undergrowth, proportion of meadow, proportion of spruce → higher at moose kill sites compared to control sites * Average meters above sea level→ lower at moose kill sites compared to control sites * Number of stems →higher at roe deer kill sites compared to control sites 2. Geographic spatial analysis * Proportion clear-cuts, number of buildings, average meters above sea level → lower at moose kill sites compared to random sites * Average meters above sea level → lower at roe deer kill sites compared to random sites * Proportion coniferous forests → higher at roe deer kill sites compared to random sites Discussion Insights into the mechanisms of predation and habitat selection may have important management and conservation implications. Habitat selection allows animals to reduce the potential effect of limiting factors. Identifying the limiting factors should allow a better understanding of variations in habitat selection patterns across seasonal and daily periods. This could also lead to better predicting impacts of wolves on prey and in enhancing conservation of wolves. Predation, food ability, climate, parasites and disease are the most important natural factors that can potentially limit moose and roe deer populations. Conclusion Moose and roe deer are selective in their choice of habitat. There are patterns in which habitats moose and roe deer are being killed by wolves, meaning that habitat does matter. Further research More studies are needed, one way forward could be to use GPS radio collars on both wolves and moose/roe deer that record their locations at intervals over two winters and summers. The aim would be to test whether moose/roe deer locations differs on days when wolves are present or absent. With this test the advantage is that the movements of wolves can be used to test the behavioural responses by resident moose/roe deer.