Genetic structure of capercaillie populations: a non-invasive approach at multiple spatial scales Gernot Segelbacher Fachgebiet Wildbiologie und Wildtiermanagement Genetic structure of capercaillie populations: a non-invasive approach at multiple spatial scales Gernot Segelbacher Vollständiger Abdruck der von der Fakultät Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt der Technischen Universität München zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigten Dissertation. Vorsitzender: Univ.-Prof. Dr.forest. Gerhard Müller-Starck Prüfer der Dissertation: 1. Univ.-Prof. Dr.forest. Dr.rer.silv.habil. Wolfgang Schröder 2. apl.Prof. Dr.agr. Dr.agr.habil. Oswald Rottmann Die Dissertation wurde am 29.01.2002 bei der Technischen Universität München eingereicht und durch die Fakultät Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt am 25.04.2002 angenommen. Sebastién Sachot We only preserve what we love, we only love what we understand, we only understand what we study. Tibetan Saying Results! Why, man, I have gotten a lot of results. I know several thousand things that don´t work. Thomas A. Edison Table of Contents 0 Preface…………………………………………………………………. 1 1 Introduction…………………………………………………………… 4 2 General Methods……………………………………………………... 7 3 Analytical advances…………………………………………………. 13 3.1 Characterisation of microsatellites………………….……………... 13 3.2 Bird faeces for genetic analysis……………………………….…… 16 3.3 Non-invasive sampling: testing reliability…………………..……… 21 4 Population genetics of capercaillie……………………………….. 26 4.1 Genetic diversity across Europe………………….……………….. 26 4.2 Metapopulation structure in the Alps…….…………………….….. 38 4.3 Source-sink populations…….……………..……………………….. 55 5 Conclusions…………………………………………………………… 68 6 Summary………………………………………………………………. 72 7 References…………………………………………………………….. 77 8 Acknowledgements………………………………………….………. 89 9 Appendix……………………………………………………………….. 91 0 Prefac e 0 Preface The general framework of this thesis is given by the introduction (chapter 1). General methods are described in chapter 2. I subdivide this thesis into six papers, which address different aspects of analytical advances with non-invasive genetic sampling in birds (chapter 3) and population genetics of capercaillie (chapter 4). In chapter 3.1 I describe the development of microsatellites for capercaillie and their use for this study. Thereafter, I describe the methodology of using bird faeces samples for genetic studies (chapter 3.2). Subsequently, I stress the reliability of feather samples for population genetic studies (chapter 3.3). This sets the frame for the following papers, treating the genetic variation of capercaillie at multiple spatial scales (chapter 4). In Chapter 4.1 I analyse the genetic diversity of capercaillie across Europe and demonstrate the importance of connectivity among populations. I hypothesise that capercaillie populations in the south-west, i.e. western and central Europe, will reveal a more structured genetic signature than birds from different sites within the contiguous and relatively undisturbed northern parts of the range, i.e. Fennoscandia and Russia. I assume genetic diversity to be lower in the Pyrenees and in small isolated populations in central Europe than in more contiguous populations in the Alps and northern Europe. The following chapter 4.2 deals with the metapopulation structure in the Alps. I analyse the spatial pattern of genetic variation in the Alps, testing the metapopulation hypothesis for those populations. I compare the genetic structure of populations along the northern edge of the Alpine distributional range with populations from other parts of the Alps. In the final chapter 4.3 I focus on fine-scale patterns of gene flow and genetic diversity. I attempt to assess how habitat availability might influence genetic population structure and demonstrate source-sink dynamics in a metapopulation framework. For each of these chapters I provide an abstract and introduction, describe methods and present and discuss results. The Conclusion (chapter 5) summarises the major findings of the previous chapters and points out consequences of these findings for capercaillie conservation and management. 1 0 Preface The main chapters of this thesis have been published or submitted for publication to scientific journals with the following authorships and titles: Segelbacher G, Paxton R, Steinbrueck G, Trontelj P, Storch I (2000) Characterisation of microsatellites in capercaillie (Tetrao urogallus) (AVES). Molecular Ecology, 9,1934-1935. (Chapter 3.1)1 Segelbacher G, Steinbrück G (2001) Bird faeces for sex identification and microsatellite analysis. Vogelwarte, 41, 139-142. (Chapter 3.2) Segelbacher G (in press) Non-invasive genetic analysis in birds: testing reliability. Molecular Ecology Notes. (Chapter 3.3)1 Segelbacher G, Höglund J, Storch I (submitted manuscript) Variation in genetic diversity across the European range of capercaillie (Tetrao urogallus). (Chapter 4.1) Segelbacher G, Storch I (submitted manuscript) Metapopulation structure of capercaillie (Tetrao urogallus) in the Alps. (Chapter 4.2) Segelbacher G, Tomiuk J, Storch I (submitted manuscript) Source and sink populations in Alpine capercaillie: evidence from microsatellites. (Chapter 4.3) 1 Papers are reprinted with the permission of the publisher. © Blackwell Science 2000, 2002 All others © Gernot Segelbacher 2002 2 0 Prefac e Parts of this thesis have also been presented in the following papers: Segelbacher G, Storch I (1999) Genetic markers for studying spatial structure of grouse populations. Grouse News (Newsletter of the IUCN Grouse Specialist Group) 18, 4-8. Segelbacher G, Storch I (1999) Comparison of geographic and genetic distance in grouse (abstract). 2nd International Wildlife Management Congress, Gödöllö, Hungary. Segelbacher G, Storch I (1999) Geographic and genetic distance in European grouse (abstract). 8th International Grouse Symposium, Rovaniemi, Finland. Segelbacher G, Höglund J (2000) Conservation of black grouse – a study using microsatellites. Cahiers d'Ethologie, 20, 411-420. Segelbacher G, Storch I (2000) Welche Möglichkeiten bieten genetische Marker im Naturschutz ? Zusammenhang zwischen geographischer und genetischer Distanz bei Rauhfußhühnern (abstract). 150. Jahrestagung der DO-G in Leipzig. Journal für Ornithologie, 142, 215. Segelbacher G, Storch I (2000) Spatial distribution and genetic differentiation of black grouse populations in the Alps: preliminary results from a study with microsatellite markers. Workshop on the fate of black grouse (Tetrao tetrix) in European moors and heathlands, (abstract). Liège, Belgium. Storch I, Segelbacher G (2000) Genetic correlates of spatial population structure in central European capercaillie Tetrao urogallus and black grouse Tetrao tetrix: a project in progress. Wildlife Biology, 6, 305-310 Segelbacher G, Storch I (2001) Möglichkeiten molekularer Methoden im Naturschutz – am Beispiel des Auerhuhns (abstract). Workshop der LWF. Segelbacher G, Storch I (2001) Spurensuche im Gebirge - was wir mit molekularen Methoden über Rauhfußhühner erfahren (abstract). 134. Jahresversammlung DO-G, Schwyz, Schweiz. Segelbacher G, Storch I (2001) Genetic differentiation of capercaillie in Europe – a non-invasive approach (abstract). 8th Congress of the European Society of Evolutionary Biology, Aarhus, Denmark. Segelbacher G, Storch I (2001) Population genetics of capercaillie and black grouse in the Alps (abstract). Conservation genetics meeting. Lausanne, Switzerland. 3 1 Introduction 1 Introduction The landscape of central Europe is dominated by farmland. Forests are distributed as isolated fragments within a matrix of open land; small woodlots no more than a few hectares in size prevail. Contiguous forests covering several hundred km² are restricted to mountainous regions. These are the areas where most of the remaining capercaillie (Tetrao urogallus) populations are found. Capercaillie are coniferous forest obligates. They prefer extensive areas of forest with moderate canopy cover and rich ground vegetation, dominated by ericaceous shrubs such as bilberry (Vaccinium myrtillus). In their boreal distribution range, capercaillie live in contiguous forest landscapes. In central Europe, however, grouse habitats, and thus populations, are spatially structured at two hierarchical levels of scale: forest-dominated uplands versus farmland-dominated lowlands at the continental scale (i.e. central Europe), and forested mountain slopes versus open habitats at the regional scale (e.g. in the Alps) (Klaus & Bergmann 1994). As a consequence, distribution ranges of grouse are separated by up to 100 and more km at the continental scale (see Klaus & Bergmann 1994), and local populations by up to 10 and more kilometre at the regional scale (I. Storch unpubl. data). From this distribution pattern, metapopulation structure has been hypothesised for central European capercaillie populations (see Rolstadt 1991, Storch 1993, 95, 97). The distribution of capercaillie has always been fragmented in central Europe after the last Ice Age due to the naturally patchy distribution of suitable habitats. However, the degree of fragmentation and the properties of both habitat patches and surrounding matrix have been altered by human land use practices. In general, habitat conditions are assumed to have deteriorated for capercaillie in the course of the 20th century (Storch 2001), and grouse populations may have been shifting towards decreasing