SYLVIA 39 / 2003 SUPLEMENT

Maintaining Black Grouse wintering habitats by Alpine pasture management plans

Albin Zeitler

Rothenfelsstr. 7, D-87509 Immenstadt, Germany; e-mail: [email protected]

Zeitler A. 2003: Maintaining Black Grouse wintering habitats by alpine pasture management plans. Sylvia 39(suppl.): 97–102.

Alpine pasture management is a key factor for preserving much of the present Black Grouse (Tetrao tetrix) habitat in the German Alps. Dwarf Pine (Pinus mugo) and Green Alder (Alnus viridis) that commonly cover parts of the pastures are preferred Black Grouse winter foods. Sporadic removal of these shrubs is common practice to maintain pasture extent and quality. This is increasingly done at a large scale, and pastures loose suitability for Black Grouse, par- ticularly during times of high snow layers. To secure Black Grouse winter habitat capacity, pasture management plans can be developed maintaining Dwarf Pine and Green Alder in places accessible to the birds throughout the winter. At display sites, however, removal of regenerating trees that appear to favour predation may help to increase Black Grouse survival. In Black Grouse friendly pasture management, the spatio-temporal patterns of Black Grouse habitat availability as well as orography, aspect, local wind systems, but also skiing and winter hiking routes need to be considered.

Keywords: Alps, Alpine pastures, Black Grouse, conservation, management, Tetrao tetrix, winter habitat

INTRODUCTION Today, these secondary habitats are at The management of alpine pastures is risk: Declining use and maintenance of a key factor for preserving most of the alpine pastures leads to declining Black present Black Grouse (Tetrao tetrix) Grouse populations (Glänzer 1985), as habitats along the northern edge of the has been documented in various parts eastern Alps. Naturally, Black Grouse of the Alps. Regionally, however, intensi- would be restricted to subalpine habi- fication of pasture management and the tats along treeline. The long history of replacement of manual labour by handy pasturing, however, has greatly extend- machinery appear to negatively affect ed open habitats suitable for Black Black Grouse habitats. Dwarf Pine Grouse into potentially forested areas of (Pinus mugo) and Green Alder (Alnus the montane zone. In the Bavarian Alps, viridis), the preferred winter foods, are Germany, and their foothills with eleva- increasingly removed at a large scale. In tions below 1800 m in particular, Black consequence, pastures loose much of Grouse habitat capacity depends on their capacity as Black Grouse winter pasture management practices such as habitat. grazing, mowing, and sporadic removal In this paper, I describe the relation- of regenerating trees and shrubs. ship between Black Grouse and Alpine

97 Zeitler A. / Black Grouse wintering habitats pastures in the Bavarian Alps. I suggest Alps. Until today, in each of 12 approxi- considering spatial and temporal avail- mately 30,000 ha large study areas, field ability of Black Grouse winter feeding observations of Black Grouse and Black patches and display sites in alpine Grouse signs, and mapping of habitats pasture management plans, particularly and human activities were conducted in in the removal of shrubs and tree regen- about 140 observation days during two eration, in order to maintain and successive winters. In a few additional improve carrying capacity for Black intensive study areas in the westernmost Grouse. part of the Bavarian Alps (Oberallgäu district), I conducted monthly to weekly METHODS Black Grouse observations and took monthly to weekly photographs of Study area winter habitats throughout the winter period (October to May) over several The Bavarian Alps are the German, nort- years since 1989. hernmost part of the Alps and spread Also in the Oberallgäu, I visited 44 over about 5,000 km2 along the Austrian Black Grouse „leks“ (both communal border (10–13°E; 47°16’–50’N). The and solitary display sites) 1–4 times climate is moist and temperate with each May/June between 2001 and 2003. mean annual temperatures of about I counted displaying males and meas- 5 °C, mean annual precipitation of ured the diameter (m) of the open area 1,500–2,200 mm, wet summers and available at and around a lek, and the snow-rich winters. The peaks reach maximum distance (m) of any point on elevations between 1,000 and 3,000 m the lek to the closest spruce trees, that above sea level; the valleys at may serve as cover for approaching 600–1,000 m are densely populated and Golden Eagles (Aquila chrysaetos) or used for intensive dairy farming. Mon- Red Foxes (Vulpes vulpes), or as a perch tane and subalpine mixed and conifer- for Goshawks (Accipiter gentilis). ous forests cover major parts of the During one close inspection of each lek slopes. Above the tree line between per year, I noted remains of Black 1,300 and 1,800 m, grassland intermixed Grouse killed by predators. with patches of Dwarf Pine and rocks and gravel prevails. RESULTS Background and database The background and database of this Black Grouse and alpine pastures paper are 15 years of field experience in in the Bavarian Alps the Bavarian Ministry of Environ- The Black Grouse is a threatened ment’s project „Skiing and Wildlife“ that species in Germany (Lindström et al. aims at reducing disturbance of Black 1998). The largest population, estimated Grouse and other species by skiing and at a few thousand birds (Table 1), inhab- other winter sport activities (Zeitler its the Bavarian Alps, however, long- 1995, Zeitler & Glänzer 1998), and term persistence probably depends on various other management projects connectivity with the Austrian Alps related to human disturbance of Black (Segelbacher & Storch, unpubl. data; see Grouse habitats (e.g., Zeitler 2000). also Segelbacher et al., this volume). The ongoing project „Skiing and There is no grouse monitoring system in Wildlife“ covers the entire Bavarian Bavaria, and records of displaying males

98 SYLVIA 39 / 2003 SUPLEMENT collected by the state agencies are Their central role in alpine folklore is generally unreliable. No pronounced a major reason why pastures are still changes in overall Black Grouse popula- maintained today, although in many tion levels were noted during the past 15 areas, they are no longer economically years, but local declines appeared likely sustainable. Present-day alpine agricul- (Zeitler 1995, Zeitler & Glänzer 1998, ture is heavily subsidised for the mainte- Zeitler 2000, own unpubl. data). Main- nance of open pastures. taining Black Grouse in the Bavarian At present, there are two major trends Alps is an official conservation goal. in Alpine pasture management in Primary Black Grouse habitats in the Bavaria: (1) pastures are intensified by Bavarian Alps are restricted to subalpine large-scale removal of tree and shrub habitats along treeline. Centuries of regeneration and application of fertiliz- alpine pasturing, however, have lowered ers; and (2) pastures difficult to access the treeline almost everywhere and are given up to natural succession. Both created additional, secondary Black trends partly or totally reduce habitat Grouse habitats of significant extent in suitability for Black Grouse. Declining the montane zone by transformation of maintenance of alpine pastures leads to forests into open grassland. According declining Black Grouse populations as to official records, 1341 alpine pastures a consequence of secondary habitat are maintained in Bavaria (Table 2). loss (Glänzer 1985). Intensification of

Table 1. Some data on the extent of Black Grouse habitats and estimated Black Grouse popu- lation numbers in the Bavarian Alps, Germany, 2003. Numbers are tentative estimates of average population density (2–3 cocks/100 ha; sex ratio 1:1) and reproductive success during 1990–2003, based on own field experience. No marked fluctuations in population densities were noted; however, note that a standardised monitoring system of grouse populations is lacking in Bavaria.

Black Grouse in the Bavarian Alps 2003 Total area managed as pasture 40,600 ha Former pastures out of use and Black Grouse 20,000 ha habitats other than pastures Black Grouse habitat total 60,000 ha Black Grouse spring population densities 0.5-4.0 / 100 ha Estimated n cocks in spring 1,200–1,800 Estimated n hens in spring 1,200–1,800 Estimated spring population 2,400–3,600

Table 2. Some data on the extent and use of Alpine pastures in the Bavarian Alps, Germany, 2003 (data from Hinterstoisser 2003).

Alpine pastures in the Bavarian Alps 2003 Extent Alps and Pre-Alps in Bavaria 500,000 ha Number of pastures 1,341 Total area managed as pasture 40,600 ha Number of cattle on alpine pastures 47,849 Number of horses on alpine pastures 640 Number of sheep and goats on Alpine pastures 3,770

99 Zeitler A. / Black Grouse wintering habitats pasturing, on the other hand, may result June, however, Black Grouse preferably in a significant loss in winter habitat use exposed, open sites such as hilltops capacity by reduced availability of or ridges (Lindström 1998). Of a total of winter feeding patches. 44 Black Grouse leks in Oberallgäu district, 28 were classified as “small” Black Grouse winter and lek display sites, defined as ≤100 m in diame- habitats ter and ≤50 m from spruce trees or the The Black Grouse is a species that relies forest edge, whereas the remaining 16 on heterogeneous habitat mosaics (see “large” sites measured ≥300 m in diame- review by Lindström et al. 1998), rather ter and were in distances of ≥150 m from than a single vegetation type. Key spruce trees. Black Grouse killed by elements of good Black Grouse habitat predators were found on 17 of the 28 in the Bavarian Alps are grassland inter- small display sites. These were eight soli- spersed with patches of Dwarf Pine and tary cocks on display sites 10–100 m in Green Alder, lines or patches of spruces, diameter, five cocks from sites with 1 or patches of ericaceous shrubs, tall 2 displaying cocks (20–100 m diameter), grasses, and wet flushes with tall herbs. and four cocks from leks with 3–7 Densities tend to be greatest where displaying males (40–100 m). Kill these elements are well interspersed at remains indicated that both raptors scales of hectares and below. On extend- (probably Golden Eagle, Goshawk) and ed open pastures in the Oberallgäu area, mammalian predators (probably mostly for example, the planting of Green Red Fox) were involved. However, no Alder patches to prevent erosion was kills were found on any of the 16 large followed by a remarkable increase of leks. These preliminary findings suggest local Black Grouse observations. that extended open spaces as display Winter appears to be a bottleneck sites offer predators fewer chances than season for Black Grouse in the Bavarian small sites with less overview (see also Alps. Accessibility of their winter food Keulen et al. 1997, Keulen et al. 2000, shrubs of Dwarf Pine and Green Alder Müller 2000). Here, Black Grouse males varies with snow conditions, and few were not necessarily killed only during patches remain during maximum snow display activity, but also during feeding depth of several meters in mid to late and resting behaviours that can often be March. For example, in a 500-ha area of observed on or in close vicinity of Oberallgäu, of the 32 feeding patches of display sites at any time of day. Black Grouse that were counted in early November, more and more of them Pasture management for Black became inaccessible as the snow accu- Grouse conservation mulated, and only a few remained acces- Alpine pasture management could signi- sible throughout the winter. The ficantly contribute to Black Grouse patches that are most likely to remain conservation, if pasture maintenance accessible are the same year after year; activities would aim at maintaining the shrubs are tall enough and/or they a favourable habitat mosaic. In particu- grow in places where high snow layers lar, the removal of shrubs could improve cannot accumulate due to local topog- Black Grouse habitat quality by taking raphy and wind system. into account: (1) Life-history characteris- For their collective display towards tics and habitat needs of Black Grouse the end of the snowy season in April to in winter (winter habitat capacity), and

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(2) preferences of Black Grouse to (Segelbacher & Storch unpubl. data). display collectively on extended open Thus, in order to maintain a viable popu- spaces, rather than close to trees that lation of Black Grouse in Bavaria, further appear to increase predation risk. In declines in habitat quality and carrying addition, orography, aspect, and local capacity must be prevented. Black wind systems, but also skiing and winter Grouse friendly pasture management is hiking routes need to be considered. therefore an important prerequisite for In the process of alpine pasture the persistence of the population. management planning, the spatio- Within the framework of Alpine temporal availability of Black Grouse pasture management in the Bavarian winter food and display sites need to be Alps, and particularly through the sporad- mapped. To maintain a diverse mosaic ic removal of shrubs and regenerating favourable for Black Grouse, succession trees in order to maintain pasture extent of pastures into extended fields of and quality, a heterogeneous habitat Dwarf Pine, Green Alder thickets, or mosaic favourable for Black Grouse forest must be prevented. At the same could be maintained. This would not time, larger-scale total removal of all require major changes in current man- woody vegetation including trees, agement practices applied by cattle bushes, and ericaceous shrubs, as keepers, except for local modification in commonly practiced in areas with high spacing and timing, but not extent, of livestock numbers and intensive clearing operations. Initially, pasture grazing, has negative effects on Black management plans could easily be Grouse habitat suitability and carrying developed in co-operation with wildlife capacity. In order to maintain and ecologists and conservation agencies; in improve winter habitats for Black the long run, however, cattle keepers Grouse, none of those Dwarf Pine and themselves should be able to develop Green Alder patches that remain acces- Black Grouse friendly management sible throughout winter must be cut. plans under the supervision of district Alpine pasture management may conservation agencies. In contrast to contribute to reduce Black Grouse many other Black Grouse areas, where mortality from predation on leks by habitat management is costly, a great maintaining open spaces at preferred advantage in the Bavarian Alps is that display sites that allow good overview. additional expenses, i.e., those exceed- ing normal pasture management costs DISCUSSION for the sake of Black Grouse conserva- Black Grouse in the Bavarian Alps tion, will remain negligible. appear to be distributed in a metapopu- First experience with introducing lation pattern (Storch & Segelbacher these ideas in the management opera- 2000, Segelbacher & Storch unpubl. tions of a few pastures in the Bavarian data), and their viability may strongly Alps indicate that cattle keepers and depend on connectivity with popula- their organizations welcome sugges- tions in Austria. In Capercaillie, popula- tions to integrate Black Grouse habitat tions at the edge of the alpine distribu- conservation aspects into Alpine pasture tion range show sink characteristics management. (Segelbacher et al. 2003a, b, Storch & It is important to note, however, that Segelbacher 2000); in Black Grouse, favourable structures are not the only the situation appears to be similar aspect of habitat suitability for Black

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Grouse. The Bavarian Alps are among Der Almbauer (Almwirtschaftlicher the most heavily frequented recrea- Verein Oberbayern) 55: 4–5. tional areas of Europe. At a regional Keulen C., Houbart S. & Ruwet J. C. 1997: Les scale, there is not a single mountain arènes de parade des Tétras lyres (Tetrao ) dans les Hautes-Fagnes de range or Black Grouse area not used for tetrix Belgique: caractéristiques paysagères et ski touring, snow-boarding, downhill propositions de gestion. Cahiers skiing, or snow-shoeing (Zeitler & d’Ethologie 17 (2–3–4): 387–529. Glänzer 1998, Zeitler 2000). In addition, Keulen C., Houbart S. & Ruwet J. C. 2000: most pastures have huts traditionally Arenas landscape features inside the used by cattle herders over the summer Black Grouse habitat in the Belgian months; today, many of these are used Hautes-Fagnes. In: Actes du Colloque as private holiday and weekend homes, Tétras lyre: The Fate of Black Grouse and some have been developed (Tetrao tetrix) in European Moors and Heathlands. into tourist restaurants or hostels. Cahiers d’Ethologie 20 (2–3–4): 509–520. To limit the negative consequences of Lindström J., Rintamäki P. T. & Storch I. 1998: sports and leisure activities for Black Grouse. BWP Update 2: 173–191. Black Grouse and other wildlife is an Müller F. 2000: Beobachtungen zur „Terri- important concern of Bavarian torialität“ von Birkhähnen auf einem conservationists. These disturbances traditionellen Balzplatz in der Hessischen and their direct and indirect consequen- Hochrhön. Cahiers d’Ethologie 20 (2–3–4): ces need to be considered in Black 333–352. Grouse friendly Alpine pasture man- Segelbacher G., Storch I. & Tomiuk J. 2003a: Genetic evidence of Capercaillie dispersal agement. sources and sinks in the Alps. Wildlife Biology 9 (in press). ACKNOWLEDGEMENTS Segelbacher G., Höglund J. & Storch I. 2003b: From connectivity to isolation: genetic The experience I report here partially consequences of population fragmenta- resulted from my work for the project tion in Capercaillie across Europe. Mol. „Skilauf und Wildtiere im Gebirge“ Ecol. 12: 1773–1780. (Skiing and Wildlife in the Mountains) Storch I. & Segelbacher G. 2000: Genetic of the Bavarian State Ministry of the correlates of spatial population structure Environment. I thank Ulrich Glänzer for in central European Capercaillie and initiating this exceptional, long-term Black Grouse: a project in progress. and large-scale project. Wildlife Biology 6: 239–243. Zeitler A. 1995: Skilauf und Rauhfusshühner. Ornithol. Beob. 92: 227–230. Zeitler A. 2000: Human disturbance, behav- LITERATURE iour and spatial distribution of Black Glänzer U. 1985: Effects of land use changes Grouse in skiing areas in the Bavarian on bird life, example: Tetrao tetrix and Alps. Cahiers d’Ethologie 20 (2–3–4): Lagopus lagopus. Transactions Congress 381–400. International Union Game Biologists 17: Zeitler A. & Glänzer U. 1998: Skiing and 501–507. grouse in the Bavarian Alps. Grouse News Hinterstoisser M. 2003: Bedeutung und (Newsletter of the IUCN Grouse Specialist Herausforderung der Berglandwirtschaft. Group) 15: 8–12.

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