Monitoring of the Western Capercaillie (Tetrao urogallus) population in Šumava

Researchers: RNDr. Luděk Bufka, Ing. Tomáš Lorenc

The remaining population of the Western Capercaillie in Šumava is currently the only viable population in Bohemia; about 90% of the estimated numbers of the Capercaillie in the Czech Republic are found in Šumava (Málková et Lacina 2002). It also represents one of the few larger Capercaillie populations residing in medium altitude mountains in central Europe (Klaus et Bergmann 1994, Scherzinger 2003). The Capercaillie recently received more attention in Šumava, particularly in relation to long-term trends in the abundance and current status of the population (Bufka et al 2000, Rom 2000, Smrčková 2000), potential threats to the population and its protection from a European perspective, changes in habitats and the overall anthropogenic pressure on the territory. The evaluation of the projects for population enhancing through releasing young breeds was carried out by Scherzinger (1995, 2000) in Bavaria, and on the Czech side of the mountain by Hlavatá (2002).


Currently, a nationwide systematic inventory of the coverage is in place as well as the registration of all data in the whole of Šumava NP and PLA in order to intercept the current status of the population and to give more precise estimates of abundance. Verification of the status and availability of former and potential nesting locations is carried out, including registration of the occupancy and number of cocks and habitat conditions; the subject of the study is also to monitor the capercaillie response to changes in the structure of forest habitats in the central part of the mountains, which is the core area of occurrence, with respect to decay of the spruce tree floor due to a bark beetle catastrophe.

Overview of all data received used for partial assessment

Type of observationcocklekking callshenindirectnestchicksindependent chickscelkem
Period 1965 - 1996209237163126131617781
Period 1997-1999 (Smrčková 2000)12027109231424-515
Period  2000-200413233111274164327
Total4612973833842156211623

The core of the current spread of capercaillie in Šumava is in the central and western parts. These are mainly the central Modrava and Kvilda plains, the high altitudes of Železná Ruda highlands, including the upper basin of Křemelná. The entire ridge of the Royal forest is also an important refuge. On the other hand, the south east part of the mountains have only scattered occurrences of capercaillie. The bird rarely occurs in Boubín and the Želnavské highlands. Regular occurrences, including reproduction, have been repeatedly recorded since 2000 in the Trojmezenská highlands. Some observations in the vicinity of Strážný and Borové Lady are associated with the release of artificially bred birds, within the population strengthening project (Hlavatá 2002).
Nesting occurrence is greatly reduced at higher altitudes of 1,000 - 1,370 m.a.s.l., mostly occurring at 1,100 - 1,300 m.a.s.l. (see also Smrčková 2000). Regular nesting at lower altitudes is unique (inversion basin of upper Křemelná).
  

 


The habitat of the Capercaillie in the so-called interference free territory.The main types of habitat include climate spruce, waterlogged spruce forests and the upland and valley moors.
Estimates of the current population numbers are around 200 birds on the Czech side of Šumava. Since 1990, a slight increase in the population has been registered (Bufka et al 2000), which is reflected in the stable overall occurrence of the capercaillie in the territory. The relevant estimated density of the core area is 0.74 - 1.10, i.e. an average of 0.97 birds per 100 hectares.
The number of nesting cocks range from 1 to 7 between 2000 and 2004 (n = 20); the average is 2.8. The long-term average for the period between1965 and 2004 is 1.29 (1-7; n = 257). The onset of the lekking call is less clear-cut time wise; the end is regular and relatively sharply defined; i.e. it finishes in the last week of May. The earliest records of the lekking cocks are from the beginning of March (9.3. - 23.4., Ć 24.3.). The last lekking calls are recorded in the period from 20.5. - 6.6., Ć 24.5.
Finding nests full of eggs is rare and random (n = 9). The earliest finding of a nest containing laid eggs is recorded on 5th May, the latest on 18th of June. The number of eggs laid ranges from 6 - 10, the average is 7.33 (6,6,7,7,7,7,7,9,10).
Typical damage to a tree caused by browsing in the early spring. For their lekking calls the cocks usually choose
the open-canopy of an old tree or
the edges.

Hatching roughly falls into the second half of June (n = 30). The chicks mostly appear around 15.6. (1988 - hen with 6 chicks, Valečka in litt.).
The number of chicks observed with hens was as follows: 3 - 12; Ć 4.64 (n = 14, 1965 - 1996), 1-12; Ć 5.93 (n = 16, 1997 - 2004) and 1-12; Ć 4.93 (n = 30) for the period 1965 - 2004.
The relatively high number of observations, as well as the high numbers of chicks successfully let out of the nests, demonstrates relatively successful reproduction over the last 4 years. A positive trend is the slight expansion of occurrence territories. This corresponds with the higher estimates of abundance according to the reports in various hunting grounds (for example, based on the data provided by individual forest administrations of Šumava National Park from the 1st half of 2004, the total estimate was 196 to 244 birds).





Map - the spread of Capercaillie according to data provided by the Administration of Šumava NP
Observation of Capercaillie
Šumava National Park
Šumava PLA

Literature

Bufka L., Červený J, Bürger P., 2000: Vývoj početnosti tetřeva hlušce (Tetrao urogallus) na Šumavě. In: Málková P (Ed.): Tetřevovití - Tetraonidae na přelomu tisíciletí. Sborník příspěvků z mezinárodní konference 24.-26.3.2000 v Českých Budějovicích: 52-57.

Hlavatá A., 2002: Ekologie tetřeva hlušce (Tetrao urogallus). Diplomová práce, přírodovědecká fakulta UK Praha, m.s., 95 pp. + přílohy.

Klaus S., Bergmann H.-H., 1994: Distribution, status and limiting factors of capercaillie (Tetrao urogallus) in Central Europe. Cibier Faune Sauvage 11 (special number part 2): 57-80.

Málková P., Lacina D., 2002: Important bird areas in the Czech republic. Česká společnost ornitologická, Praha, 144 pp.

Smrčková T., 2000: Současný stav populace tetřeva hlušce na Šumavě. Diplomová práce, lesnická fakulta ČZU Praha, m.s., 81 pp. + přílohy.

Scherzinger W., 2003:Artenschutzprojekt Auerhuhn im Nationalpark Bayerischer Wald von 1985 - 2000. Nationalpark Bayerischer Wald, Grafenau,130 pp.

Scherzinger W., 1985: :Artenschutzprojekt Auerhuhn im Nationalpark Bayerischer Wald, berichtzeitsraum 1985 -1995. Nationalpark Bayerischer Wald, Grafenau, 77 pp.



 
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