aleksandras stulginskis university lithuanian …the dissertation is available at martynas mažvydas...
TRANSCRIPT
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ALEKSANDRAS STULGINSKIS UNIVERSITY
LITHUANIAN RESEARCH CENTRE FOR AGRICULTURE
AND FORESTRY
Rytis Zizas
THE INFLUENCE OF FOREST STRUCTURE ON THE CAPERCAILLIE
(TETRAO UROGALLUS L.) HABITATS AND DISTRIBUTION IN SOUTH-
EASTERN BALTIC SEA REGION
Summary of doctoral dissertation
Agricultural sciences, Forestry (04 A)
Akademija, 2015
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The doctoral dissertation was prepared at the Institute of Forestry, Lithuanian
Centre for Agriculture and Forestry in 2009-2014.
Scientific advisor:
Prof. dr. Gediminas Brazaitis (Aleksandras Stulginskis University, Agricultural
Sciences, Forestry 04 A);
The dissertation will be defended at Forestry Board of Lithuanian Research
Centre for Agriculture and Forestry and Aleksandras Stulginskis University:
Chairman:
Members:
Prof. dr. Vitas Marozas
Dr. Virgilijus Baliuckas
Opponents:
Dr. Rimgaudas Treinys
Dr. Marek Metslaid
The official defence of the dissertation will be held on April 1, 2015 at 10 a.m., in
4th building, meeting room 211, Aleksandras Stulginskis University.
Address: Universiteto st.11, Akademija, 53361 Kaunas district, Lithuania.
Summary of the doctoral dissertation was sent out on March 31, 2015
The dissertation is available at Martynas Mažvydas National Library of Lithuania
and libraries of Aleksandras Stulginskis University and Institute of Forestry,
Lithuanian Research Centre for Agriculture and Forestry
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LIETUVOS AGRARINIŲ IR MIŠKŲ MOKSLŲ CENTRAS
Rytis Zizas
MIŠKO STRUKTŪROS ĮTAKA KURTINIŲ (Tetrao urogallus L.)
BUVEINIŲ PASIRINKIMUI IR PASISKIRSTYMUI BALTIJOS JŪROS
PIETRYČIŲ REGIONE
Daktaro disertacijos santrauka
Žemės ūkio mokslų sritis, miškotyros mokslo kryptis (04 A)
Akademija, 2015
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Disertacija rengta 2009–2014 m. Lietuvos agrarinių ir miškų mokslo centro filiale
Miškų institute.
Mokslinis vadovas:
Prof. dr. Gediminas Brazaitis – Aleksandro Stulginskio universitetas, Žemės ūkio
mokslų sritis, Miškotyros kryptis (04 A);
Disertacija bus ginama Aleksandro Stulginskio universiteto Miškotyros mokslo
krypties taryboje:
Pirmininkas:
Prof. dr.
Nariai:
Prof. dr. Vitas Marozas
Dr. Virgilijus Baliuckas
Oponentai:
Dr. Rimgaudas Treinys
Dr. Marek Metslaid
Disertacija bus ginama viešame Miškotyros mokslo krypties tarybos posėdyje 2015
m. ... .. d. 10 val. Aleksandro Stulginskio universiteto IV rūmų posėdžių salėje
(211 kab.).
Adresas: Universiteto g. 8A, Akademijos mstl. 53361 Kauno r.
Disertacijos santrauka išsiuntinėta 20... m. ...mėn. ... d.
Disertaciją galima peržiūrėti Nacionalinėje Martyno Mažvydo, Aleksandro
Stulginskio universiteto ir Lietuvos agrarinių ir miškų mokslų centro filialo Miškų
instituto bibliotekose.
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INTRODUCTION
The capercaillie densities have declined remarkably throughout its entire range,
especially in the past several decades (Wegge 1979; Miettinen, 2009). The species
is at the risk of extinction in the western, central and south-eastern Europe (Storch,
2007). For this reason, capercaillie is listed in Annex I of the EC Birds Directive
(Council Directive, 2009/147/EC), and the population trend appears to be
decreasing (IUCN, 2012; BirdLife International, 2015). Capercaillie has been listed
in the Red Data Book of Lithuania since 1989 (Rašomavičius, 2007) and attributed
to the rarity category II (critically endangered species). In accordance with Article
4 of the EC Birds Directive, Lithuania has established eight Special Protection
Areas (SPAs) for birds of this species.
Lithuania is located at the southwestern edge of a contiguous distribution range
of capercaillie. The species is fragmentary common in the southwestern part of
Europe. Therefore, it is necessary to ensure the protection of capercaillie habitats in
Lithuania avoiding the isolation of capercaillie populations. In addition, Lithuania
faces with stability problems of capercaillie leks (mating sites). Despite strong
fidelity and territoriality of capercaillie lek sites, leks tend to "move" or some areas
are abandoned by capercaillies and birds start using others leks. All known leks are
under protection in forests although birds have retreated and do not use them for a
long time. Changes in the forest structure could be one of the reasons why some
leks are eventually abandoned.
The abundance of birds depends on natural and anthropogenic factors, which
have certain influence at several spatial scale levels. Recent studies show that the
capercaillie, being a narrowly specialized and stand spatial structure demanding
species (Kurki and Lindén, 1995; Kurki et al., 2000; Graf, 2005), is sensitive to the
changes of macrohabitat at the landscape level. Various methods are used to
protect capercaillies in many countries as it is not known what particular features
of the habitat at the landscape level could create favourable conditions for
capercaillies. It is argued that capercaillies are one of the most thoroughly
researched species in western European countries (Storch, 2007); however, the
results may not always be adapted due to different geographical and ecological
conditions or forest management characteristics.
Biology and ecology of capercaillies were thoroughly studied in Lithuania by
Logminas more than fifty years ago (1962). Later, studies were mainly limited to
the identification of the location of capercaillie leks and monitoring of the
abundance of local populations in Special Protection Areas for birds and beyond.
Therefore, only a systematic and methodology based research can show the actual
condition of capercaillies (Kurtinio apsaugos planas, 2012). Until recently, there
were no detailed ecological studies, which would reveal the characteristics of
capercaillie habitats at both the level of stand structure (microhabitat) and
landscape (macrohabitat) level. The thesis mainly focuses on these two spatial
scale levels.
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The aims of the thesis were to identify the features of lek selection by
capercaillies, forest structure in habitats used seasonally and the dynamics of home
ranges depending on the time of the year.
The objectives of the research:
1. To evaluate the influence of forest landscape structure variables on the
occupancy of capercaillie leks and to assess regional forest structure
differences.
2. To identify variables influencing capercaillies leks selection and to
establish the significant distance.
3. To investigate the home range size of capercaillies and the distance from
leks these birds live at different time of the year.
4. To analyse forest structure in capercaillie microhabitats used at different
time of the year.
Defended statements:
The occupancy of capercaillie leks are affected by forest structure.
Capercaillies select places for lekking in unstocked mature pine stands
near wetlands.
The dynamics of home range size of capercaillie males is related to the
time of the year and the period of life.
Capercaillies use various habitats depending on sex and the time of the
year.
Scientific novelty and practical importance
Selection of leks by capercaillies has been analysed for the first time in
Lithuania and the dependence of lek occupancy on the structure of forest landscape
has been ascertaine Studies on the use and movement of capercaillie habitats by
applying radio telemetry method for individual birds have been carried out for the
first time in Lithuania and Belarus.
The biological characteristics, which were identified during the studies,
substantially supplement the theoretical knowledge about this species in the
southwestern edge of continuous range. The obtained results can be used for
further studies on the interaction of these birds with the environment. The obtained
data on the microhabitats use at different time of the year can be used to
supplement forest felling regulations, which regulate forest management
capercaillie lek protection areas. The obtained data on the needs of capercaillies for
leks helped and will help in future to find as-yet-unknown leks and to efficiently
plan capercaillie population protection in Lithuania.
Volume and structure of the work
The dissertation is written in the Lithuanian language. It consists of:
introduction, literature review, material and methods, results and discussion,
conclusions, further needs for research and study trends, proposals for capercaillie
protection, reference list, list of publications, list of abbreviations and annexes. The
dissertation consists of 119 pages, including 15 tables, 57 figures, 193 references
and 3 annexes.
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2. MATERIALS AND METHODS
2.1. Analysis of the influences of forest structure on the capercaillie leks
selection
Determination of leks and their occupancy level. The data on capercaillie
leks were obtained in 2008 conducting a questionnaire survey of employees of
state forest enterprises and regional and National parks. The locations, which were
indicated by the respondents, were adjusted to the data on the location of
capercaillie leks of State Forest Service (SFS). Seventy-one leks were chosen for
further investigation in total. Occupancy level and the location of lek centre were
determined as precisely as possible during the visits in March - April 2008-2012.
Lek occupancy level and lek centre were identified by seen/heard capercaillies,
and/or their activity signs. Leks were divided into ones of the high (≥2 males) and
low occupancy (attributed to individual male leks and non-used leks but still stored
in the SFS database). The new lek was distinguished, when it was >1000 m away
from the lek, including it in the SFS database. Whereas if the distance was ≤1000
m, the decision was made, that that was the same (continuous) lek (Rolstad and
Wegge, 1998a). GPS GARMIN device (the accuracy ±5 m) was used to record the
geographical coordinates of each lek centre. Forty-one leks (58 %) out of the total
71 capercaillie leks were attributed to the high occupancy leks, while 30 leks (42
%) were grouped as low occupancy leks. There were 21 leks of the high occupancy
(72 %) and 8 of low occupancy (28 %) in Dzūkija, while 22 leks of high
occupancy (52 %) and 20 (48 %) of low occupancy were distinguished in
Aukštaitija (Fig. 1).
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Fig. 1. The distribution of high- (black spots) and low-occupancy (white spots)
capercaillie leks in south-eastern Lithuania
A database of geographical locations of 71 capercaillie leks was created. Three
buffer zones, keeping a distance of 2-5, 5-10 and 10-20 km, were established
around each point, indicating the lek. Random points were generated within these
zones using ArcGIS random point generator. Circular restricted areas of 0.25 km
(represent 19.6 ha), 0.5 km (78.5 ha), 1 km (314.2 ha) and 2 km (1256.6 ha) radii
were established around the centre of each lek and random points. The variables of
the environment describing forest structure at the stand and landscape levels,
including human disturbance, were identified in these territories as follows:
distribution of stands by tree species; pine forest age; stocking level of the stands;
forest type; forest land; stands; forest depth; wetlands; drained wetlands; open
areas; density of the roads with pavement and distance to them; density of the
forest roads and distance to them; distance to forest edge and distance to a
homestead.
GDR10LT information from the Lithuanian Georeference GIS database
geographical and attribute data of forest department from the Lithuanian Forest
Cadastre (2010) were used for this research. Pine stands were divided into maturity
groups based on pine stands felling age for the commercial forests (forest group
IV) (Lietuvos miškų statistika, 2002). Four categories of stocking level were
distinguished: stands of low (≤0.5), medium (0.6-0.7), high (from 0.8 to 0.9) and
very high (≥1.0) stocking level. In this study, the area located up to 200 metres
from forest edge (perimeter) was considered as the core area. Open area, forage
area and forest glade were considered as the open area.
In order to determine the capercaillie lek selection, studies were carried
out in stages. The first stage aimed at identifying the variables of forest landscape
structure, which affect lek occupancy. The method of comparison of macrohabitats
with control landscapes was used (e.g. Bielański, 2006; Treinys, 2009). Since the
searching of leks was not performed in the control landscapes, these are named
throughout the study as “available landscapes” (Miettinen, 2009). First, all the leks
(n=71) (surrounding of 1 km radius around the centre) were compared with the
available landscapes (n=71), located at 2-5 km from the centre of leks. The 1 km
radius was chosen, because it contained the whole lekking area (Wegge and
Larsen, 1987; Storch, 1997). In addition, high occupancy leks (n=41) and low
occupancy leks (n=30) were separately compared with available landscapes. In
order to reveal the differences between high and low occupancy leks and
significant distances, leks were compared keeping a distance of 0.25, 0.5, 1 and 2
km from the centre. The longest radius (2 km) was chosen as a limitary, because
the strongest effect of landscape structure on the number of capercaillie males per
lek was found up to this radius (Miettinen et al., 2005).
The regional differences of leks surrounding and available landscapes were
evaluated in the second stage. A comparison of all the aforementioned variables of
forest landscape structure at 1 km in radius in Dzūkija leks (n = 29), Aukštaitija
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leks (n = 41) and in available landscapes located at 2-5, 5-10 and 10-20 km from
the lek centre was made.
Lek selection analysis. Stepwise discriminant analysis was used to select the
variables of forest landscape structure, influencing the selection of high and low
occupancy leks in two regions (for more details see next section).
2.1.3. Calculations and statistical analysis Geographic data were processed using standard functionality of ArcGIS
software. The areas of all the variables constituting forest structure were estimated
using statistical software package SAS 9.3. The primary analysis of all the
variables was made separately in each region by principal component analysis
using SAS/PRINCOMP procedure. Since the values of all variables were displayed
on the same scale, covariance analysis method was applied. The results of the
principal component analysis of both Aukštaitija and Dzūkija regions, which were
obtained by the Broken Stick method, showed that the first four components in
both regions were significant (explained variability from 4% to 56%). Having
selected the variables, those absolute weights exceeded 0.01 at the axes of principal
components, 24% of all variables were present in Aukštaitija region and only 5%
in Dzūkija. The average weight of selected variables in four axes was 0.08 and
0.26, respectively. In order to assess the multicolinearity of variables, the
correlation matrix between the variables, which was obtained during the principal
component analysis, was analysed. The values of correlation coefficients, which
were higher than 0.4, showed a close relationship between the variables. Pearson
correlation coefficients between the variables and correlation reliability were also
estimated. The obtained results were taken into account while interpreting the
influence of individual factors on lek selection. In order to evaluate the influence
on lek occupancy, data samples were compared with Kolmogorov-Smirnov
criterion (Zar, 2010), because data samples did not meet normal distribution in
most cases. SAS UNIVARIATE procedure was used to test the normality of the
data distributions. Stepwise discriminant analysis SAS STEPDISC as well as
variables of lower than 0.05 level of significance (alpha) were used in order to
evaluate the selection of leks. The features that best distinguish the selection of
leks, occupancy and regional groups were determined. Factor analysis using SAS
SCORE and SAS FACTOR procedures was applied in order to investigate the
influence of forest structure to the occupancy of leks, while graphic representation
was made using SAS G3D. Cluster grouping was made using SAS CLUSTER and
SAS TREE procedures. MANTEL test (software PAST, version 2.17c; Hammer et
al., 2001) with 10 000 permutations was made in order to find out the inter-
regional differences between the variables of lek surrounding. A linear correlation
was calculated between habitat similarity matrices for individual radius areas.
Distance matrix was obtained after the application of geographical similarity
criterion, while similarity was obtained according to landscape variables using
Euclidian distance similarity criterion. Principal component analysis using SAS
PRINCOMP procedure was used to analyse lek selection (with regard to the
distance from the centre), lek occupancy and regional differences. In order to
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reduce the probability of type I error, conclusions about the differences between
sample groups were made only in the cases when the level of significance of
differences was not higher than 0.01.
2.2. Investigation of home ranges and movement of capercaillies
Radio-tracking method was used to investigate the home range size and
movement of capercaillies (Wildlife…, 1998). Studies were performed during the
period from 2010 to 2013 in two areas: Labanoras forest (Lithuania, 55⁰12'N;
25⁰49'E) and in the Poozyorskaya forest (Belarus, 55⁰59'N; 28⁰33'E). Birds were
captured at the lekking sites in spring, using fishing nets. One female and seven
males were caught in total. All birds were equipped (marked) with radio collars
(necklace type, 22 g weight and 2.3 years battery lifetime). The tracking of birds
was made 3-5 times a month. Portable receiver Telonics TR-4 with a 3-element
Yaggi antenne were used. During the tracking, the marked bird was approached
directly, except for the cases when males were on display ground and female were
hatching eggs. In these cases, locations were determined by triangulation
(Beshkarev et al., 1995). When encountering the birds, their locations were
determined on spot by GPS Garmin device and the date and the time, as well as the
bird’s behaviour, data on the use of habitat and environmental data were recorded
in the location. Data were grouped by bird’s sex and the time having considering
the period of biological cycle of capercaillies (Risultati dell' attivita..., 2011).
The calculations of the home range size and movement were performed by
using RangesV software and based on the geographical coordinates in the locations
of each tracked bird. The 100% Minimum Convex Polygon (100% MCP) method
was used when studying the individual home ranges size (Mohr, 1947; Jennrich
and Turner, 1969; White and Garrott, 1990). The distances (m) from the place
where the bird was caught to the centre of the home range and to the furthest point
of the location, as well the range span were estimated, too (Risultati dell' attivita...,
2011).
2.3. Analysis of capercaillies microhabitats surrounding
Data collection. Since the probability to register a naturally living bird during
the fieldwork is low (ß < 1.0) (Lancia et al., 1994), the data on the location of
capercaillies (microhabitats), which was collected by several complementary
methods, was used for studies. The method of direct observation throughout a
year (Dzieciolowski and Matuszewski, 1980) was used for research. All observed
birds and their detected activity signs: traces, excrements under nocturnal trees,
dust baths, wing-traces on the snow, individual excrement, nests and chick broods
during the period from 2008 to 2012 were recorded. Using the data obtained by
radio telemetry method in Lithuania and Belarus during the period from 2010 to
2013. By questionnaire method: the questionnaire “Registration of capercaillies
in Lithuania” compiled in 2012 was uploaded to the website of the Institute of
Forestry, Lithuanian Research Centre for Agriculture and Forestry
(http://www.mi.lt/mi/images/pdf/anketa_kurtiniai.pdf, last accessed on
01/02/2012). Mainly foresters and the employees of the protected areas completed
the questionnaires about noticed capercaillies or the locations of their activity signs
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and submitted them during the period from 2012 to 2013. The locations indicated
in the questionnaires were checked during the fieldwork according to the GPS
coordinates.
The data of 526 locations of capercaillies obtained in Lithuania (Dzūkija and
Aukštaitija) and Belarus (the Poozyorskaya forest) during the studies (from 2008 to
2013) were used in further studies. Two hundred forty (240) locations of
capercaillies were detected by radio telemetry method (50 locations in Lithuania);
259 capercaillies and/or locations with activity signs were found by detection (197
were found in Lithuania and 62 in Belarus); and 27 locations of capercaillies were
found using a questionnaire method (all these locations were found in Lithuania).
Data analysis. In all detected capercaillie microhabitats the geographic
coordinates were recorded using the GPS device and the following forest structure
parameters within 50 meters around were described: tree species composition, age,
the stocking level, ground layer, ecotones and the objects of infrastructure. Stand
species composition and site humidity were assessed visually. Since stand species
composition in capercaillie locations was very diverse at different time of the year,
stands were grouped according to the aforementioned indicators by distinguishing
10 categories of biotopes (Balčiauskas et al., 2008). The names of the biotope were
given according to the dominate tree species in the stand. The data was processed
using EXEL MS software.
Comparative analysis was used in order to further examine stand structure in
the microhabitats of capercaillies and to compare the habitats used by birds of
different sexes. The information stored in the Belorussian forest inventory
databases was not available; therefore, only the microhabitats of capercaillies
detected in Lithuania were used in the study. First of all, the database of
geographical positions was created for all (n=274) microhabitats. One random
point was established for each microhabitat using ArcGIS random point generator.
The points were located in the buffer zone leaving a distance of 2-5 km from the
centre of microhabitats. Circular area 50 m in radius (790 m2) was established
around each point marking the microhabitat and around the random point. The
following variables were identified in these areas: 1) dominant tree species in the
stand; 2) forest type; 3) site type; 4) pine stands age; 5) stocking level; 6) second
stand layer. The same databases, which were used to investigate lek surrounding,
were used in this investigation as well. The calculations of the areas of all the
aforementioned variables of stand structure were made using the statistical
software package SAS 9.3. The characteristics of stand structure in the
microhabitats of capercaillies (males and females separately) and the
characteristics of stand structure in random points were described and compared. In
order to evaluate the differences of microhabitats used by males and females, they
were compared with each other (and in individual regions as well). The differences
were tested using the Kolmogorov-Smirnov criterion (Zar, 2010), because data
samples did not meet normal distribution in most cases (checked by
UNIVARIATE procedure).
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3. RESULTS AND DISCUSSION
3.1. Peculiarities of the capercaillies lek selection
In order to identify the peculiarities of the capercaillies lek selection, the
influence of individual variables of forest landscape structure on the occupancy of
leks and regional differences of forest structure were assessed first.
3.1.1. The influence of forest landscape structure variables to the
occupancy of capercaillie leks
Tree species composition. The proportion of pines in the stand in lek
surrounding and available landscapes was significantly different (Table 1). The
proportion of pine in available landscapes was significantly (p=0.004) lower if
compared with high occupancy leks, and did not differ significantly (p=0.17) if
compared with low occupancy leks. The proportion of pines in high occupancy
leks was significantly higher at the radii 0.25 km (p=0.029), 0.5 km (p=0.008) and
1 km (p=0.009) if compared with low occupancy leks.
The proportions of other four tree species (spruce, birch, black alder and aspen)
in lek surrounding and available landscapes were similar (Table 1). The proportion
of the aforementioned tree species in the stand did not differ significantly (p>0.05
in all the cases) in available landscapes if compared with both high and low
occupancy leks. Comparison of different occupancy leks revealed that the
proportion of all tree species was similar (p>0.05 in all the cases) regardless of the
analysed distance.
Table 1. Descriptive statistics of forests (the average ± SD, %) in capercaillie leks
surrounding (n=71) and available landscapes (n=71) at 1 km radius. Also the results of
statistical comparison of Kolmogorov-Smirnov (KS) test. Significant differences (p<0.05)
are in bold.
Variable Leks Available
landscapes KS test results
Tree species
composition
Pine 82.9 ± 11.2 70.9 ± 21.9 0.004
Spruce 6.5 ± 6.1 9.5 ± 6.5 0.054
Birch 8.6 ± 4.8 15.5 ± 9.4 0.084
Black alder 1.3 ± 2.0 3.2 ± 5.8 0.084
Aspen 0.1 ± 0.2 0.3 ± 0.7 0.26
Pine-stands
age
Clear-cuts 2.9 ± 2.8 4.1 ± 4.3 0.18
Young 9.4 ± 9.6 15.2 ± 9.6 0.12
Middle-aged 43.4 ± 15.2 33.4 ± 15.6 0.0012
Premature 23.1 ± 15.7 20.4 ± 14.3 0.185
Mature-overmature 21.2 ± 15.4 22.1 ± 16.0 0.99
Stands
stocking
level
Low (≤ 0.5) 4.8 ± 3.9 7.1 ± 5.1 0.084
Middle (0.6-0.7) 36.9 ± 16.4 36.9 ± 15.2 0.61
High (0.8-0.9) 55.2 ± 18.6 47.5 ± 16.6 0.0001
Very high (≥1.0) 3.1 ± 4.1 5.6 ± 7.5 0.034
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Forest type
Vaccinio-myrtillosa 59.2 ± 26.7 55.8 ± 51.9 0.061
Cladoniosa 10.3 ± 15.4 13.9 ± 21.7 0.011
Ledo-sphagnosa 8.0 ± 13.4 7.1 ± 10.1 0.601
Carico-sphagnosa 6.3 ± 7.8 5.7 ± 6.3 0.026
Myrtillosa 5.9 ± 4.8 5.6 ± 7.9 0.151
Oxalidosa 5.2 ± 7.6 6.7 ± 9.6 0.004
Vacciniosa 4.4 ± 3.6 4.5 ± 4.1 0.090
Pine stands age. Middle-aged pine stands in lek surrounding covered a
significantly greater proportion of the area if compared with the available
landscapes. Comparison of the proportions of other maturity groups, as well as the
clear cuts (Table 1) revealed no significant differences The proportion of middle-
aged pine stands in available landscapes was significantly lower if compared with
high occupancy leks (p=0.004), and did not differ significantly (p=0.24) if
compared with low occupancy leks. The proportion of clear cuts, young stands,
pre-mature, mature-overmature pine stands in available landscapes did not
significantly differ if compared with both high and low occupancy leks (p>0.05 in
all the cases). Proportions of pine maturity groups as well as the clear cuts did not
differ significantly (p>0.05 in all the cases) on the leks with different occupancy
level regardless of the radius.
Stands stocking level. The proportions of low (≤0.5) and medium (0.6-0.7)
stocking level stands were almost the same in the lek surrounding and in available
landscapes. Meanwhile, the proportions of high (0.8-0.9) stocking level stands
were significantly larger in leks; while the proportions of very high (≥1.0) stocking
level stands were significantly smaller (Table 1). The proportion of low stocking
level in available landscapes did not differ significantly (p>0.05) if compared with
both high and low occupancy leks. The proportions of medium and high stocking
level in available landscapes were significantly smaller if compared with both high
and low occupancy leks (p<0.05 in all the cases). The proportions of very high
stocking level in available landscapes were significantly larger if compared with
both high and low occupancy leks (p<0.05). Comparison of different occupancy
showed that the proportions of all stocking level stands were similar (p>0.05 in all
the cases) regardless of the analysed distance.
Forest type. The proportions of Vaccinio-myrtillosa, Ledo-sphagnosa,
Myrtillosa and Vacciniosa stands in lek surrounding and in available landscapes
were similar (Table 1). Meanwhile, the proportions of Carico-sphagnosa stands in
leks were significantly higher, and the proportions of Cladoniosa and Oxalidosa
stands were significantly lower if compared with available landscapes (Table 1).
The proportions of Vm, M, V and Csp stands in available landscapes did not
differ significantly (p>0.05) if compared with both high and low occupancy leks.
The proportions of Lsp stands in available landscapes were significantly lower
(p=0.007) if compared with high occupancy leks and were significantly higher
(p=0.0003) if compared with low occupancy leks. The proportions of Ox stands in
available landscapes were significantly higher (p=0.009) if compared with high
occupancy leks and did not differ significantly (p=0.09) if compared with low
14
occupancy leks. Meanwhile, the proportions of Cl stands did not differ
significantly (p=0.37) if compared with high occupancy leks and were significantly
lower (p=0.007) if compared with low occupancy leks.
While comparing leks of different occupancy, the proportions of all forest type
stands within radii 0.25 km and 0.5 km did not differ significantly (p>0.05 in all
the cases). However, significantly larger proportions of Lsp stands were typical in
the leks of high occupancy in radii of 1 and 2 km (p<0.04 and p=0.002,
respectively) if compared with low occupancy leks. Meanwhile, the proportions of
Cl, Vm and Ox stands were larger significantly (p<0.05 in all the cases) in low
occupancy leks.
Forest land covered on average 87.9 ± 2.5% (SD) and 76.9 ± 16.5% (SD) of
the area in lek surrounding and in available landscapes, respectively (significant
difference, p<0.0001). Forest land proportions in high and low occupancy leks
surrounding were significantly larger (p<0.0001) if compared with available
landscapes. Comparison of the three radii up to 1 km from the centre revealed that
high and low occupancy leks did not differ from each other (p>0.05 in all the
cases). However, forest land proportion in high occupancy leks at 2 km in radius
was approximately 5% larger (significant difference, p=0.006).
Stands covered a similar proportion in lek surrounding and in available
landscapes (on average 95.6 ± 4.4 (SD) % and 94.8 ± 3.8 (SD) %, respectively)
(insignificant difference, p>0.05). No significant differences (p>0.05) were found
when comparing available landscapes with both high and low occupancy leks. No
significant differences were established when comparing leks of different
occupancy (p>0.05 in all the cases), regardless of the radius.
Core areas covered on average 79.8 ± 19.2 (SD) and 60.4% ± 22.7% (SD) of
the analysed area (p<0.0001) in lek surrounding and in available landscapes,
respectively. Core area proportions in high and in low occupancy leks were
significantly larger (p<0.0001) if compared with available landscapes. Core area
proportion in high and low occupancy leks did not differ significantly (p>0.05 in
all the cases), regardless of the radius.
Distance to the nearest forest edge. Leks (when measured from the centre)
were located about 350 m further from the forest edge (the average distance was
1470.3 ± 721.5 (SD) m) than available landscapes (1120 ± 301.5 (SD) m)
(significant difference, p<0.0001). High and low occupancy leks were significantly
(p<0.0001 in both cases) further from the forest edge than available landscapes.
Comparison of different occupancy leks revealed that high occupancy leks were
located about 180 m further from the forest edge (insignificant difference, p>0.05).
Open areas covered on average 2.3 ± 1.2 (SD) % and 3.8 ± 8.9 (SD) % in lek
surrounding and in available landscapes, respectively (insignificant difference,
p=0.54). Comparison of available landscapes and both high and low occupancy
leks revealed no significant differences. In addition, different occupancy leks did
not differ significantly from each other (p>0.05 in all the cases), regardless of the
radius.
15
Drained wetlands covered on average 4.1 ± 5.1 (SD) % and 6.2 ± 8.9 (SD) %
of research area in lek surrounding and in available landscapes, respectively
(insignificant difference, p=0.36). No significant differences (p>0.05) were found
when comparing available landscapes with both high and low occupancy leks. In
addition, different occupancy leks did not differ significantly from each other
(p>0.05 in all the cases), regardless of the radius.
Wetlands covered on average 15.6 ± 22.2 (SD) % and 14.1 ± 18.1 (SD) %, in
lek surrounding and in available landscapes, respectively (insignificant difference,
p=0.36). No significant differences were found when comparing available
landscapes with both high and low occupancy leks (p>0.05). Meanwhile, the
comparison of different occupancy leks revealed that the areas of wetlands were
significantly larger by 2.5-3 times in high occupancy leks (p<0.05 in all the cases)
at all analysed radii (Fig.2).
Fig. 2. The proportion of wetlands in the available landscapes (n=71) and low
(n=30) and high (n=41) occupancy capercaillie leks depending on radius from center
The distance to the nearest road with pavement from leks and available
landscapes (when measured from the centre) was about 815.7 ± 604.1 (SD) m and
590.2 ± 494.2 (SD) m, respectively (insignificant difference, p=0.08). High
occupancy leks kept significantly (p<0.01) longer distance, while low occupancy
leks kept insignificantly (p>0.78) longer distance to the road with pavement if
compared with available landscapes. High occupancy leks maintained about 260 m
(insignificant difference, p=0.53) longer distance to the road with pavement
(approx. 690 m).
The density of roads with pavement was on average 452.9 ± 430.6 (SD)
m/km² and 682.8 ± 603.8 (SD) m/km² (p=0.054) in lek surrounding and available
landscapes, respectively. The density of roads with pavement in available
landscapes was significantly (p<0.05) higher if compared with high occupancy
leks, while the differences were insignificant (p>0.05) when comparing with low
occupancy leks. No significant differences were found when comparing different
occupancy leks (p>0.05 in all the cases), regardless of the radius, although the
16
density of roads with pavement at 0.25 km and 0.5 km in radii in high occupancy
leks was about 1.5-2 times lower.
The distance to the nearest forest road from the capercaillie leks and
available landscapes was on average 480.7 ± 778.8 (SD) m and 590.3 ± 1132.6
(SD) m, respectively (insignificance difference, p=0.36). Both high and low
occupancy leks kept insignificantly longer (p>0.05) distance to the forest road than
available landscapes. High occupancy leks were about 560 m further from the
forest road, while low occupancy leks kept a distance of about 640 m to the forest
road (insignificant difference, p>0.71).
The density of forest roads was on average 1640.4 ± 1034.7 m/km² and
1504.6 ± 961.0 (SD) m/km² in lek surrounding and available landscapes,
respectively (insignificant difference, p>0.48). No significant differences (p>0.05)
were found when comparing available landscapes with both high and low
occupancy leks. Comparison of different occupancy leks showed that the density of
forest roads did not differ significantly in them (p>0.05 in all the cases), regardless
of the radius.
The distance to the nearest homestead from the capercaillie leks and
available landscapes was on average 1850.3 ± 1080.9 m (SD) and 1248.4 ± 989.4
m (SD) (significant difference, p<0.0001). High occupancy leks kept significantly
(p<0.0001) longer distance to the nearest homestead, while low occupancy leks
kept insignificantly (p=0.218) longer distance to the nearest homestead if
compared with available landscapes. Study revealed that high occupancy leks were
located much further from a homestead (significant difference, p=0.04) (approx.
2040 m) than low occupancy leks (approx. 1450 m).
3.1.2. Regional differences
Complex comparison (Table 2) showed that lek surrounding of different
regions differed in about one-third of all the analysed elements. The highest
number of differences between the regions was found in available landscapes,
located 2-5 km from the leks. The number of significant differences in the
variables of forest structure in available landscapes located 5-10 km from leks (if
compared with the differences in leks) decreased more than twice. No differences
were found in available landscapes located 10-20 km from leks. Mantel test results
revealed a declining correlation between the geographic distance and all the
analysed variables receding from lek centre. The obtained correlation results were
significant for leks (R=0.36) and for available landscapes located 2-5 km from leks
(R=0.22) (Fig. 3 A, B). The correlation was not significant for available landscapes
located 5-10 km and 10-20 km (R=0.09 and -0.06, respectively) from leks (Fig. 3
C, D).
Table 2. Results of comparison of forest landscape structure at 1 km in radius in
Dzūkija leks (n = 29), Aukštaitija leks (n = 41) and in available landscapes located at 2-5, 5-
10 and 10-20 km from the lek centre. The number of available landscapes is equal to the
number of leks. Kolmogorov-Smirnov (KS) test was used. The significance level: *–
17
0.05>p>0,01, ** – 0.001>p<0.01, ***– <0.001. Empty cells mean that the differences were
not significant.
Variable
Leks
Available
landscapes
2-5 km
Available
landscapes
5-10 km
Available
landscapes
10-20 km
Forest land
Core area
Stands
Wetlands
Drained wetlands * *
Open areas
Roads with pavement ** **
Forest roads ** ***
Distance to:
Forest edge
Road with pavement *
Forest road * **
Homestead * *** *
Pine-dominated stands age:
Clear-cuts
Young ** **
Middle-aged ***
Premature * *
Mature-overmature *
Proportion of tree species
Pine * *
Spruce *** ** *
Birch * *
Black alder
Aspen
Proportion of stocking level
≤0.5 *
0.6-0.7
0.8-0.9
≥1.0
Proportion of forest type
Vaccinio-myrtillosa ** *
Cladoniosa * *
Oxalidosa ** ***
Vacciniosa *
Myrtillosa
Ledo-sphagnosa
Carico-sphagnosa
Regions mostly differed in the following variables: density of the roads with
pavement, density of forest roads, proportion of drained wetlands, distance to a
18
homestead and distance to forest road, proportion of middle-aged pine, spruce
stands, Vm and Ox forest type sites. The average canonical correlation coefficient
of all these variables was R=0.40.
A B
C D Fig. 3. Mantels test’s analysis of forest structure variables at 1 km radius in: leks
surrounding (A); available landscapes at 2-5 km distance from leks (B); available landscapes
at 5-10 km distance from leks (C); available landscapes at 5-10 km distance from leks (D)
3.1.3. The influence of forest structure on the capercaillie lek selection
The comparison of leks at 0.25, 0.5, 1 and 2 km in radius revealed that lek
environment differed up to 0.5 and from 0.5 km in radius most. Meanwhile, the
surrounding remained almost the same in the restricted areas at 0.25 km from 0.5
km and 1 from 2 km in radius. The analysis of the capercaillies preferred leks in
different regions within a distance of 0.5 km from the centre in high and low
occupancy leks revealed the influence of variables of the same forest landscape
structure. In addition, the influence of the same variables was also typical on the
selection of leks in different regions (Dzūkija and Aukštaitija). These variables
included: low (0.5), medium (0.6-0.7) and high (0.8-0.9) stocking level stands, pine
stands, middle-aged pine stands, mature-overmature pine stands, wetlands, stands
of Vm and Lsp forest type and core area (Fig. 4).
19
A B
C D Fig. 4. Forest landscape variables, influencing the capercaillie leks selection at 500 m radius
in Dzūkija (high-A; low-B occupancy leks) and Aukštaitija (high-C; low-D occupancy leks)
Meanings: stands (me); forest land (mi); wetlands (pe); drained wetlands (nu); open areas (ai); core area (mv); roads with pavement (kd); forest roads (mk); distance to the forest edge (mp); distance
to the road with pavement (ad); distance to the forest road (am); distance to the homestead (as); pine
stands (P); clear cuts (ki); young pine stands (P_jaun); middle- aged pine stands (P_pus), premature pine stands (P_prib); mature-overmature pine stands (P_br); spruce stands (E), young spruce stands
(E_jaun); middle-aged spruce stands (E_pus), old spruce stands (E_sen); birch stands (B); young birch
stands (B_jaun); middle- aged birch stands (B_pus), old birch stands (B_sen); cl, ox, lsp, csp, v, vm, m – stands of different forest types; _05, 0.6-0.7, 08-0.9, _10 – stands of different stocking level
Discussion. The influence of forest landscape structure on the occupancy of
leks of capercaillies. The lek surrounding differed from available landscapes in
about one third of all the analysed variables of forest landscape structure. The
obtained results confirm one of the defended statements, because more
(statistically significant) differences were found while comparing available
landscapes with high occupancy leks than comparing with low occupancy leks of
capercaillies. This shows the influence of specific variables to the occupancy level
20
of leks. The surrounding of low and high occupancy leks located at different
distance from the centre differed in the following variables: stand species
composition, forest type, areas of forest land and wetlands, and distance to forest
edge, to a homestead, to the roads with pavement and their density. Different
occupancy leks did not differ in the following variables: proportion of the clear
cuts and pine stand age, stocking level of the stands, proportion of the stands, core
areas, open areas, drained wetlands, density of the forest roads and distance to
them.
The proportion of forest land and forest depth in leks was significantly higher if
compared with the landscape around random points. This fact showed that leks
were spread throughout relatively less fragmented forest areas. This is in full
agreement with the opinion of other researchers who claim that leks are located in
continuous forest tracts (Rolstad and Wegge, 1987; Helle et al., 1994). Smaller
forest land proportion was found in low occupancy leks at 2 km in radius, while the
distance from low occupancy leks to forest edge was shorter. Stands proportion, in
contrast to the proportion of forest land, was smaller in high occupancy leks if
compared with low occupancy leks. This shows that a greater forest fragmentation
was typical to low occupancy leks than to high occupancy leks. Forest
fragmentation is considered to be one of the main factors negatively affecting the
abundance of capercaillie populations worldwide (Andrén, 1994). However, in
order to clarify the obtained results, research should be continued further.
The proportions of wetlands and stands of Ledo-sphagnosa forest type had a
tendency to be larger in high occupancy leks than in low occupancy leks at all
analysed radii. On the contrary, proportions of Vaccinio-myrtillosa, Myrtillosa,
Vacciniosa, Oxalidosa and other forest type stands were larger in low occupancy
leks. That shows a positive influence of wetlands on the occupancy of leks. Results
revealed that low occupancy leks were located closer to homesteads, roads with
pavement and the density of roads with pavement was higher there. This suggests
that anthropogenic disturbance sources are one of the most significant factors to
determine lek occupancy level. The obtained results are in full agreement with the
results of other authors, who indicate that the anthropogenic factors affect the
capercaillies’ choise of habitats (Leclercq, 1985; Ménoni and Bougerol, 1993;
Sachot et al., 2003).
Lek selection. Regardless of forest structure differences of two regions in the
surrounding of capercaillie leks and in the area up to 5 km in radius from leks, lek
selection was influenced by the same variables, which are as follows: stands of low
(≤0.5), medium (0.6-0.7) and high stocking level (0.8-0.9), pine stands proportion,
middle-aged, mature-overmature pine stands, wetlands, Vaccinio-myrtillosa and
Ledo-sphagnosa forest types and core area. The influence of the aforementioned
variables on lek selection was obvious at 0.5 km in radius from the centre of leks.
This shows lek uniqueness in the central part, which have the so-called male
display grounds. The influence of forest structure on lek selection was not revealed
within the distance of 1 and 2 km from the centre of leks, because these areas were
under the boundaries of daily territories of males. The surrounding of these areas
21
was less distinct if compared with display grounds. In addition, the same variables
were typical to both high and low occupancy leks. This tendency shows that the
differences of lek surrounding (or, in other words, habitat quality) can explain the
occupancy of leks.
Capercaillies prefer pine stands throughout their range (Logminas, 1962;
Seiskari, 1982; Черкас, 2008). The results of this analysis revealed that lek
selection was influenced by middle-aged and mature-overmature pine stands (when
considering stand age). The prior studies emphasized the importance of old forests
(e.g. Hjorth, 1970; Wegge and Rolstad 1986; Picozzi et al., 1992; Kurki et al.,
2000). There is no uniform opinion about the influence of pine stands of different
maturity groups on the lek selection of leks. It is said that mature stands, which
grow in the intensive management forests, lose some characteristics typical to
natural forests (Miettinen et al., 2009). In order to adapt to the changing conditions
(Dzieciolowski and Matuszhewski, 1980), capercaillies are forced to choose
younger forests (Mykrä et al., 2000; Miettinen et al., 2005; Sirkiä et al., 2011). The
results of this study as well as the results obtained by Sirkiä et al. (2011) in Finland
(leks were analysed at 3000 m in radius) show that lek occupancy did not depend
on the share of old stands. According to the data of the studies carried out by
Miettinen (2009), even the areas of young pine stands in managed forests in
Finland positively correlated with the males’ number at the lek.
It is likely that stands of high (0.8-0.9) stocking level had a negative influence,
because dense stands reduce the chances of capercaillies to escape from predators
(Rolstad and Wegge, 1990). In this paper, the stands of low (≤0.5) and high (0.6-
0.7) stocking level were identified as factors influencing lek selection. Other
authors also mentioned the preference of capercaillies in the thin stands. I. Storch
(1993) argued that approx. 2/3 of middle-aged stands in central Europe are too
dense for capercaillies, especially multi-storey stands (stands with more than one
storey). It is said that capercaillies use open areas for mating where visibility is 20-
50 m (Valkeajärvi and Ijäs, 1986; Miettinen, 2009). When collecting data, the
mating games of capercaillies were often detected on the forest roads, compartment
and electrical lines. These findings agree with the findings of other authors
(Dzieciolowski and Matuszewski, 1980).
The results of this study indicated that wetland areas (Ledo-sphagnosa forest
type), influenced lek selection and lek occupancy. Meanwhile, Vaccinio-myrtillosa
forest type stands were very important for after mating period.
22
3.2. The home range size of capercaillies
Eight radio-tagged capercaillies (7 males and 1 female) were tracked during the
study period. Two hundred eighty (280) locations of these birds were registered in
total. The size of the total annual home ranges used by individual birds and home
ranges used at different time of the year were defined based on the obtained data
(Table 3).
Spring. Birds were captured and radio-tagged at the end of their mating period
(the second half of April). The home range used by the male M303 amounted to
32.3 ha from April 23 to May 10, 2010. The bird moved 1.1 km the farthest from
the place of its capture. The area used by this bird in next year’s spring, from 1
April until mid-May, amounted to 51.2 ha, while 1.3 km was the maximum
distance from the lek (the place of capture). During the same period, the area used
by another male (M02) was slightly larger (63.8 ha) and the maximum distance
from the lek was 1.5 km (Table 3).
Table 3. The home range (HR) and movement distances of radio-tracked capercaillies (n=8)
Ind
ivid
ual
Nu
mb
er
of
loca
tio
ns
Ho
me
ran
ge
size
, h
a
Max
.
dis
t.fr
om
lek
/nes
t, m
Ran
ge
span
,
m
Dis
tan
ce
fro
m l
ek t
o
the
HR
cen
tre
No
tes
Spring (before mating period) M303 (2011) 14 1419.0 6471 5120 4166
Spring (mating period)
M303 (2010) 7 32.3 1087 1081 480
M303 (2011) 17 51.2 1250 1501 869
M217 3 - - - -
M336 2 - - - -
M286 2 - - - -
M263 1 - - - -
F01 0 - - - -
M01 5 26.6 850 1167 621 †2011.05.05
M02 16 63.8 1474 1462 781
Av. M303, M02 13 49.1 1271 1353 710
Summer – autumn F01* 25 427.3 1908 2713 1057 †2011.07.12
M303 (2010) 28 395.1 7647 2765 5923
M303 (2011) 16 443.6 5785 3969 4615 †2011.11.20
M217 14 206.5 2610 2633 995
M336 10 1278.6 7714 6916 5833
M286 12 90.9 1296 1296 615 L2011.06.06
M263 19 149.4 2799 2615 1384
M02 21 153.8 2850 1952 1723
23
Av. males ** 17 388.3 4385 3164 3013
Winter M303 (2010) 13 315.3 4125 1125 4046
M02 8 61.0 2696 1937 1407 †2013.02.25
Av. M303, M02 11 188.0 3411 1531 2727
Annual Period M303 (2010) 65 2810.9 7631 7877 4545 04.23-11.30
M303 (2011) 76 1999.2 7805 6733 4210 12.01-11.30
M217 17 206.5 2610 2633 995 05.16-11.30
M336 13 1278.6 7714 7714 5181 05.16-11.30
M286 14 90.9 1296 1296 615 04.04-06.06
M263 20 149.4 2799 2615 1383 05.16-11.30
F01* 25 427.3 - 2713 1057 05.03-07.12
M01 5 26.6 850 1167 621 04.28-05.05
M02 45 384.7 2850 2602 1435 04.18-02.25
Av. males*** 32 988.6 4672 4495 1932
Note: The number of locations of two capercaillies (males M303 and LT02) during these
studies was sufficient to statistically reliably estimate the size of home ranges. *- the data of
the female F01 after it has left the nest (05.03). **- the data of the males M336 and M286
are not included. ***- the data of the male M01 are not included. Symbol „†“ means that
individual died; „L“- individual lost radio-collar. Av means average
The pre-mating period in spring was distinguished in March when the
capercaillie M303 lived in relatively large area (1419.0 ha) (Fig. 5, Area No. 3).
This male bird was detected even 6.5 km from the lek. From March 1 to April 6
2011 this male bird visited three other leks and was located in the lek on April 7
where it was captured in 2010.
Fig. 5. The spatial distribution of home ranges of the male M303 by separate months
24
Summer-autumn. After the end of the mating period, the male M02 was
detected in 43.3 and 110.5 ha areas in summer and autumn, respectively, while the
longest distance the bird moved from the lek was 1.6 km and 2.9 km, respectively.
The male M303 was detected within its lek area in two consecutive years (2010
and 2011) during the first days of May. In the middle of May 2010, the bird was
detected at the distance of 6.3 km from the lek, and at the distance of 5.7 km from
the lek during the same period of 2011 (Fig. 5, Area No. 5-7). The male M336 was
detected at larger and larger distances from the lek during May-June. This bird was
registered at the longest distance (7.7 km) from the lek in autumn (it was migrating
towards Russia). The signal of this bird was unreachable in winter. It means that
the bird migrated in relatively long distance (more than 5 km). In spring 2012
(March), the bird returned to the lek where it was first captured. Meanwhile, the
area of the female F01 amounted to 427.3 ha during three months period (May-
June-July), while the range span as a distance between the two farthest locations
was 2.7 km.
It should be noted that the number of observed locations of capercaillies was
different in summer and autumn (Table 3); therefore, the data obtained during
these periods are discussed commonly. During summer-autumn period, home
ranges of males (excluding M286 and M336) were on average 270 ha and ranged
from the minimum area of 149 ha (M263) to the maximum area of 444 ha (M303,
2011). The home ranges (when measured from the centre) were also distributed
from leks at different distance, which ranged from 1.3 km (M286) to 7.7 km
(M336), (the average 4.5 ± 4.5 (SD) km). The biggest part of the home range of the
male M336 was beyond the large homogeneous sphagnum-dominated bog with
rare pines where the bird was detected in the first half of summer (Fig. 6).
Fig. 6. The distribution and home range size of the capercaillie males (n=5) in the period
from May 16 to November 30, 2011
25
Winter. Home ranges of the male M303 covered 22.9 ha during the period
from December to January. Four kilometres was the farthest distance from the lek
(the place of capture). The activeness of this bird increased in February and its
home range amounted to 305 ha. Meanwhile, the area of the male bird M02
amounted to 61 ha during the period from December to February, while the
distance from the lek to the centre of home range stood at 1.4 km (Table 3).
Annual home ranges. During the period from April to November, home
ranges of observed male birds M303 (2010 and 2011), M336, M217 and M263
covered on average 1289 ± 1150 (SD) ha and ranged from 149 to 2811 ha. The
distance from the lek (when measured to the centre of the home range) was on
average 3.3 ± 2.1 (SD) km and ranged from 1.0 km to 4.5 m (Table 3).
After the mating period (mid-May through late November), home ranges of
only two males (M286 and M217) of five captured in one lek overlapped, but very
slightly (0.8-1.5%).
The data obtained while observing the male M303 allowed establishing the
links between this bird living periods and the dynamics of home ranges. According
to the moving activity of this male, the observed biological events, the feeding
character and the size of home ranges (calculated by 100% MCP method), 9
periods of biological cycle were distinguished in one calendar year.
Discussion. The number of locations of two tracked capercaillies (males M303
and LT02) during this study was sufficient to statistically reliably estimate the size
of home ranges. The size of home ranges of male capercaillies and the distance
from the lek were related to the season and varied among individuals. During the
mating period, males in daily territories kept the farthest distance of approx. 1.3 km
from the lek, while the average size of home ranges was 49 ha. According to the
results obtained in the Italian Alps, the average (maximum) distance from the lek
was analogous (approx. 1308 m), while the size of the ranges slightly differed
(covered approx. 64 ha) (Risultati dell‘attivita..., 2011). The mountainous terrain
features probably can explain larger home ranges in the Alps, because the height
above the sea level also influences the selection of habitats by capercaillies
(Risultati dell‘attivita..., 2011). After the end of the mating period, capercaillie
males lived keeping a difference distance to the lek (four males lived keeping a
distance of approx. 4.7 km, while two males migrated keeping a distance of
approx. 7.7 km). Other authors also documented seasonal migration of individual
males. According to Storch (1995), home ranges of males were 7.5 km and at
longer distance away from leks in summer and autumn. The results of the studies
carried out in Finland, Norway and Russia showed that individual males after
mating period migrated to summer habitats keeping a distance of 5 km, while the
majority of birds lived keeping a distance of 2.2-2.3 km from leks (Helle et al.,
1990; Hjeljord et al., 2000). The reasons of this phenomenon are not yet fully
analysed. The authors argue that males return to their home ranges by natural
dispersion ways. Other authors claim that seasonal migration is encouraged and
26
migration distances are determined by fragmented landscape and the lack of one of
the variables of seasonal habitats (Rolstad and Wegge, 1989).
Studies revealed that home ranges of capercaillies were the smallest in winter
and ranged from 61 to 315 ha. These figures were found to be very close to the
sizes of capercaillie home ranges in the Alps (ranged from 18 to 50 ha) (Risultati
dell‘attivita..., 2011). The differences between the sizes of home ranges of
individual males are related to the age of these individuals (Storch, 1993). Young
males, which are “exploring” the environment, use larger areas (Gjerde and
Wegge, 1989). Old males, on the contrary, tend to live closer to the lek and are
much more territorial. Their home ranges overlap relatively much less than the
ranges of males of younger age groups (Storch, 1993). It is argued that territoriality
is also typical in daily territories during the mating period (Hjorth, 1982; Wegge
and Larsen, 1987). According to the results obtained in this study, annual home
ranges used by five males did not overlap even after the mating period (in summer
through autumn). However, these results can be hardly attributed to territoriality,
because another two and three non-marked males were detected at the end of the
summer in the same tree with the marked male M303 eating aspen leaves.
The obtained results about the return of males to the area of the same lek were
in agreement with the data of other researchers (e.g. Wegge and Larsen, 1987).
These authors, as well as Hjorth (1982), state that several leks are visited in spring
by yearlings and two-year old males. However, during this study, the male M303
visited three other detected leks from March 1 to April 6, 2011. In addition, on
April 7, the same male was observed in the lek (approx. 6 km away from the lek)
where it was captured in 2010. According to the results of this study, the male
M303 was attributed to the group of mature birds based on the external features.
Home range of female amounted to 427 ha. This range is about two times larger
than established by Helle and Kumpu (2002) in northern Finland, where the ranges
of females, which have also lost their broods, amounted to approx. 210 ha in
summer. The smallest home ranges of females are the smallest during the year in
winter and summer when they have no chicks. Annual home ranges amount to
approx. 840 ha (Helle and Kumpu, 2002).
3.3. Forest structure characteristics in capercaillie microhabitats
3.3.1. Biotopical distribution and the use of seasonal habitats The majority of all capercaillie microhabitats were detected in pure pine stands
and mixed pine-spruce stands, on dry and marshy sites (Table 4). This pattern
confirms the preference of capercaillies to pine stands.
In spring the capercaillies of both sexes were generally detected in the
microhabitats for mating, staying overnight in a tree, resting and feeding on
ground, and dust bathing (females only). The majority (70%) of all mating males
both and nocturnal trees (microhabitats) were detected in dry pine stands (59% of
them were pure pine stands and 11% were mixed pine-spruce/deciduous stands).
The remaining 30% of these microhabitats were registered in marshy pine stands
27
(27% of them were pure pine stands and 3% were mixed pine-spruce/deciduous
stands). The majority of male microhabitats for resting on the ground were
detected in dry pine stands (93%), and only 3 % in marshy stands. Approximately
2/3 of the microhabitats for resting on the ground were detected in pine and mixed
pine-spruce/deciduous stands. The majority (84%) of dust baths were also found in
dry pine stands (38% of them were found in pure pine stands and 52 % were
detected in mixed pine-spruce/deciduous stands). All dust baths were found on
forest roads and forest section lines.
The results of the studies on the microhabitats of male capercaillies, which
were observed only by radio telemetry method, also confirm the importance of
pine stands in spring: 40% and 21% of all the microhabitats were found in dry and
marshy pure pine stands, respectively. The majority of microhabitats in Belarus of
radio-tracked birds (in spring) were detected in premature and mature stands
(Table 5). Meanwhile, the displaying and nocturnal trees of the male M02 marked
in Lithuania were detected in pure 45-year old pine stand. During the mating
period, the microhabitats of feeding on the ground of radio-tagged males in Belarus
were detected in the biotopes of upland moors and marshy places where these birds
were observed eating cranberries.
28
Table 4. Kinds of activity in various biotopes of capercaillie males (M, number of
microhabitats n=452) and females (F, n=74)
Biotopes and their characteristics: PGS – pure pine stands, dry; PGP – pure pine stands,
marshy; PES – mixed pine-spruce/deciduous stands, dry; PEP – mixed pine-
spruce/deciduous stands, marshy; ELS – mixed spruce-deciduous stands, dry; ELP – mixed
spruce-deciduous stands marshy; LES – mixed deciduous with spruce stands, dry; LEP –
mixed deciduous with spruce stands, marshy; A – uplands; Ž – moors.
Kind of activity (microhabitat type)
Biotope
Sex
Dis
pla
yin
g
Sle
epin
g o
n t
ree
Fee
din
g o
n g
roun
d
Du
stin
g
Nes
tin
g
Bro
odin
g
Res
tin
g
Flu
shed
-lac
k o
f
info
rmat
ion
To
tal
PGS M 49 34 52 - - - 10 12 157
F 5 6 12 8 4 1 1 - 37
PGP M 26 11 19 - - - 2 3 61
F 2 - - - 1 2 - - 5
PES M 25 33 32 2 - - 18 15 131
F - 4 7 13 1 1 - 2 27
PEP M 8 15 11 - - - 2 - 36
F - - - - - - - - 0
ELS M - 3 4 - - - 3 2 12
F - - - 1 - - - - 1
ELP M - 6 3 - - - - - 9
F - - - 3 - - - - 3
LES M - - 2 - - - 1 1 4
F - - 1 - - - - - 1
LEP M - 2 1 - - - 4 - 7
F - - - - - - - - 0
A M - 7 25 - - - - 3 35
F - - - - - - - 0 0
Ž M - - 6 - - - - - 6
F - - - - - - - - -
29
Table 5. Frequency of radio-tagged capercaillie males (n=5) in various biotopes/stages of
forest stand growth according to the seasons of the year in Belarus. The total number of
locations n=235. Marking is the same as in Table 4.
The nocturnal trees of males in the leks near wetlands were generally (66%)
detected in dry micro-raised places and slopes, i.e. in forest-wetland ecotone.
Meanwhile, 34% of these microhabitats were detected in trees growing straight in
the wetland. Many microhabitats for staying overnight in a tree in the leks without
wetlands were detected near forest section lines (38%) and forest roads (30%). In
other cases, the trees for staying overnight grew in small, thin forest areas (17%)
and in the ecotone of stands of different maturity groups (15%). The nocturnal
trees of the male M02 tracked in Lithuania were detected for the several times in
the stand ecotone adjacent to the stand, where the first case of simplified
occasional cutting (Labanauskas) was made.
Biotope and
forest stand growth
Spring
01.III-15.V
Summer
16.V-31.VIII
Autumn
01.VIII-31.XI
Winter
01.XII-28.II
n % n
% n % n
%
PGS
Young and middle-
aged 4 16 3 13 2 29 1 8
Premature and
mature 21 84 21 87 5 71 12 92
Sum 25 40 24 32 7 10 13 43
PGP
Young and middle-
aged 3 23 0 0 0 0 4 67
Premature and
mature 10 77 9 100 7 100 2 33
Sum 13 21 9 12 7 10 6 20
PES,
PEP
Young and middle-
aged 0 0 0 0 0 0 3 33
Premature and
mature 9 100 7 100 16 100 6 67
Sum 9 15 7 9 16 24 9 30
ELS,
ELP
Young and middle-
aged 1 13 7 30 5 22 1 100
Premature and
mature 7 87 16 70 18 78 0 0
Sum 8 13 23 31 23 34 1 3
LES,
LEP
Young and middle-
aged 0 0 5 7 5 7 1 3
A, Ž 7 11 7 9 10 15 0 0
In total 62 100 75 100 68 100 30 100
30
The microhabitats of capercaillies were found in diverse biotopes in summer
(from mid-May through August) if compared with those in spring. The
microhabitats of radio-tagged males after mating season were detected in mixed
pine-spruce and mixed pine-spruce/deciduous stands: 31% and 7% of all summer
microhabitats were found in mixed pine-spruce and mixed pine-spruce/deciduous
stands, respectively (Table 5). The microhabitats of males for self-feeding in the
middle of the summer (July – August) were detected in pure pine stands and mixed
pine-spruce/deciduous stands in dry biotopes (in premature and mature stands).
Microhabitats of nesting and broods were mostly (70%) found in dry pine stands
(wood cutting areas and mature stands) and 30% were detected in marshy pine
stands (Table 4).
In autumn radio-tagged males in Belarus were often detected in mixed stands
with aspen in the upper storey, where the birds were eating aspen leaves. In
September, the locations of these birds were detected in mixed spruce-soft
deciduous (34%) and mixed pine-soft deciduous stands (24%). Several times a
group of males gathered in aspen stands at once (even in the same tree). In autumn,
the male M02 marked in Lithuania was detected in dry pine stands (mainly pure
pine stands) (91%). The remaining part (9%) of the bird’s locations was detected in
humid pure and mixed stands. This bird was never detected in mixed pine-aspen
stands.
In winter capercaillies were detected in pine stands (99% of the total number
of microhabitats during this season). Forty-two percent and twenty percent of
microhabitats were found in dry pure pine stands and marshy stands, respectively.
Thirty-eight percent of microhabitats were detected in dry and marshy mixed pine-
spruce and/or birch stands.
3.3.2. Forest structure characteristics in the surrounding of capercaillie
microhabitats No significant differences with regard to stand structure were found in Dzūkija
region when comparing capercaillie microhabitats with random points in two
Lithuanian regions (Table 6). This shows that capercaillies found a sufficient
number of habitats of necessary stand structure in Dzūkija. Meanwhile, the
environment of capercaillie microhabitats and the environment of random points
differed in many variables in Aukštaitija. This shows that stand structure obviously
limited the selection of habitats.
Statistically significant differences between male and female microhabitats
were found only in Aukštaitija region. The proportions of middle-aged stands in
female microhabitats were significantly (p=0.029) larger, while the proportions of
mature-overmature stands were significantly (p=0.044) smaller if compared with
those used by males.
31
Table 6. Characteristics of capercaillie microhabitats (CM), random points (RP) and the
results of their comparative analysis. The average proportion is given in %. The total
number of microhabitats used by males (M) in Dzūkija and Aukštaitija regions was n=80
and n=139, respectively; and the total number of microhabitats used by females (F), n=24
and n=32, respectively. The number of random points was equal to the number of
microhabitats. The significant differences (p<0.05) are highlighted
Dzūkija Aukštaitija
Variable
Sex
CM
RP
KS
test
results
CM
RP
KS
test
results
Dominant
tree specie
Pine M
F
99.8
97.4
32.3
94.0
0.35
0.99
99.4
100.0
80.4
76.1
<0.0001
0.011
Spruce M
F
0.0
0.0
2.0
0.1
0.93
1.0
0.2
0.0
9.4
11.6
0.020
0.28
Birch M
F
0.2
2.7
4.3
0.0
0.98
0.99
0.3
0.0
9.5
10.1
0.019
0.44
Forest
type
Cl M
F
29.8
37.0
24.0
33.3
0.89
0.99
7.9
12.9
10.9
9.9
0.86
0.99
M M
F
0.0
0.2
5.9
2.5
0,99
1.0
0.2
0.0
4.3
5.4
0.93
1.0
Msp M
F
0.6
0.4
0.0
0.0
1.0
0.99
2.4
0.0
0.0
0.0
0.58
1.0
V M
F
3.4
7.1
2.8
0.0
1.0
0.71
9.7
21.0
8.4
4.1
0,12
0.035
Vm M F
66.2 55.3
62.5 59.6
0.81 0.91
79.9 65.9
66.3 68.2
0.003
0.28
Site type
N M F
98.8 98.9
91.5 95.5
0.93 1.0
95.7 99.4
80.5 79.5
0.021 0.049
P M
F
0.6
0.7
3.7
0.0
1.0
0.99
1.9
0.6
12.9
11.2
0.59
0.28
L M
F
0.6
0.3
0.0
0.0
1.0
1.0
2.7
0.0
0.0
0.0
0.48
1.0
Stands
stocking
level
<0.5 M
F
1.8
0.9
4.9
1.8
0.94
1.0
4.3
1.9
3.9
3.4
0.99
1.0
0.6-0.7 M F
32.1 22.3
31.6 34.8
0.94 0.51
38.1 29.4
52.1 39.9
0.009
0.67
0.8-0.9 M
F
62.5
72.4
53.7
57.7
0.15
0.31
55.1
63.5
39.6
46.4
0.005
0.32
1.0> M
F
3.6
4.4
9.8
5.8
0.93
1.0
2.5
5.1
4.4
10.3
0.99
0.99
Stands with second layer
M F
0.0 0.0
5.9 0.0
0.35 1.0
3.7 2.2
21.1 17.9
<0.0001
0.28
Age of
pine
stands
Clear cuts M
F
1.2
0.0
3.5
5.3
1.0
1.0
1.0
5.8
4.8
3.9
0.97
0.99
Young M
F
5.3
9.1
8.9
1.4
0.72
0.93
1.5
3.1
9.7
8.6
0.09
0.99
Middle-aged M F
64.3 72.6
8.8 47.3
0.29 0.14
45.9 67.3
39.4 32.8
0.37
0.003
Premature M
F
19.6
12.7
17.8
25.7
0.79
0.18
24.8
12.6
18.2
26.7
0.51
0.30
32
Mature-
overmature
M
F
9.7
5.5
15.8
20.3
0.36
0.27
26.7
11.3
27.9
28.1
0.98
0.31
Discussion. Seasonal differences of capercaillie habitats with regard to the
period of life were identified in this study. Capercaillies were detected in pure pine
and mixed pine-spruce stands in winter and spring. During the cold season, the use
of coniferous stands was related to the diet: during that period, pine needles were
the main food (Ekedahl, 2005) inspite of low nutritional value (Lindén, 1984;
Gjerde, 1991). Capercaillies ate spruce needles in the forests, which had no pines
(Ekedahl, 2005). Infraspecific social relations also affected the distribution of birds
in late winter (Gjerde and Wegge, 1989; Saniga, 2003).
The age of pine stands used in spring by radio-tagged male capercaillies
differed: the displaying microhabitats and nocturnal trees used by premature males
monitored in Lithuania (in the Labanoras forest) were detected in a 45-year old
pure pine forest. It should be noted that the lek was earlier unknown in this place,
while mating games of 5-6 males were observed in this lek during the study period.
Results obtained in southern Finland indicate that old pine stands were used by
adult males, while subadult males and females preferred middle-aged stands
(Gjerde and Wegge, 1989). It is said that new leks were usually established by
young males (Gjerde et. al., 2000).
At the end of the mating period, capercaillies change feathers and loose the
flying possibilities; therefore, they need denser sites (Гаврин, 1969; Черкас,
2008). This could have influenced the migration of radio-tagged males in early
summer in Belarus towards mixed coniferous (spruce-pine stands) and coniferous-
deciduous stands. The use of pine stands in early summer was also related to
feeding conditions: all birds were often detected eating blueberries and cranberries.
In late summer and autumn (until frost), radio-tagged males in Belarus were
often detected in mixed spruce-soft deciduous, birch-aspen stands. However, this
was not typical to the male marked in Lithuania, because aspen was absent in the
habitats of this particular male. Such a difference in habitats could have been
influenced by the share this tree species covers in stands: aspen trees cover 9% of
the stand areas in northern Belarus (Проект организации и ведения..., 2006),
whereas in Lithuania less than 1% of the stands of the considered territories. On
the other hand, Rolstad (1988) also found that some males in the southeastern part
of Norway in summer chose aspen for feeding, while other males ignored aspen
completely. The author argues that due to intensive farming in forests, the share of
these trees in stands is reduced to the level, when aspen can become an
inaccessible source of food for capercaillies.
The results obtained on the seasonal distribution of capercaillie habitat were
difficult to compare with the data of other authors due to some methodological
and/or other differences in habitat description. Saniga (2003) also speaks about
seasonal differences in habitats used by capercaillies in the Western Carpathians
(Slovakia) mountains. The author found that males used stands at successive stages
in summer and autumn. The author related these tendencies with blueberry
cropping. While describing capercaillie habitats in Belarus, Немцев (1973) noted
33
that these birds were usually spread in dry coniferous and deciduous stands; were
rarely found in upland moors and were detected most rarely in young pine stands.
Meanwhile, stands of other types were avoided. In addition, the author emphasized
the differences of species composition of stands used by capercaillies in different
parts of the country: capercaillies were detected in marshy pine stands in the
northern part, and in mixed pine-oak and spruce-oak stands in the southern part.
Черкас (2008) referred to Гаврин’s distribution of forests into biocenoses and
grouped capercaillie habitats detected in the Bialowieza forest as follows: the
biggest number of capercaillies was detected in dry and marshy pine stands (39 %
and 35 %, respectively). A slightly fewer capercaillies were found in mixed spruce-
pine stands (21%) and the least number of capercaillies were detected in young
stands and clear-cuts (5%). According to Кириков (1975), capercaillies live in
wetlands because it is safer than in pine or spruce-broadleaf stands (Дацкевич,
1998; Губкин, 1968). Both the results of this study and the data obtained by other
authors show the diversity of stands used by capercaillies.
The results of the comparison of capercaillie habitats and random points
showed that the birds found a sufficient number of habitats of necessary stand
structure in Dzūkija. Meanwhile, the number of habitats was limited by forest
structure in Aukštaitija. The habitats used by males and females did not differ
essentially, except for the fact that females preferred young stands. This tendency
coincides with the results obtained by Rolstad (1989) and Saniga (2003). The fact
that males avoided young stands was also found in Norway (Borset and Kraft,
1973), Bavaria (Scherzinger, 1976) and Poland (Dzieciolowski and Matuszhewski,
1980). The preference of females to denser and younger stands was confirmed in
northern Sweden (Ekedahl, 2005). Authors explain this preference by the fact that
males are twice as big as females and moving around dense trees is more difficult
for them.
CONCLUSIONS
1. The proportion of pine stands in high occupancy leks up to 1 km from the
centre was bigger (p<0.05) if compared with low occupancy leks. High
occupancy leks were located about 500 m further from homesteads (the
difference p<0.0001) and 180 m further (p=0.09) from the forest edge, if
compared with low occupancy leks. Wetland proportions in high occupancy
leks at all analysed distances were 2.5-3 times (p<0.05) bigger than those in
low occupancy leks. The differences of stand areas of different forest types
were found only when comparing the areas located 1 km and 2 km in radii from
the lek centre (Task 1).
2. The distance of 0.5 km from the lek centre was the most significant for lek
selection by capercaillies. Lek selection in Dzūkija and Aukštaitija was
influenced by the following variables: low (0.5), medium (0.6-0.7) and high
(0.8-0.9) stocking level stands, proportion of pine, proportion of middle-age,
mature-overmature pine stands, wetlands, Ledo-sphagnosa and Vaccinio-
myrtillosa stands and core areas. The same forest structure variables
influencing lek selection were typical to high and low occupancy leks (Task 2).
34
3. The estimated annual home ranges of capercaillie male amounted to approx.
988.6 ha and varied depending on the time of the year. The largest range of
capercaillie male was estimated in summer-autumn period (aver. 388.3 ha).
This range amounted to 188 ha in winter and only to 49.1 ha in spring (during
the mating period) (Task 3).
4. The least distance from the lek to the centre of home range of male
capercaillie was detected in spring (aver. 0.71 km) and 2.7 km in winter.
During summer-autumn period, four males of six lived closer to the lek (4.7
km), while the remaining two males migrated much further from the lek (aver.
7.7 km). Capercaillie female lived 1.9 km from the lek in the summer period
(Task 3).
5. The majority of microhabitats of capercaillies males and females were
detected in dry and marshy biotopes of pine stands. Depending on sex, the time
of the year and the period of life, capercaillies used forests of diverse structure.
The needs of individual birds for habitats varied (Task 4).
6. Stand structure in capercaillie microhabitats and available landscapes in
Dzūkija did not differ significantly. Significant differences of stand structure in
Aukštaitija between capercaillie habitats and available landscapes showed that
lek selection was limited by the number of habitats of necessary structure. The
comparison of microhabitats of capercaillies of different sexes showed that
females used younger stands if compared with males (Task 4).
Further researches needs and directions
Studies revealed new directions for further studies. A lot of information about
radio-tagged birds and other capercaillies was collected during the fieldwork. The
data obtained during this study were used just partially. Information about social
behaviour of capercaillies, their activity phases within a day, reaction to human
disturbance, flying distances of flushed birds, including data on weather conditions
were collected during the observation of these birds.
Infrastructure variables as well as the presence of ecotones were recorded in
capercaillie locations. The coverage of underbrush, undergrowth, berry bushes and
grass cover was measured. The samples of needles from pines of different age
groups used by capercaillies for eating as well as needles from randomly selected
trees were collected. All these data could be used in further studies on
capercaillies, including studies on artificially bred capercaillies.
Landscape characteristics were defined in capercaillie leks located in two
different regions. Based on these results, the next stage of the research could be the
development of models that would help to detect the areas, which might have as
yet undiscovered leks. These models would be also useful in the process of letting
artificially bred capercaillies (re-acclimatization) to the areas where these birds
were extinct many years ago.
Studies on radio-tagged male capercaillies in Lithuania (the Labanoras forest)
and Belarus revealed that birds used different habitats. The biotopes used by the
male marked in Lithuania at different seasons were very similar: the bird was never
35
detected in spruce stands or mixed deciduous stands (unlike the capercaillies
tracked in Belarus). Although these results are difficult to compare and interpret
due to different data samples, the differences of habitats used by capercaillies can
be determined by different reaction of birds to habitat structure due to the
differences of stand species composition (the spread of aspen). Thus, further
detailed studies are necessary.
It was also difficult to ignore the fact that three capercaillie nests were
destroyed by ravens and eleven adult capercaillies (seven in Lithuania and four in
Belarus) were killed by predators were personally found during the collection of
material for these studies. Four of these birds were radio-tagged. Besides, one of
these birds was found under the electricity transmission line; therefore, the
predators could have found the already dead bird. Several other cases about
destroyed nests of capercaillies or when the birds were found killed by the
predators were reported by foresters or the employees of protected areas. Having
considered these facts, there is a need to study the annual influence of predators on
capercaillie population in the region (as well as in Lithuania). Actually, the number
of most predators (including wild boars, ravens and jays) has significantly
increased in recent decades (Zizas et al., 2012).
Proposals for capercaillie protection
The protection of leks should be based on a continuous specification of lek
occupancy level and location. In addition, it is necessary to systematically collect
data on new leks and extinction of old ones, as well as to collect data on
capercaillies observed in all seasons using a survey method by interviewing
foresters and the employees of protected areas (and other respondents).
Studies revealed that lek occupancy depends on a number of landscape
variables, i.e. the occupancy level of some leks declined or they became non-viable
(became extinct) through the change of landscape. Using the assistance of qualified
experts it is necessary to thoroughly study the environment of protected leks,
which are considered to be degraded and to determine the reasons of lek
degradation. Middle-aged and older pine stands adjacent to these leks should be
checked as potential landscapes, which could give shelter to these leks. Based on
study results, the environment of low occupancy leks could be arranged applying
the environmental management measures. These measures could be also used for
the accommodation of capercaillies grown in aviaries.
Aspen leaves is an important source of nutrition to capercaillies in summer-
autumn period. Inaccessibility of these tree species can have negative influence on
the abundance of capercaillies. Having considered these facts, stands with aspen in
the first layer should be formed in the forests, which are chosen by capercaillies for
living.
In the nature predators of capercaillies have a significant negative impact on the
abundance of these birds. The abundance of predators (martens, racoon dogs,
foxes) and corvidae (ravens and jays) should be regulated in capercaillie inhabited
forests and especially in lek surrounding. In addition, wild boar feeding places
36
should not be fitted near capercaillie leks and those already fitted should be
destroyed.
List of publications on the theme of the thesis
Zizas, Rytis; Shamovich, Dmitry; Kurlavičius, Petras; Belova, Olgirda and
Brazaitis, Gediminas. Radio-tracking of Capercaillie (Tetrao urogallus L.) in
North Belarus // Baltic Forestry, 2012. Vol. 18 (2), p. 270-277.
Zizas, Rytis; Belova, Olgirda; Brazaitis, Gediminas; Doftartė, Asta. Kurtinių
Tetrao urogallus L. populiacijos gausos kaita ir miško struktūra jų buveinėse //
Miškininkystė, 2012, Nr. 2(72), p. 47-54.
Reports in scientific conferences:
Zizas, Rytis. Kurtinių (Tetrao urogallus L.) ir tetervinų (Tetrao tetrix L.)
tuokviečių aplinkos bei galimo plėšrūnų poveikio šių paukščių dėtims tyrimai
Lietuvoje. Jaunųjų mokslininkų konferencija „Žaliosios laboratorijos 2009“.
2009 m. rugsėjo 17-18 d. Lietuvos miškų institutas.
Zizas, Rytis. Kurtinių (Tetrao urogallus L.) paplitimas, gausumas ir tuokviečių
aplinkos tyrimai Lietuvoje. 17-oji tarptautinė mokslinė-praktinė konferencija
„Žmogaus ir gamtos sauga 2011“. 2011 m. gegužės 11-13 d., birželio 16-18 d.
Konferencijos medžiagos 2-oji dalis. Akademija, p. 70-73.
Belova, Olgirda; Gedminas, Artūras; Lynikienė, Jūratė; Zizas, Rytis.
Bestuburių bei stuburinių gyvūnų potencialūs migraciniai keliai Lietuvos ir
Baltarusijos pasienio miškų ekosistemose // „Agrariniai ir miškininkystės
mokslai: naujausi tyrimų rezultatai ir inovatyvūs sprendimai“. Girionys. 2013.
Nr. 3, p. 56-58.
Zizas, Rytis. Grouse in Dzūkija. Tarptautinė konferencija „Spatial Distribution
of the Invertebrate and Vertebrate Animals and Their Present and Possible
Migratory Paths in the Forest Ecosystems of Lithuanian-Belarusian
Transboundary Areas“. Lietuva. 2011.
Zizas, Rytis. The researches of capercaillie (Tetrao urogallus L.) populations
and the migration corridors in Transboundary Zone of Lithuania and Belarus.
Tarptautinė konferencija „Spatial Distribution of The Invertebrate and
Vertebrate Animals and Their Present and Possible Migratory Paths in The
Forest Ecosystems of Lithuanian-Belarusian Transboundary Areas“. Lietuva.
2012.
Zizas, R. Bukauskaitė, J. Capercaillie and Black Grouse in Lithuania.
Necessity of creation the ecological corridors between subpopulations T.u.
Major. Tarptautinis seminaras. 2014 m. kovo 24-25 d. Lenkijos Mokslų
Akademijos centras. Wiežba. Lenkija.
37
REZIUMĖ
Darbo aktualumas. Kurtinių gausos mažėjimas pastaraisiais dešimtmečiais
stebimas didžiojoje jų natūralaus paplitimo arealo dalyje. Rūšiai grėsmė išnykti
kyla vakarų, centrinėje ir pietrytinėje Europos dalyse (Storch, 2007). Dėl šios
priežasties kurtiniai įtraukti į Europos Sąjungos Paukščių direktyvos I priedo rūšių
sąrašą (EU, 2010), Tarptautinę raudonąją knygą (IUCN 2012). Nuo 1989 m. ši
rūšis įrašyta ir į Lietuvos raudonąją knygą (Rašomavičius, 2007), priskiriama II
(sparčiai nykstanti rūšis) retumo kategorijai. Šių dokumentų pagrindu kurtinių
apsaugai mūsų šalyje įsteigtos 8 Paukščių apsaugai svarbios teritorijos (PAST) ir
saugomos visos žinomos šių paukščių tuokvietės. Naujausiais duomenimis, mūsų
šalyje yra iki 450 kurtinių patinų (Kurtinio apsaugos planas, 2012).
Lietuva yra pietvakariniame ištisinio kurtinių paplitimo arealo pakraštyje.
Europos pietvakariuose rūšis paplitusi fragmentiškai. Dėl šios priežasties būtina
tinkamai užtikrinti kurtinių buveinių apsaugą Lietuvoje, siekiant išvengti
populiacijos izoliuotumo. Be to, Lietuvoje dažnai kyla tuokviečių stabilumo
problemų. Nors tas pačias tuokvietes paukščiai paprastai naudoja ilgą laiką, dėl
vienokių ar kitokių priežasčių jų dislokacijos vieta dažnai keičiasi. Miškininkaujant
saugomos visos nuo seno žinomos tuokvietės, nors paukščiai kai kuriomis seniai
nesinaudoja. Pasikeitusi miško struktūra gali būti viena iš priežasčių, dėl kurios
tuokvietės ilgainiui yra apleidžiamos.
Paukščių gausumas priklauso nuo natūralių ir antropogeninių faktorių,
veikiančių keliuose erdvinės skalės lygmenyse. Naujausi tyrimai rodo, kad
kurtinys, kaip siaurai specializuota ir medyno erdvinei struktūrai reikli rūšis (Kurki
and Lindén, 1995; Kurki et al., 2000; Graf, 2005), jautriai reaguoja ir į
kraštovaizdžio lygmens buveinės pokyčius. Daugelyje šalių naudojami įvairūs
kurtinių apsaugos būdai, nes nežinoma, kokie konkretūs buveinės požymiai
kraštovaizdžio lygmenyje galėtų kurtiniams sukurti palankias sąlygas. Nors Vakarų
Europos šalyse kurtiniai, kaip teigiama, yra viena iš geriausiai ištirtų paukščių
rūšių (Storch, 2007), tyrimų rezultatai ne visur gali būti pritaikomi dėl skirtingų
geografinių, ekologinių sąlygų ar miškininkavimo ypatumų.
Mūsų šalyje kurtinių biologija ir ekologija detaliau tyrinėta V. Logmino prieš
daug dešmtmečių (1962). Vėliau daugiausia apsiribota tik kurtinių tuokviečių
išsidėstymo nustatymu ir vietinių populiacijų gausos stebėsena PAST teritorijose ir
už jų ribų. Tad realią kurtinių būklę gali parodyti tik sistemingi ir metodiškai
pagrįsti tyrimai (Kurtinio apsaugos planas, 2012). Iki šiol nėra atlikta išsamių
ekologinių tyrimų, kurie nurodytų kurtinių buveinių medynų struktūros, ir
kraštovaizdžio lygmenų charakteristikas. Šiame darbe pagrindiniai tyrimai sutelkti
į du erdvinės skalės lygmenis: medynų struktūros (kurtinių mikrobuveinių) bei
kraštovaizdžio (makrobuveinių). Tikimasi, kad gauti rezultatai padės identifikuoti
esamas ir kylančias grėsmes vietinėms kurtinių populiacijoms ir sąlygos galimybę
parengti tikslesnes apsaugos priemones šiems paukščiams apsaugoti.
Disertacinio darbo tikslas - nustatyti kurtinių tuokviečių pasirinkimo
ypatumus, miško struktūrą sezoniškai naudojamose buveinėse ir individualių
gyvenamųjų teritorijų dinamiką priklausomai nuo metų laiko.
38
Uždaviniai:
1. Išanalizuoti miško kraštovaizdžio stuktūros įtaką kurtinių tuokviečių užimtumui
ir įvertinti tarpregioninius miško struktūros skirtumus.
2. Nustatyti tuokviečių pasirinkimą sąlygojančius miško struktūros elementus ir
įvertinti pasirinkimui reikšmingą atstumą.
3. Ištirti kurtinių individualių gyvenamųjų teritorijų dydį ir nuo tuokviečių esantį
atstumą, kuriuo šie paukščiai gyvena skirtingu metų laiku.
4. Išanalizuoti miško struktūrą kurtinių mikrobuveinėse, naudojamose skirtingu
metų laiku.
Svarbiausi ginamieji teiginiai:
Kurtinių tuokviečių užimtumą sąlygoja miško struktūra.
Kurtiniai pasirinkdami vietas tuoktuvėms pirmenybę teikia retiems, šalia pelkių
augantiems vyresnio amžiaus pušynams.
Kurtiniai patinai gyvena nevienodu atstumu nuo tuokviečių. Šių paukščių
individualių gyvenamųjų teritorijų dinamika priklauso nuo metų laiko ir
gyvenimo tarpsnio.
Kurtiniai priklausomai nuo metų laiko ir lyties naudoja skirtingas buveines.
Mokslinis naujumas ir praktinis pritaikymas
Pirmą kartą Lietuvoje išanalizuotas kurtinių tuokviečių pasirinkimas bei
nustatyta tuokviečių užimtumo priklausomybė nuo miško kraštovaizdžio
struktūros. Pirmą kartą Lietuvoje ir Baltarusijoje vykdyti kurtinių buveinių
naudojimo ir judėjimo buveinėse tyrimai, taikant paukščių individualaus sekimo
metodą.
Nustatyti kurtinių ekologijos ypatumai iš esmės papildo teorines žinias apie
šios rūšies ekologijos specifiką pietvakariniame ištisinio paplitimo arealo
pakraštyje. Gauti rezultatai taikytini tolesniuose šios rūšies paukščių sąveikos su
aplinka moksliniuose tyrimuose. Gauti mikrobuveinių naudojimo skirtingais metų
laikais duomenys taikytini papildant miško kirtimo taisykles, reglamentuojančias
miško naudojimą kurtinių tuokviečių apsaugos zonose. Ištirti kurtinių tuoktuvių
buveinių poreikiai padėjo ir ateityje padės nustatyti dar nežinomas tuokvietes bei
efektyviau planuoti kurtinių populiacijos apsaugą Lietuvoje.
Darbo apimtis ir struktūra. Disertaciją sudaro įvadas, literatūros analizė,
darbo metodika, tyrimų rezultatų skyriai, išvados, tolesnių tyrimų reikalingumas ir
kryptys, literatūros sąrašas, disertacijos tema skelbtų publikacijų sąrašas, darbe
naudotų santrumpų sąrašas ir priedai. Darbo rezultatai išdėstyti 3 skyriuose.
Literatūros sąraše yra 193 šaltiniai. Bendra disertacijos apimtis – 119 puslapių.
Tekstą iliustruoja 15 lentelių ir 57 paveikslai; 3 priedų apimtis – 4 p.
39
IŠVADOS
1. Aukšto užimtumo lygio tuokvietėse pušynų dalis iki 1 km atstumu nuo centro
didesnė (p<0,05) negu žemo užimtumo. Aukšto užimtumo lygio tuokvietės
išsidėsčiusios apie 500 m toliau (skirtumas p<0,0001) nuo sodybų ir 180 m toliau
(p=0,09) nuo miško pakraščio negu žemo užimtumo tuokvietės. Pelkių plotai visais
tirtais atstumais aukšto užimtumo lygio tuokvietėse buvo 2,5–3 kartus (p<0,05)
didesni negu žemo užimtumo. Skirtingų miško tipų medynų plotų skirtumai
nustatyti tik lyginant 1 km ir 2 km spinduliais nuo tuokvietės centro esančias
teritorijas (1 uždavinys).
2. Reikšmingiausias kurtiniams pasirenkant tuokvietes buvo 500 m atstumas nuo
jų centro. Pasirenkant tuokvietes Dzūkijoje ir Aukštaitijoje turėjo įtakos mažo
(0,5), vidutinio (0,6–0,7) ir didelio skalsumo (0,8–0,9) medynų plotai, pušies dalis
medyne, pusamžių, brandžių ir perbrendusių pušynų, pelkių plotai, Ledo-
sphagnosa ir Vaccinio-myrtillosa miško tipų medynų plotai. Tie patys pasirinkimą
sąlygojantys miško struktūros elementai buvo būdingi aukšto ir žemo užimtumo
lygio kurtinių tuokvietėse (2 uždavinys).
3. Apskaičiuotas metinis kurtinio patino individualios gyvenamosios teritorijos
dydis vidutiniškai buvo 988,6 ha ir keitėsi priklausomai nuo metų laiko. Vasaros–
rudens laikotarpiu individuali teritorija buvo didžiausia (vidutiniškai 388,3 ha);
žiemą – 188 ha, o pavasarį (tuoktuvių laikotarpiu) tik 49,1 ha (3 uždavinys).
4. Mažiausias atstumas nuo tuokvietės iki kurtinių patinų individualios teritorijos
centro buvo pavasarį (vidutiniškai 0,71 km) ir žiemą – 2,7 km. Vasaros–rudens
laikotarpiu 4 patinai (iš 6) gyveno arčiau tuokvietės (4,7 km), o kiti 2 patinai
migravo žymiai toliau – vidutiniškai 7,7 km atstumu. Kurtinio patelė vasaros
laikotarpiu gyveno 1,9 km atstumu nuo lizdo (3 uždavinys).
5. Žiemą ir pavasarį dauguma abiejų lyčių kurtinių mikrobuveinių aptikta sausų,
pelkėtų ir pelkinių pušynų biotopuose. Kurtiniams priklausomai nuo lyties metų
laiko ir gyvenimo tarpsnio reikalingi labai skirtingos struktūros miškai. Individų
poreikiai buveinėms nevienodi (4 uždavinys).
6. Dzūkijoje kurtinių mikrobuveinėse ir galimose teritorijose medynų struktūra
patikimai nesiskyrė. Aukštaitijoje nustatyti patikimi medynų struktūros skirtumai
tarp kurtinių mikrobuveinių ir galimų teritorijų rodo, kad mikrobuveinių
pasirinkimą riboja tinkamos struktūros buveinių kiekis. Lyginant lyčių
mikrobuveines nustatyta, patelės naudojo jaunesnius medynus nei patinai (4
uždavinys).
40
Acknowledgements
I would like to thank to my scientific advisor prof. Gediminas Brazaitis for his
trust in me to plan and execute my master’s and PhD thesis independently and his
valuable contribution in data processing.
I would also like to thank to prof. Petras Kurlavičius and Dmitry Šamovič for
the opportunity to collaborate in the capercaillie research in Belarus; to all
biologists of the protected areas and foresters of state Forest Enterprises (especially
Švenčionėliai) who provided the data of capercaillies, helped in field works and
provided the accommodation. I would also like to thank to prof. Gintautas
Mozgeris and dr. Virgilijus Baliuckas for statistical and GIS analysis, and to all the
people, who have helped to review this thesis. Thanks to my colleagues of the
Institute of Forestry, Forest Protection and Game Management Department for
friendship, support and technical assistance.
The Research Council of Lithuania funded useful scientific internships in
Belarus, Russia, Finland and Italy. I would also like to thank to all the scientists
who have kindly accepted me to the internships. Some part of telemetry equipment
was granted by IDEA WILD.
I’m very grateful to my family for their understanding, support and patience.