Page 24 - NZDPM 33/2017

НАУКОВІ ЗАПИСКИ ДЕРЖАВНОГО ПРИ РОДОЗНАВЧОГО МУЗЕЮ
Випуск 33 Львів, 2017 С. 23-32

УДК 591.5:598.244]:911.5(477.41/.42)

Bokotey A., Strus Iu., Dzubenko N.

NESTING HABITATS OF BLACK STORK (CICONIA NIGRA L.) IN UKRAINIAN
FOREST ZONE (POLISSIA) REVEALED BY AN OVERLAY ANALYSIS IN GIS

The study was based on an overlay analysis in GIS. Exact locations of 108 nest and layers
representing forest types, prevailing tree species, forest age and productivity (bonitet class)
were used. The analysis was performed on the level of individual nests (spatial join to point
layer), and on the level of buffers with 500m radius around nests. To find the most preferable
forest types for Black Stork we compared the frequency of distribution of forest types on the
nesting territories with the frequency of distribution of those types in the study area and in
500m buffers around 108 random points.
According to the results of our research, the spatial distribution of Black Stork nests to a
great extant follows the general structure of forests in the region. We found some selectivity in
case of wet forest types with prevalence of oak with pine, as well as with black alder, but the
result is not statistically significant. The only statistically significant relation was found in
case of forest age. Black Storks prefer old and mature forests. The most important trees for
nesting were oak (53,3%) and pine (29,9%).
Keywords: Black Stork, Ciconia nigra, habitats, GIS.

Introduction

Conservation of any species is usually impossible without protection of habitats
important for their breeding, foraging, resting etc. Black Stork is one of most habitat-
dependent species of birds in Europe, because it is strongly dependent on the availability of
mature forests and trees with a low level of disturbance. There is a large number of papers
devoted to Black Stork habitat preferences in Europe. Most of them are based on the studies
made in Central and East European countries [1, 4, 7, 11, 12 etc.], mostly Baltic countries,
which is reasonable, taking into account the species distribution in Europe and the sizes of
national populations [2, 10].
Ukraine possesses a significant part of the European Black Stork population [2, 10] and
is interesting as a territory of breeding range margin, where European Forest zone borders
with steppes. The Ukrainian population may be underestimated and might actually be much
bigger. No detailed studies of Black Stork breeding habitats in Ukraine have been
conducted so far. Some generic works [5, 17, 17, 20 etc.] with the topic-related information
have been published, yet there is a lack of specialized studies. One study [14] was related to
habitats and their changes but was mostly analytical and based on expert opinions without
appropriate raw numerical data. Current publication aims to fill some of gaps in this area of
Black Stork studies using GIS approach.

Materials and Methods

The analysis of Black Stork spatial distribution in relation to forest habitat types was
performed in the territories of eight forestry companies (table 1) in the Rivne region of
Ukraine, which overlap with the Polissya nature zone and with the kernel of Black Storks
highest population density, as well as with the main part of the breeding range of this
species in Ukraine (fig. 1). The territories of other forestry companies in the region and
known nesting locations from other parts of Ukrainian Polissya have not been covered by
the analysis, because it was not possible to obtain databases of their forest structure so far.