Distribúcia a hustota výra
skalného (Bubo bubo) v Nitrianskej
pahorkatine a Hornonitrianskej kotline
(západné Slovensko) v rokoch 2013 – 2017
Distribution and density of the Eurasian Eagle-owl (Bubo
bubo) in the Nitrianska pahorkatina Hills
and the Hornonitrianska kotlina Basin (W
Slovakia) in 2013–2017
Ladislav ŠNÍRER, Stanislav HARVANČÍK & Andrej
DÚBRAVSKÝ
Horská 1314/42, 95806 Partizánske, Slovensko;
e-mail: snirer@pobox.sk
Štátna ochrana prírody SR, Správa Chránenej
krajinnej oblasti Ponitrie, Samova 3, 949 01 Nitra,
Slovensko
Strojárenská 198, 95801 Partizánske, Slovensko
Abstract: Breeding population of the Eurasian
Eagle-owl (Bubo bubo) is localized mainly in
marginal parts and foothills of Tribeč Mts.,
Považský Inovec Mts. and Strážovské vrchy Mts. In
2013–2017 we checked 72 sites (in study area 1440
km2) and found 30 breeding pairs (i.e. density 2.1
pairs/ 100 km2. Altogether we recorded 81 breeding
attempts, of them 57 successful and 118 chicks (11
nests with 1 chick, 32 with 2, 13 with 3 a 1
with 4 chicks). We analysed distribution and density
of nests according to habitats (abandoned stone
quarries, active stone quarries, rocky slopes, tree
nests in forest, buildings). The abandoned stone
pits was the best habitat (in the sense of chick
number; 45 successful nests of 59 nests = 76.3%),
when 91 chicks fledged (77.1% of all fledged
chicks). Based on this study we can conclude that
the population was stable within the study period.
Početnosť zimujúcich vodných vtákov
na severe Slovenska počas januárov 2014 – 2018
The number of wintering waterbirds in northern
Slovakia in Januaries 2014–2018
Michal BALÁŽ, Dušan KARASKA, Matej REPEL
Katedra biológie a ekológie, Pedagogická fakulta
Katolíckej univerzity, Hrabovská cesta 1, 034 01
Ružomberok, Slovensko; e-mail: michal.balaz@ku.sk
Štátna ochrana prírody SR, Správa CHKO Horná Orava,
Bernolákova 408, 029 01 Námestovo, Slovensko;
e-mail: dusan.karaska@sopsr.sk
Slovenská ornitologická spoločnosť/BirdLife
Slovensko, Námestie osloboditeľov 1, 071 01
Michalovce, Slovensko; e-mail: repel@vtaky.sk
Abstract. The structure of wintering
waterbird assemblages is highly affected by the
temperature. Wintering birds are not able to find
enough food during the cold winters and they have to
migrate to areas with better conditions. During the
Januaries 2014–2018 44 (yearly 23–34) water bird
species were registered in three regions of Northern
Slovakia. The overall number of wintering birds
ranged from 9125 to 12,639. There was found the
significant impact of the temperature on the number
of diving ducks. Mainly the Common Merganser and the
Common Goldeneye significantly increased their
numbers in winters with lower temperature. The most
prominent influence between temperature and the
number of wintering birds was found in last two
Januaries (2017 and 2018) which were significantly
different in average temperature. January 2017 was
about 8.5 °C colder than January 2018 and many
wintering localities were frozen. Despite this fact
the number of wintering birds in 2017 was higher
than in 2018. However, the number of species has
decreased in 2017. The most of the differences were
caused by the changing numbers of diving ducks which
had to leave traditional wintering sites in northern
parts of Europe during cold winter of 2017.