Slovak Raptor Journal 2011, 5: 121–126. DOI: 10.2478/v10262-012-0058-7. © Raptor Protection of (RPS)

The abundance of the little owl (Athene noctua) in Podunajská rovina lowland in 2009 and 2010 Početnosť kuvika obyčajného (Athene noctua) na Podunajskej rovine v rokoch 2009 a 2010

Martin DOBRÝ

Abstract: This paper outlines the results of the mapping of the little owl and its abundance in selected areas in Podunajská rovina lowland, Slovakia, in 2009 and 2010. From a total area of 3,500 km2, 11.6% was monitored and 26 occupied localities identified. Average abundance was 0.6 occupied localities per 10 km2. Abstakt: Práca informuje o výsledkoch mapovania výskytu kuvika obyčajného na území vybraných častí Podunajskej roviny v rokoch 2009 a 2010. Z celkovej rozlohy Podunajskej roviny (3500 km2) bola zmapovaná plocha približne 11,6 %, kde bolo zistených 26 obsadených lokalít. Priemerná abundancia bola 0,6 obsadených lokalít na 10 km2.

Key words: population density, distribution, Slovakia.

Martin Dobrý, Raptor Protection of Slovakia, Kuklovská 5, SK–841 04 Bratislava 4, Slovakia. E-mail: [email protected]. Acknowledgement: I thank Ivan Dobrý, Zuzana Kesanová, Roman Kormoši and Zoltán Vozák for their help with the field work. Special thanks go to Marcel Uhrin for his encouragement. The study was supported by the grant scheme of the Small Member Projects 2010 of the Raptor Protection of Slovakia and by the European Regional Development Fund within the Slovak-Austrian cross-border cooperation programme 2007–2013 (project CORO-SKAT N00103).

Introduction and strengthen populations within Slovakia, are ongoing. Populations of the little owl in Central Europe have de- The most common causes of the decline include the be creased significantly over the last 50 years, much more loss or unavailability of trophic sources, loss of breeding so than for any other owl species (Glutz von Blothzheim and day roosting sites, direct human disturbance at nests, & Bauer 1994). In Germany, a population decline of 24% collisions with vehicles, severe winters with long-lasting and in Poland 50% (Nieuwenhuyse et al. 2008) were not- snow cover, predation pressure and a significant number ed between 1994 and 2004. Decreasing populations in of owls also perish when trapped in drainpipes, chimneys the Czech Republic and in large unoccupied areas in the and the like (Šťastný et al. 1987, Sedláček 1988, Schönn north of Slovakia have, in recent years, shown that little et al. 1991, Glutz von Blotzheim & Bauer 1994, Hage- owls in the lands of the former are also meijer & Blair 1997, Pačenovský 2002, Závalský 2004, under continued pressure. Compared with the beginning Nieuwenhuyse et al. 2008). of the millennium, in 2011 further declines in populations The main aim of this study was to estimate the popu- in open agricultural land in the Czech Republic were also lation size of the little owl in the south-west of Slovakia, found. This negative trend in abundance is also apparent based on the results recorded in selected parts of Podunaj- from “distribution centres“, where the little owl used to ská rovina lowland, and to contribute to the knowledge of attain relatively high population density rates. The pre- overall abundance of the species in Slovakia. sent population of the little owl in the Czech Republic does not exceed 180 breeding pairs (2010–2011; Šálek Study area & Schröpfer 2011, pers. comm.). The absence of up-to- Podunajská rovina lowland, with the exception of a small -date data on the abundance and number of the little owl in area in the north-west, is one of the driest and warmest Slovakia, has prompted a renewed interest in the species. climatic zones in Slovakia. In the north of Podunajská Identifying the key areas of abundance and setting up rovina lowland, the influence of the Malé Karpaty Mts. is adequate protection measures for this owl, in order to save apparent and causes the climate to be slightly more humid

121 Dobrý M: The abundance of the little owl (Athene noctua) in Podunajská rovina lowland in 2009 and 2010

and colder than the rest of the region. The warmest area Material and methods lies around Veľký Meder, where the average annual tem- Data were gathered on four model areas in Podunajská perature is more than 10 °C. In other parts of Podunajská rovina lowland with the overall area of 406.9 km2 (Figure rovina lowland, the average annual temperature does not 1) during spring seasons (from March 10 to May 9) in the exceed this figure. The average air temperature in January years 2009 and 2010. A standardised method of mapping is usually -1 °C to -2 °C, in July it is more than 20 °C. was used with the help of territorial call recordings, which Annual rainfall reaches 600 mm, while approximately were played from a car radio. Mapping was carried out 300–350 mm falls during the growing season (Veľký after sunset (earliest time just after dusk) to approximately 1980). The most important element in land structure in 23:00. Three minutes of playing recordings were followed the model areas is arable land, which comprises 57.5% by two minutes of listening. Recordings were then played to 80.1 % of the whole territory. The remainder is com- once more for two minutes. If there were no responses posed of vineyards, gardens, orchards, grasslands, forests, from little owls after another five minutes of listening, water surfaces, built-up areas and the other surfaces, with the area was considered unoccupied. Farmyards were relatively equal representation (ÚGKK SR 2010). The not visited directly, rather recordings were only played typical land-use of Podunajská rovina lowland is depicted close by. Some areas were checked in both of the years in Figure 2. the mapping took place. An area where the species was

Fig. 1. Location of model areas in the southwest of Slovakia. 1 – residence/settlement/site, 2 – geographic unit boundary, 3 – model area 1, 4 – model area 2, 5 – model area 3, 6 – model area 4. Obr. 1. Poloha modelových plôch v rámci juhozápadného Slovenska. 1 – sídlo, 2 – hranica geografického celku, 3 – modelová plocha 1, 4 – modelová plocha 2, 5 – modelová plocha 3, 6 – modelová plocha 4.

122 Slovak Raptor Journal 2011, 5: 121–126. DOI: 10.2478/v10262-012-0058-7. © Raptor Protection of Slovakia (RPS) found in at least one year, was considered occupied. When Results a little owl responded, the recording was terminated at Out of 79 controlled areas, 26 were occupied in at least one once and the area considered occupied. Field work was of the mapping years. The overall proportion of occupied done only in favourable weather conditions (without rain areas was 32%. The abundance of the species was record- and wind). ed in individual model areas 0.2 (model area 3), 0.4 (4), Agricultural areas (Figure 2), farms, isolated buildings 0.7 (1) and 1.2 (2) in occupied locality per 10 km2. The in farmland and other closed areas, occasionally also ce- average abundance was 0.6 occupied localities per 10 km2. meteries, castles, parks and ruins, were all mapped. A total The highest value was recorded in model area 2, on Žitný of 79 localities were checked. The overview of cadastral ostrov, the boundaries of which are formed by cadastral districts composing the model areas is in the Table 1. area Janíky in the north, Oľdza in the east, in the south and Miloslavov in the west. In this region two cadastral areas lacked positive records. In model area 1, Tab. 1. Overview of model areas and numbers of monitored and around the town of Šaľa, the abundance rate was 0.7 of occupied sites. 2 Tab. 1. Prehľad mapovaných plôch a počtov kontrolovaných an occupied area per 10 km and one cadastral district a obsadených lokalít was without a positive response. The model area 3 with the lowest abundance rate and only one positive locality the number of surveyed / was situated on the outskirts of Bratislava. The highest cadastral district / occupied sites rate of two occupied areas per one cadastral district was katastrálne územie počet kontrolovaných / obsadených lokalít recorded 6 times, one occupied area per a cadastral dis- area / plocha 1 [153.9 km2] 27 / 10 trict was registered fourteen times and in eight cadastral Diakovce 3 / 1 districts the presence of the species not confirmed at all. Kráľová nad Váhom 3 / 2 All localities with positive occurrence were of anthropic Tešedíkovo 2 / 2 character – agricultural areas. Occurrence in parks, gar- Žihárec 3 / 2 dens and in open land was not confirmed. Šaľa 7 / 0 Podunajská rovina lowland covers more than Dlhá nad Váhom 2 / 1 3,500 km2, of which the mapped area comprised Topoľnica 3 / 1 406.9 km2 (11.6%). Based on the results from this area Kajal 4 / 1 in the years 2009 and 2010, it is possible to estimate the area / plocha 2 [83.7 km2] 26 / 10 total number of sites occupied by the little owl as appro- Štvrtok na Ostrove 2 / 1 ximately 217. Čakany 1 / 0 Dolné Janíky 1 / 0 Discussion Horné Janíky 2 / 1 Due to the use of indirect detection methods to establish 3 / 1 the little owl population size, it is necessary to consider Oľdza 2 / 1 the assessment of the population in the area as relative 2 / 1 (Townsend et al. 2008). Between 800 to 1,000 pairs of Kvetoslavov 4 / 1 7 / 2 little owl were estimated in Slovakia in 2002 (Pačenov- Miloslavov 2 / 2 ský 2002), a figure which corresponds well with the 217 area / plocha 3 [44.1 km2] 7 / 1 occupied localities in Podunajská rovina lowland in 2009 Rusovce 4 / 1 and 2010. Nevertheless, it should be noted, that since Čunovo 3 / 0 only specifically characterized locality types were used area / plocha 4 [125.0 km2] 19 / 5 for presence monitoring of the species, within the model Čiližská Radvaň 3 / 0 surfaces, the calculation may be slightly understated. Ňárad 1 / 1 Suitable comparative data from Podunajská rovina Boheľov 2 / 0 lowland are not available. In an area of 10×2 km in Du- Baloň 2 / 0 najská Streda district in 1992, at least 7–8 territories of Pataš 2 / 1 little owl were identified, which equates to 3.8 breeding Padáň 3 / 1 pairs per 10 km2 (Kürthy & Kürthyová, in Danko 1994). Dolný Štál / Horný Štál / Tône 4 / 2 It is unclear, whether this was a locally high value or, Sap 2 / 0 compared to more recent results, was an usually high

123 Dobrý M: The abundance of the little owl (Athene noctua) in Podunajská rovina lowland in 2009 and 2010

figure for the Podunajská rovina lowland at the beginning cies (Schönn et al. 1991, Ille 1992, Benda & Marek 2001, of 1990´s. As a comparison, in 1991 in Východoslovenská Nieuwenhuyse et al. 2008, Šálek & Schröpfer 2008). nížina lowland, an area of 1,306 km2, the density of one Sometimes, numbers can be even several times higher. nesting pair per 9.5 km2 was registered, that is, 250 nesting For instance, in 2000 in Děčín, Czech Republic, a local pairs. A similar situation occurred in Košická kotlina (both concentration of the species with density of 16.8 pairs per in east Slovakia; Danko et al. 1994). However, it seems 10 km2 was estimated, whereas the species was absent unlikely, that the density in Podunajská rovina lowland from the surrounding country (Benda & Marek 2001). In was higher than in Východoslovenská nížina lowland in the Austrian part of Pomoravie in 1991, 7 breeding pairs the beginning of the 1990’s. were found (with 4 other territories occupied by single Therefore, that figure probably relates to a local con- males), which were all concentrated in neighbouring centration, which is not unusual amongst populations of village, with one exception (Ille 1992). little owl in neighbouring countries (Czech Republic, The population density of the little owl in secondary Austria) or indeed elsewhere across the range of the spe- habitats in Central Europe, does not reach such significant M. Dobrý

Fig. 2. Typical landscape in Podunajská rovina lowland (Hviezdoslavov; above) and breeding sites of the little owl (Farm Kráľová nad Váhom; below), typical mapping site. Obr. 2. Typická krajina Podunajskej roviny (Hviezdoslavov; hore) a ukážka hniezdiska kuvika obyčajného (poľnohospodárske družstvo Kráľová nad Váhom; dole), typickej mapovanej lokality.

124 Slovak Raptor Journal 2011, 5: 121–126. DOI: 10.2478/v10262-012-0058-7. © Raptor Protection of Slovakia (RPS) figures than in its fundamental habitats of savannahs and References semi-deserts (Schönn et. al. 1991), although locally high Benda P & Marek J 2001: Početnost sýčka obecného values can be attained. Densities reached in research (Athene noctua) v Dečíne v roce 2000 [Abundance of areas do not come close to densities obtained in the little owl (Athene noctua) in Děčín, Czech Republic, current centres of distribution in Europe. For example, in 2000]. Buteo 12: 135–137. [In Czech with English in Portugal, the density within one open woodland in summary] 1997–1999, was 70 pairs per 10 km2, locally even 185 Chrenková M & Dobrý M 2010: Žije ešte u nás kuvik? pairs per 10 km2 and 25 pairs per 10 km2 in steppes (Tomé Výzva k spolupráci [Does the little owl still occur in et al. 2008). Despite this, however, compared to other your area? – Call for cooperation]. Dravce a sovy 6(2): neighbouring regions, the population of the Podunajská 24–25. [In Slovak with English summary] rovina lowland is not insignificant. In the geographical Danko Š 1994. Správa o činnosti skupiny pre výskum entities of Borská nížina lowland, Dolnomoravský úval a ochranu dravcov a sov v ČSFR za rok 1992 [Report lowland and Chvojnická pahorkatina Mts, 52 areas were on the Activity of the Group for Research and Protec- checked in 2011, out of which only one was occupied tion of Birds of Prey and Owls in Czechoslovakia in by a breeding pair (Dobrý et al., unpublished data). The 1992]. Buteo 6: 121–151. [In Slovak with English low population abundance in these areas, in comparison summary] with Podunajská rovina lowland, was also recorded in Danko Š, Diviš T, Dvorská J, Dvorský M, Chavko J, the early 1990’s (Kürthy pers. comm.). In the 840 km2 Karaska D, Kloubec B, Kurka P, Matušík H, Peške area of Nitrianska pahorkatina Mts, the density in 2009 L, Schröpfer L & Vacík R 1994. Stav poznatkov was 0.27 pairs per 10 km2. From 103 localities that were o početnosti hniezdnych populácií dravcov (Falconi- checked, 24 were occupied (Šnírer et al. 2009). The state formes) a sov (Strigiformes) v Českej a Slovenskej of the population in the neighbouring Austrian areas in republike k roku 1990 a ich populačný trend v rokoch 2010 was 74 occupied territories, all of them in the north 1970–1990 [The state of knowledge of breeding -eastern part of the country (thus partly in touch with numbers of birds of prey (Falconiformes) and owls Podunajská rovina lowland, Ille 2011, pers. comm.). In (Strigiformes) in the Czech and Slovak Republics as regard to information from surrounding regions, it will of 1990 and their population trends in 1970–1990]. be necessary to pay due attention to the protection of Buteo 6: 1–89. [In Slovak with English summary] the little owl population in Podunajská rovina lowland. Glutz von Blotzheim UN & Bauer KM 1994. Handbuch The importance of the local population for this region is der Vogel Mitteleuropas Band 9, Columbiformes evident and new data can be expected due to the ongoing – Piciformes, 2. durchgesehene Auflage. Aula-Verlag. monitoring work (Chrenková & Dobrý 2010). Podunajská Wiesbaden, 1150. rovina lowland, in terms of climatic conditions (tempe- Hagemeijer EJM & Blair MJ 1997. The EBCC atlas rature, precipitation), is the most suitable region for the of European breeding birds: Their distribution and little owl in Slovakia, and higher densities are likely, due abundance. TA Poyser. London, 903. to similar climatic conditions and more extensive farming, Ille R 1992. Zur Biologie und Ökologie des Steinkauzes only in Východoslovenská nížina lowland. A similar (Athene noctua) im Marchfeld: Aktuelle Situation und state, where after an overall decline populations of little mögliche Schutzmassnahmen. Egretta 35: 49–57. owl persist in parts of the country with the most suitable Nieuwenhuyse DV, Génot J-C & Johnson DH 2008. The climatic conditions, is known, for example, from Austria little owl – conservation, ecology and behavior of (Nieuwenhuyse et al. 2008). Athene noctua. University Press, Cambridge, 628. As was presumed, research failed to prove the presence Pačenovský S 2002: Kuvik obyčajný / Kuvik plačlivý of the species in types of localities other than farmyards. (Athene noctua) [The Little owl (Athene noctua)] A strong synanthropization of the species was already 367–369. In: Danko Š, Darolová A & Krištín A (eds) suggested some 20 years ago from Východoslovenská 2002: Rozšírenie vtákov na Slovensku [Birds Distri- nížina lowland (Danko et al. 1994). A conclusive report bution in Slovakia]. Veda, Bratislava, 680. [In Slovak on the little owl breeding in open landscapes in Slovakia with English summary] is not available at the present time. Sedláček K (ed) 1988: Červená kniha ohrožených a vzác- ných druhů rostlin a živočichů ČSSR 1 – Ptáci [The red book of endangered and rare species of plants and animals ČSSR 1 – birds (The Czechoslovak Socialist

125 Dobrý M: The abundance of the little owl (Athene noctua) in Podunajská rovina lowland in 2009 and 2010

Republic)]. Státní zemědělské nakladatelství, Praha, Tomé R, Catry P, Bloise C & Korpimäki E 2008: Breeding 180 [In Czech] density and success, and diet composition of little Schönn S, Scherzinger W, Exo K-M & Ille R 1991: Der owls Athene noctua in steppe-like habitats in Portugal. Steinkauz. Die neue Brehm-Bücherei 606. Wittenberg Ornis Fennica 85: 22–32. Lutherstadt, Ziemsen, 237. Townsend RC, Begon M & Harper LJ 2008: Základy eko- Šálek M & Schröpfer L 2008. Population decline of the logie [Essentials of Ecology]. Univerzita Palackého little owl (Athene noctua Scop.) in the Czech Republic. v Olomouci, 518. [In Czech] Polish Journal of Ecology 56(3): 527–534. ÚGKK SR (Úrad geodézie, kartografie a katastra Sloven- Šnírer L, Dubravský A & Harvančík S 2009: Monitoring skej republiky) 2010: Retrieved April 4, 2010, from kuvika obyčajného (Athene noctua) v Nitrianskej pa- http://www.katasterportal.sk. horkatine [Monitoring of Athene noctua in „Nitrianska Veľký J (ed.) 1980: Encyklopédia Slovenska, IV. zväzok pahorkatina“ Hilly Area]. Dravce a sovy 5(2): 20–21. N–Q [The Encyclopedia of Slovakia, IV. Volume [In Slovak with English summary] N-Q]. Veda, Bratislava, 595. [In Slovak] Šťastný K, Randík A & Hudec K 1987. Atlas hnízdního Závalský O 2004: Naši dravci a sovy a jejich praktická rozšíření ptáků v ČSSR 1973/1977 [The atlas of breed- ochrana, Metodika ČSOP č. 29 [Our birds of prey and ing birds of ČSSR 1973/1977]. Academia, Praha, 484. owls and their protection, methodology of ČSOP nr. [In Czech and Slovak] 29]. ZO ČSOP Nový Jičín, 80. [In Czech]

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