Population densities of birds breeding in urbanized habitats in the Grabiszyn district in the city of Wrocław

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1 ISSN Acta Mus. Siles. Sci. Natur., 63: , 2014 DOI: /cszma Population densities of birds breeding in urbanized habitats in the Grabiszyn district in the city of Wrocław Grzegorz K o p i j Population densities of birds breeding in urbanized habitats in the Grabiszyn district in the city of Wrocław. Acta Mus. Siles. Sci. Natur., 63: , Abstract: Studies were carried out in 2010 by mean of simplified version of the mapping method. The study area (395 ha) was located close to the city centre. It comprised a mosaic of urbanized habitats, with a clear dominance of green areas, such as parks (41.1 ha), gardens, cemeteries and tree clumps. A total of 48 breeding bird species were recorded in the whole study area. The most common (>25 pairs/100 ha) were Passer domesticus, Passer montanus, Sturnus vulgaris, Parus caeruleus, Parus major, Apus apus and Columba livia. Numerous (7-15 pairs/100 ha) were also the following species: Columba palumbus, Turdus pilaris, Sylvia atricapilla, Serinus serinus, Turdus merula and Pica pica. Insectivorous birds were the most common birds constituting 63.3%, and granivorous 32.6% of all pairs recorded. Most birds nested in tree holes (39.3%), in/on buildings (30.2%) and in trees/shrubs (25.6%). Distribution of breeding pairs of 23 bird species was presented on maps. Population trends for 17 species were documented. Rapid increase in numbers of Turdus pilaris, Corvus cornix and Phoenicurus phoenicurus and decrease of Pica pica were recorded. Key words: Turdus merula, Turdus pilaris, Luscinia megarhynchos, Corvus cornix, Pica pica; Lower Silesia, urban ecology, population densities, population trends. Introduction Quantitative studies on avian communities in urban habitats have been subject of intense studies throughout Europe (e.g. Tomiałojc, Stawarczyk 2003; Kalcey, Reinwald 2005; Dunn, Westen 2008). Such studies were usually conducted by means of so called combined or standard mapping method (Tomiałojc 1980; Hustigs et al. 1989, Bibby et al. 1992), being therefore restricted to very small study plots (usually below 30 ha). The potentials of this method have been almost totally run out in Europe. Although few aspects of avian population ecology have been thoroughly investigated by means of these methods (e.g. population densities, dominance structure, population trends), obtained results are reliable only in regard to very common, territorial and usually forest birds (e.g. Paridae, Turdidae, Sylvidae, Sittidae and few other), therefore species that usually have none or, at most, low conservation priority. For less common bird species, especially nonpasserines, such results are not representative, as study plots are too small. These species are, however, of much higher conservation priority than the very common passerines. Quantitative data on these species have, therefore, much higher practical implications than those on common species. Despite this, the data are, however, by far less available than those on common species of least conservation concern. Normally, none or only single pairs of these species are recorded, or only unknown parts of their territory is mapped, if combined or standard method is employed as it is usually practiced (on plots ha in surface size), which make such data useless. Even for many common species, the combined or standard mapping methods provide useless and misleading data. For example the Rook Corvus frugilegus or Starlings Sturnus vulgaris usually nest in large colonies or semi-colonies in urban parks. If breeding bird community is studied in such park, then the Rook or Starling will be uncritically assessed as eudominant species, with very high population density. However, Rooks and Starlings only nested in the park, while their main foraging grounds were located outside it. What matters much here is not the nesting 139

2 territory, but the foraging range. Calculating their densities per surface area of this park doesn t make sense. The same is applicable if population densities for species such as finches (Fringillidae), swallows Hirundidae), Jackdaw Corvus monedula and many others. It is apparent that if population densities of those common and all uncommon species have to be assessed reliably, the study plots must be by far much larger than 30 ha. It is advisable that such plots should be at least ha in size in the urbanized environment of cities and larger towns. Only a simplified version of territory mapping method can be applied in such cases (Bibby et al. 1992). Studies are usually restricted to four counts, and very common species are normally excluded from counting (Luniak et al. 2001, Nowicki 2001). With these important precautions in mind, often neglected by researchers, I have studied less common bird species in a fragment of a larger Polish city. The purpose of this study was to provide reliable data on population densities of selected bird species in urbanized landscape. By doing this, I have also provided a basis for monitoring studies intended to detect population trends in these species. The data are of crucial importance not only for understanding urbanization mechanisms in birds, but also for nature conservation, ecotourism, and for proper urban planning. Study area The study area (395 ha) included Grabiszyn, a district in the city of Wrocław, Lower Silesia. It is located from 700 m to 1200 m from the city hall, and borders to Ślęża River to the west, railway to the east and north, and Racławicka street in the south. The area comprised a mosaic of typical urbanized habitats: residential area, industry area, gardens, cemeteries, parks and other timbered areas, sport fields and wastelands. Parks and cemeteries covered together 73.5 ha. Two places in the study area, Grabiszyński Park and Grabiszyński Cemeteries, are especially important for birds. The former one, 40.1 ha in size, comprises basically a mature Tilio-Carpinetum hornbeam forest modified by man. The trees stand is dominated by species such as the Hornbeam Carpinus betulus, Lime Tilia cordata, Beech Fagus sylvatica, Maple Acer platanoides, Spruce Picea sp., Black Pine Pinus nigra and Thuja sp. The undergrowth is dense in central part and dominated by Sambucus nigra, Padus avium and Hedera helix, with an admixture of Prunus spinosa, Crataegus monogyna and some other species. Grabiszyński Cemetery, 30.6 ha in size, is situated on the right bank of Ślęża River. It was established in To a large extend, the soil is covered with stones, concrete and similar material. Undergrowth is quite dense and dominated by coniferous species: Tuja sp., Chamaecyparis sp., Taxus baccata and young Picea abies, Pinus sylvestris. The tree stand is composed mainly of oaks Quercus robur and maples Acer platanoides. Methods A simplified version of the territory mapping method (Bibby et al. 1992) has been employed. As in other large urbanized plots, e.g. in Berlin (Berliner Ornithologische Berichte), Warsaw (Luniak et al. 2001, Nowicki 2001), Wrocław (Kopij 2005, 2007, 2010) four counts were conducted over the whole study area; each one in the following months: April, May, June and July Five mornings were needed to cover the whole study area during each month count. The following very common species were excluded from counting: Rock Dove Columba livia, Common Swift Apus apus, House Sparrow Passer domesticus, Tree Sparrow Passer montanus, Starling Sturnus vulgaris, Great Tit Parus major, and Blue Tit Parus caeruleus. Their numbers were only roughly estimated. Each occupied territory was assumed as representing one breeding pairs (Bibby et al. 1992). The numbers of breeding pairs of species such as Common Kestrel Falco tinnunculus, Hooded Crow Corvus cornix and Magpie Pica pica were based on counting their occupied nests only. Distribution of breeding pairs of 23 selected species is presented on maps. Occupied territories (= breeding pairs) are indicated with red dots, probably occupied territory (= probably breeding pairs) with yellow dots. 140

3 Results and discussion A total of 48 bird species were recorded as breeding in the study area. The most common species, each one with a density higher than 25 pairs per 100 ha, included: House Sparrow, Starling, Rock Dove, Common Swift, Great Tit, Blue Tit, and Tree Sparrow (Table 1). Altogether they comprised about 2/3 of all breeding birds. Common were also the following other species: Blackbird Turdus merula, Blackcap Sylvia atricapilla, Wood Pigeon Columba palumbus, Chiffchaf Phylloscopus collybita, Chaffinch Fringilla coelebs, Serine Serinus serinus, Magpie, Hooded Crow, Fieldfare Turdus pilaris, and Collared Dove Streptopelia decaocto. In total, 390 pairs of these species were recorded. Each species nested in a density 5-17 pairs per 100 ha. The remaining 118 pairs belonged to 30 remaining species (Table 1). It is interesting to note the presence of typical forest species in the study area, such as: Golden Crest Regulus regulus, Fire Crest Regulus ignicapillus, Wren Troglodytes troglodytes, Jay Garrulus glandarius, and Black Woodpecker Drycopus martius. All of them were recorded in Grabiszyński Park, where fairly old natural hornbeam forest still prevails. The Tawny Owl Strix aluco and the Long-eared Owl Asio otus were also most probably breeding in the study area. However, counts were not conducted in the night and their presence was, therefore, not detected. Most species were clumped in parks, cemeteries and other green areas (Fig. 1-23). Several species were recorded as breeding only in parks and cemeteries. The group included: Song Thrush Turdus philomelos, Pied Flycatcher Ficedula hypoleuca, Golden Crest, Fire Crest, Wren, Great Woodpecker Dendrocopos major, Wood Warbler Phylloscopus sibilatrix, Jay, Grossbeak Coccothraustes coccothraustes, Black Woodpecker, Garden Warbler Sylvia borin, Long-tailed Tit Aegithalos caudatus, and Marsh Tit Parus palustris. Insectivorous birds were most common (63.3% of all pairs [N=1622]; 83.3% of all species [N=48]); much less common were granivorous birds (32.6% pairs; 12.5% species). Most birds nested in tree holes (39.3% of all pairs; 31.3% of all species), in/on buildings (30.2% pairs, 12.5% species) and in trees (25.6% pairs, 35.4% species); much less in low herbaceous vegetation (4.9% pairs, 20.8% species). It should be pointed out that species, such as the Magpie, Hooded Crow and Fieldfare nested in 2010 in relatively high densities in the study area (Table 2), but in the 1970 s, they were not breeding in the area at all (Dyrcz et al. 1991). An increase in the number of the Hooded Crow and a decline in the number of the Magpie and Nightingale Luscinia megarhynchos in the study area in the last 17 years have been documented (Table 2). While the Black Woodpecker and Collared Flycatcher Ficedula albicollis were recorded for the first time in 2010, species such as Stonechat Saxicola torquata, Whinchat Saxicola rubetra and Wheathaer Oenanthe oenanthe, which nested in 1993, were not recorded in 2010 (Table 2). The disappearance of chats from the study area was caused by destruction of their breeding habitats, i.e. wastelands located on the periphery of the study area, now reclaimed for housing estate. References Bibby C.J., Burgess N.D. & Hill D.A. (1992): Bird census techniques. Academic Press, London. Dunn A. M. & Weston M.A. (2008): A review of terrestrial bird atlases of the world and their application. Emu 108: Dyrcz A., Grabiński W., Stawarczyk T. & Witkowski J. (1991): Ptaki Śląska monografia faunistyczna. Uniwersytet Wrocławski, Wrocław. Hustings M.F.H., Kwak R.G.M., Opdam P.F.M. & Reijnen M.J.S.M. (1989): Vogelinventarisatie: achtergronden, richtlijnen en verslaglegging. Pudoc, Wegeningen. Kalcey J.G. & Rheinwald G. (eds) (2005): Birds in European cities. Ginster Verlag, St. Catharinen 141

4 Kopij G. (2005): Ptaki lęgowe zachodniej części Śródmieścia we Wrocławia. Zesz. nauk. AR Wrocław, Ser. Zootechnika 53: (2007): Ptaki lęgowe Starego Miasta we Wrocławiu. Zesz. Nauk. UP Wrocław, Biol. i Hod. Zwierz. 55: (2010): Ptaki lęgowe północno-wschodniej części dzielnicy Fabrycznej we Wrocławiu. Zesz. nauk. UP Wrocław, Biol. i Hod. Zwierz., 60: Luniak M., Kozłowski P., Nowicki W. & Plit J. (2001): Ptaki Warszawy, Instytut Geografii i Przestrzennego Zagospodarowania PAN, Warszawa. Nowicki W. (2001): Ptaki śródmieścia Warszawy. MiIZ PAN, Warszawa. Okólska H. & Burak M. (2007): Cmentarze dawnego Wrocławia. Muzeum Architektury we Wrocławiu, Wrocław. Orłowski G., Martini K. & Martini M. (2002): Liczebność i rozmieszczenie sroki Pica pica w południowozachodniej części Wrocławia. Ptaki Śląska, 14: (2004): Rozmieszczenie i liczebność pleszki Phoenicurus phoenicurus w południowo-zachodniej części Wrocławia. Chr. Przyr. ojcz. 60(5): (2006): Awifauna południowo-zachodniej części Wrocławia. Ptaki Śląska 16: Rachel M., Grzesiak W., Martini K. & Martini M. (2002): Sowy Strigiformes miasta Wrocławia. Ptaki Śląska 14: Tomiałojć L. (1980): Kombinowana odmiana metody kartograficznej do liczenia ptaków lęgowych. Not. Orn. 21: Tomiałojć L. & Stawarczyk T. (2003): Awifauna Polski, Rozmieszczenie, liczebność i zmiany. Pro Natura, Wrocław. Author s address: Grzegorz Kopij, Department of Vertebrate Ecology, Wrocław University of Environmental & Life Sciences, Kożuchowska 5b, Wrocław; grzegorz.kopij@up.wroc.pl 142

5 Appendix: tables and maps Tab 1: Number of breeding pairs of birds in the whole study area (395 ha) in Species Number of pairs Pairs/ 100 ha Passer domesticus Sturnus vulgaris Columba livia Parus major Parus caeruleus Apus apus Passer montanus Turdus merula Sylvia atricapilla Columba palumbus Phylloscopus collybita Fringilla coelebs Pica pica Serinus serinus Corvus cornix Regulus regulus Turdus pilaris Streptopelia decaocto Sitta europaea Phoenicurus ochruros Phoenicurus phoenicurus Sylvia curruca Luscinia megarhynchos Turdus philomelos Acrocephalus palustris Muscicapa striata Ficedula hypoleuca Carduelis carduelis Dendrocopos major Hippolais icterina Oriolus oriolus Phylloscopus sibilatrix Garrulus glandarius Certhia brachydactyla Coccothraustes coccothraustes Sylvia communis Acrocephalus arundinaceus Lanius collurio Regulus ignicapillus Phylloscopus trochilus Dryocopus martius Hirundo rustica Sylvia borin Aegithalos caudatus 1? 0.3 Parus palustris 1? 0.3 Cuculus canorus Picus canus Ficedula albicollis

6 Tab 2: Numbers of breeding pairs of some bird species in 1993 and Species Trend Dryocopus martius 0 1 * Picus viridis 3 2 Picus canus Dendrocopos major 7 5 Dendrocopos medius Dendrocopos minor Asio otus 7? Strix aluco 4? Turdus pilaris 4 22 Pica pica Corvus cornix 5 32 Luscinia megarhynchos Phoenicurus phoenicurus 5 14 Saxicola rubetra 3 0 Saxicola torquata 3 0 Oenanthe oenanthe 4 0 Ficedula albicollis * Data from 1993 are taken from Orłowski et al. 2002, 2004, * - species new to the area, + - species withdrawn from the study area, - stable, - increase, - rapid increase, - decrease, - rapid decrease. Maps 1-23: Distribution maps of the species in the study area. Oriolus oriolus Fringilla coelebs 144

7 Lanius collurio Sylvia communis Turdus merula Turdus pilaris 145

8 Columba palumbus Streptopelia decaocto Certhia brachydactyla Sylvia atricapilla 146

9 Hippolais icterina Pica pica Corvus cornix Muscicapa striata 147

10 Hirundo rustica Phylloscopus collybita Acrocephalus arundinaceus Phoenicurus phoenicurus 148

11 Sylvia curruca Acrocephalus palustris Luscinia megarhynchos Sitta europaea 149

12 EXPLANATIONS TO FIGURES Phoenicurus ochruros Brown area residential area Grey area industrial area Green area parks Blue-green area gardens Purple area cemeteries Whitish area waste land Black line railway Blue line river White roads and streets Red dot breeding pair Yellow dot probably breeding pair 150