NORTH-WESTERN JOURNAL OF ZOOLOGY 12 (1): 14-21 ©NwjZ, Oradea, Romania, 2016 Article No.: e151603 http://biozoojournals.ro/nwjz/index.html

Habitat preferences of Picidae in the agricultural landscape of SE Poland: Is the Syrian syriacus colonizing a vacant ecological niche?

Jerzy MICHALCZUK* and Monika MICHALCZUK

Department of Agrobiology and Environmental Protection, University of Rzeszów, Zelwerowicza 4, 35-601 Rzeszów, Poland *Corresponding author, J. Michalczuk, E-mail: [email protected]

Received: 17. November 2014 / Accepted: 19. April 2015 / Available online: 07. April 2016 / Printed: June 2016

Abstract. In 2007 - 2009, we assessed the degree of colonization by woodpeckers in woods and trees of anthropogenic origin in the agricultural landscape of SE Poland. In order to determine the territorial boundaries of the (in an area of 305 km2), we used the mapping method combined with voice stimulation. The dominated in forests, present in 93% of territories found there, whereas the Syrian Woodpecker dominated in anthropogenic tree stands, occupying 90% of these territories. This species reached a density of 8.63 - 10.55 breeding pairs/10 km2 in anthropogenic tree stands. Low numbers of Great Spotted Woodpeckers also nest in this habitat. Densities of these species were 0.72 - 1.68 breeding pairs per 10 km2 of anthropogenic tree stands. Orchards made up the greatest proportion of Syrian Woodpecker territories at 53.5% and were the only type of tree stand preferred by this species. Parks made up a significant proportion (19.4%) of territories occupied by the Great Spotted Woodpecker, which were clearly favored only by this species. The habitat niches of these two species of woodpeckers overlap. The Syrian Woodpecker does not fully penetrate the available ecological niche of anthropogenic habitats, but compared to forest habitats, where the Great Spotted Woodpecker dominates, it encounters less competition there from native woodpecker species. As its primary competitor, this species is a potential biological barrier inhibiting the Syrian Woodpecker’s colonization of forests in areas of the sympatric occurrence of these two species. Therefore, anthropogenic tree stands are the main gateways and corridors of Syrian Woodpecker expansion in Europe.

Key words: Picidae, Syrian Woodpecker, Great Spotted Woodpecker, habitat preferences, rural landscape.

Introduction Michalczuk 2011, Ciach & Fröhlich 2013, Fröhlich & Ciach 2013, Michalczuk & Michalczuk 2015). It Since the end of the 19th century, the Syrian uses these areas throughout the year, avoiding Woodpecker has colonized much of Europe dense forests, which it inhabits sporadically (BirdLife International 2004). It expanded in the (Winkler 1971, Cramp 1985, Michalczuk & south-eastern part of the continent (Cramp 1985, Michalczuk 2011). When colonizing new areas, Munteanu & Samwald 1997, Zavialov et al. 2008, this is probably done to avoid habitat competition Michalczuk 2014), and has also reached Poland with native woodpecker species, including the (Tomiałojć & Stawarczyk 2003, Michalczuk 2014). most common and most sociobiologically similar Although originally a thermophilic species Great Spotted Woodpecker Dendrocopos major inhabiting the forest communities of Asia Minor (Winkler 1971, Glutz von Blotzheim & Bauer 1980, (Winkler 1973, Glutz von Blotzheim & Bauer Cramp 1985). Great Spotted Woodpecker and 1980), the area of favourable habitat for the Syrian Syrian Woodpecker are also related genetically as Woodpecker has increased recently due to the they can hybridize (Kroneisl-Ruckner 1957, Skakuj establishment of various types of anthropogenic & Stawarczyk 1994, Michalczuk & Michalczuk tree stands, mainly orchards and other woodlots 2006b, Dudzik & Polakowski 2011, Michalczuk et planted near housing estates (Mendelssohn & al. 2014). The Great Spotted Woodpecker species is Yom-Tov 1999, Hatzofe & Yom-Tov 2002, Al- also very ecologically flexible and inhabits a Safadi 2004, Aghanajafizadeh et al. 2011). This variety of forested areas in Europe and Asia, as species also colonizes tree stands inside human well as different types of tree cover in the environment in Europe: parks, orchards, alleys agricultural landscape and cities (Cramp 1985, and gardens, and its nests have even been Mazgajski 1998, Salvati et al. 2001, Tomiałojć & detected in singly growing trees (Szlivka 1957, Stawarczyk 2003, Myczko et al. 2014), where it can 1962, Ruge 1969, Cramp 1985, Michalczuk & breed in sympatry with Syrian Woodpecker end Habitat preference of woodpeckers in rural landscape 15 even hybridize (see works above). next point where stimulation was continued (Michalczuk The study assessed the degree to which the & Michalczuk 2006a, 2006b). The same territory search Syrian Woodpecker has become part of the species method was used for Great Spotted Woodpeckers, which also actively responded to the voice stimulation of the assemblage of native woodpeckers inhabiting the Syrian Woodpecker. The sites where birds were found agricultural landscape of SE Poland. To do this, were noted on a 1:25 000 or 1:10 000 scale topographic we determined the extent of Syrian Woodpecker map. The sex of the birds and their individual plumage and Great Spotted Woodpecker in anthropogenic characteristics were registered, as well as direction from forests and tree stands, and identified their habitat which the flew. In distinguishing neighboring preferences. Since native woodpeckers are territories, important information was gained when primary competitors, they serve as a biological simultaneously identifying individuals from neighboring pairs. In the case of both these species, at least one barrier in expansion of Syrian Woodpecker. additional confirmation of pair sighting, or alternating

male and female, was required. One case of mixed pair of the Great Spotted Woodpecker’s male and Syrian Material and methods Woodpecker’s female was included only for comparison of both these species habitat preferences in forest and Study area anthropogenic tree stands (see method below) as Syrian The study was conducted in south-eastern Poland, close Woodpecker site. Breeding sites were also located on the to Tomaszów Lubelski (50o28'N, 23o40'E, Fig. 1). This area basis of detected nests (average nest detection about 50%, (approx. 305 km2) is characterized by undulating hills of e.g. Michalczuk et al. 2011). Over six controls in each year 195-263 m above sea level (Kondracki 2000). The of the study area from March to July were taken to enable agricultural landscape dominates, comprised an accurate demarcation of the birds’ territories. predominantly of crops (71%) and meadows (11%), Territorial boundaries were determined by connecting the whereas small forests represent only 4% of the area. These maximally distant points where the birds of a given are mostly made up of hornbeam complexes, with a breeding pair were observed. After counting the birds, we substantial share of Common Hornbeam Carpinus betulus calculated the density of breeding pairs of each species and Oak Quercus sp., and conifer stands with a for the total surface area of the study area, as well as for predominance of Scots Pine Pinus sylvestris. The the area of anthropogenic tree cover (Table 1). anthropogenic tree stands accompanying build up areas preferred by the Syrian Woodpecker (Cramp 1985, Assessment of woodpecker habitat preferences Michalczuk & Michalczuk 2011, Michalczuk & To determine the degree of using anthropogenic tree Michalczuk 2015), comprise approximately 14% of the cover and forests by the closely related species of Syrian area (ca. 41.7 km2). They consist mainly of single trees, Woodpecker and Great Spotted Woodpecker, an area alleys, rows of trees and parks, and are dominated by designated as “PL” was distinguished within the study Willow Salix sp., Poplar Populus sp., Maple Acer sp. and area. 157 km2 in size, it was located in the northern part of Ash Fraxinus sp. Apples Malus domestica, Cherries Prunus the study area (Fig. 1). In addition to anthropogenic tree cerasus, Plums Prunus sp., and Walnuts Juglans regia are cover, it included 6 forested sites with a total area of 380 the main species of orchards. Rarely are conifers, such as ha (Fig. 1). The size of individual forests varied from 11 to Spruce Picea sp., Larch Larix sp. or Pine Pinus sp., found in 164 ha (mean of 63.2 ha; 1SD: 55.2, N = 6). The main the anthropogenic tree cover. objective of the 2007 counts conducted in forest area "PL" was solely to assess the number of Syrian Woodpecker Assessment of the number of woodpeckers and Great Spotted Woodpecker territories occupied by The search for woodpeckers was conducted by the pairs or single individuals without determining their mapping method with the use of voice stimulation breeding status. This made it possible to assess the scale (Michalczuk & Michalczuk 2006a, 2006b). The search was of anthropogenic tree cover use and forest use by these carried out mainly in anthropogenic afforestations (41.7 quite sociobiologically similar species (Winkler 1971, km2), as well as in forests adjacent to residential 1973, Glutz von Blotzheim & Bauer 1980). To this end, buildings, where the Great Spotted Woodpecker is most two counts were conducted in all types of tree cover in often found, but these habitats can also be occupied by the entire "PL" area during the pre-breeding period the Syrian Woodpecker (Glutz von Blotzheim & Bauer (March-April). The methodology of searching for 1980, Cramp 1985, Kurek 1984). woodpecker territories was similar to the previously In each seasons 2007-2009, over six field controls were described and based on the recommendation of conducted in whole entire study area. Counting was combining the cartographic method with voice carried out mainly along roads, with voice stimulation stimulation (Michalczuk & Michalczuk 2006a, 2006b). and listening for birds performed at 200-400 m intervals. Voice stimulation was conducted in forested areas in a The voice stimulation consisted of a five minute sequence grid of points, spaced approx. 200-400 m. Voice of Syrian Woodpecker calls and drumming. The stimulation of five minutes duration was performed with stimulation was immediately discontinued when a one minute of listening at each point. The location of a woodpecker reacted. In the absence of a reaction, we bird was recorded on a 1:5 000 scale map, and then we listened for about one minute, and then moved on to the moved to the next point, where the search continued.

16 J. Michalczuk & M. Michalczuk

Figure 1. Distribution of breeding sites of Picidae woodpeckers in the study area in 2007 - 2009. Key: 1 - areas of dense residential buildings, 2 - forests dominated by the Great Spotted Woodpecker D. major, 3 - main roads, 4 - fields and meadows, A - boundaries of the study area, B - boundaries of the “PL” supplemental area, breeding sites: ○ – Syrian Woodpecker, ■ – Great Spotted Woodpecker.

Table 1. Habitat preferences of woodpeckers in relation to different types of anthropogenic trees stands in the agricultural landscape of SE Poland. Key: p.t. – proportion of trees, s.i. – selection index.

Available trees Syrian Woodpecker Great Spotted Woodpecker tree stand n=323 p.t. n=657 p.t. s.i. (95%CL) n=366 p.t. s.i. (95%CL) cemetery 2 0.006 3 0.005 0.74 (0.00-2.68) 5 0.014 2.21 (0.71-3.70) tree clump 82 0.254 64 0.097 0.38 (0.00-0.78) 112 0.306 1.21 (0.94-1.47) park 4 0.012 14 0.021 1.72 (0.83-2.61) 78 0.213 17.21 (16.87-17.54) singly tree 10 0.031 27 0.041 1.33 (0.69-1.96) 8 0.022 0.71 (0.00-1.88) orchard 121 0.375 350 0.533 1.42 (1.30-1.55) 96 0.262 0.70 (0.40-1.00) tree row and alley 104 0.322 199 0.303 0.94 (0.74-1.14) 67 0.183 0.57 (0.20-0.94)

After the counts, we calculated the number of territories tree and orchard. Only sites with trees having a diameter occupied by the woodpeckers in forests and of greater than 15 cm, measured 1.3 m from ground level anthropogenic tree cover. were assessed, as trees of such dimensions are used for During the study, we also assessed the type of tree the excavation of nest holes by woodpeckers, such as, for cover in anthropogenic habitats used by the Great example, the Syrian Woodpecker (own observation). In Spotted Woodpecker and Syrian Woodpecker. To this this way, 20 to 45 tree assessment points were randomly end, we randomly selected points from which the tree selected in specific territories and used to calculate the stands were assessed in all the territories of the Greater proportion of specific types of tree cover within each Spotted Woodpecker (N = 15) and in 28 randomly territory of the birds. In this manner, 366 tree assessment selected territories of the Syrian Woodpecker. In order to points were described for the Great Spotted Woodpecker determine the size of specific territories, maps were used and 657 points for the Syrian Woodpecker (Table 1). at a scale of 1:5 000. On each territory map 100 points The randomly selected points were also used to were randomly selected, and then each was located in the identify the habitat preferences of the woodpeckers. To study area. In a lot of the points there were treeless this end, the share of individual types of tree cover habitats like fields and meadows. When a tree was found located within all the territories of the various at a designated point, it was categorized by type of stand: woodpecker species were compared to their availability alley or row of trees, cemetery, tree clump, park, single in the study area. An assessment of anthropogenic tree Habitat preference of woodpeckers in rural landscape 17 cover in the study site was performed using the same km2 of anthropogenic tree stands), the density of method. To do this, the study area was traced on 45 maps breeding pairs ranged from 8.63 to 10.55/10 km2. scaled at 1:10 000, each covering an area of approximately The Syrian Woodpecker dominated among 10 km2 (4.0 to 2.5 km). On each map 100 points were woodpecker species in anthropogenic tree stands, randomly selected, which were then located in the field. When trees with diameter of >15 cm were observed at where it represented approximately 89% (range in these points, they were assigned to the aforementioned each year’s 86 - 91%) of the breeding population of categories of tree stands. In this way, the types of tree all nesting woodpecker species found. In specific stands were identified for 323 points, which allowed us to sites, most often 1 - 2 breeding pairs of this species determine the proportions of specific types of tree stands were confirmed, and only exceptionally were up in the study area. To assess the habitat preferences of to 4 breeding pairs detected in the largest villages. woodpeckers to particular types of tree stand, we used However, there were also sites where no breeding individual selection indices (Manly et al. 1993). This is the quotable of the share of each type of tree stand found in birds were confirmed (Fig. 1). Each season, the the territories of the birds divided by their proportion in Great Spotted Woodpecker was also noted at 4, 7 the study area. Based on the Bonferroni inequality for and 4 locations. The average density of breeding individual selection indices, 95% simultaneous confidence sites ranged from 0.13 to 0.23 pairs /10 km2 of limits (95% CL) were constructed. If the resulting study area and 0.96 - 1.68 pairs/10 km2 of confidence interval was greater than 1, this meant that the anthropogenic tree stands. The proportion of this type of stand was preferred. When it was less than 1, this species in the breeding assemblage of indicated that the woodpeckers avoided this particular type of tree stand. Confidence intervals of individual woodpeckers averaged 11%. selection indices with a value of 1 meant the lack of woodpecker preference to the tree stand category. The habitat preferences of woodpeckers Negative lower limits of the confidence intervals were During the census conducted in 2007 of the "PL" changed to 0.00, as negative values of the confidence area, clear differences were found in the habitat intervals are not possible. preferences of both species of woodpeckers (χ2 = The chi-square test, Mann Whitney U test and 46.02, df = 1, p < 0.0001, Fig. 2). The Syrian Kruskall-Wallis test with the Dunn post-hoc test were used for the statistical analysis, which was performed Woodpecker dominated in the anthropogenic tree using Excel and the StatisticaSoft 7.1 GB package. stands, with 35 territories (90% of territories). The Statistical differences were accepted at a significance level Great Spotted Woodpecker had only 4 territories equal to or lower than 0.05. We also calculated the width in this habitat, mostly located near parks. The of the habitat niches occupied by each species (Levins proportion of the occurrence of both these species 1968). For this, we used the following formula: in forests was the opposite. This is where the B= 1 , Great Spotted Woodpecker dominated, occupying 2  pi 27 territories (93% of territories). The Syrian where: Woodpecker clearly avoided forests, as it was B – index of the habitat niche width, p – share of „i” in the habitat niche. To calculate the degree of niche overlap between the habitats of the species, Schoener's index (1968) was used:

OI=1-1/2∑(pxi-pyi),

where pxi and pyi represent the frequency of tree cover category „i” in the territories of specific species of woodpeckers x and y. OI is the variable from 0 (no overlap) to 1 (complete coverage), and niche overlap is accepted as significant if the value of the index exceeds 0.60 (Wallace 1981).

Results

Distribution and number of woodpeckers In 2007 - 2009, the population Syrian Woodpeckers was estimated respectively at 44, 42 and 36 pairs. Figure 2. Habitat preferences of the Syrian Woodpecker Its density ranged from 1.18 to 1.44 breeding pairs (white area) and Great Spotted Woodpecker (grey area) 2 per 10 km of study area. Taking into account only in the “PL” supplemental area in 2007. The values over the area of optimal habitat for this species (41.7 the columns represent the number of noted territories.

18 J. Michalczuk & M. Michalczuk

Figure 3. Average percentage of specific types of tree stands in Syrian Woodpecker (grey, N = 28) and Great Spotted Woodpecker (white, N = 15) territories located in anthropogenic tree stands (vertical lines – standard errors, * - p < 0.005, ** - p < 0.0005).

confirmed here on only two territories (Fig. 2). In stands, they were used according to their one case it was a mixed pair of the Great Spotted availability in the study area (Table 1). Single trees Woodpecker’s male and Syrian Woodpecker’s represented only 1.6% (1SD: 3.0), and cemeteries female. 1.3% (1SD: 3.0, Fig. 3) of tree stand types with The proportion of specific tree stand types in Great Spotted Woodpecker territories. The Syrian Woodpecker territories was diverse (H = differences among the share of particular tree 129.32, df = 5, p < 0.0001, Fig. 3). Orchards were stand categories of Great Spotted Woodpecker most frequently reported (mean 53.5%, 1SD: 16.1), territories was statistically significant (H = 44.99, as well as alleys and rows of trees (mean 30.1%, df = 5, p < 0.0001, Fig. 3). The categories of parks, 1SD: 9.6), but the difference in the share of these clumps of trees and orchards were reported categories was not found to be statistically significantly more often than cemeteries (post hoc significant. Both of these types of tree stands, Dunn's test p = 0.0370), while clumps of trees and however, occurred significantly more often than orchards were noted more frequently than single other categories (Dunn's test p < 0.0001 trees (post hoc Dunn's test p < 0.0001). respectively for all categories). Clumps of trees, Tree clumps (Mann Whitney U test Z = -3.87, which accounted for 10.0% (1SD: 10.3), were p = 0.0001) and parks (Mann Whitney U test Z = - avoided by the birds. Only orchards were 2.90, p = 0.0037) were significantly more often preferred by the Syrian Woodpecker (Table 1). represented in the territories of the Great Spotted Alleys and tree rows, parks (mean 1.9%, 1SD 5.1), Woodpecker than in Syrian Woodpecker cemeteries (mean 0.4%, 1SD: 1.3) and single trees territories. Alleys and tree rows (Mann Whitney U (mean 4.2%, 1SD: 4.5) were used by the species test Z = 2.93, p = 0.0034) as well as orchards (Mann according to their availability in the study area Whitney U test Z = 3.50, p = 0.0005) are (Table 1). significantly more often noted as the sites of Alleys and tree rows, however, were avoided Syrian Woodpecker territories. The Great Spotted by the Great Spotted Woodpecker (Table 1), and Woodpecker used a broader range of habitat an average share in its territories of 18.3% (1SD: niches (B = 4.02) than the Syrian Woodpecker (B = 12.2, Fig. 3). The Great Spotted also avoided 2.50). The Syrian Woodpecker’s habitat niche orchards, which accounted for an average of 28.0% overlapped with that of the Great Spotted (1SD: 22.1, Fig. 3). This species preferred only Woodpecker (OI = 0.70) parks, which accounted for 19.4% of the territories (1SD: 18.5, Fig. 3). Clumps of trees were significantly represented among the territories of Discussion the Great Spotted Woodpecker (mean 31.3%, 1SD: The density of Syrian Woodpecker breeding pairs 16.4). However, as with other categories of tree in the agricultural landscape of the study area was Habitat preference of woodpeckers in rural landscape 19 at levels characteristic of south-eastern Poland. In ecological niche devoid of other woodpecker the area of Tomaszów Lubelski, this species species. However, this was not confirmed in reaches a density ranging from 0.8 to 2.1 breeding studies conducted in south-eastern Poland. While pairs per 10 km2 (Michalczuk & Michalczuk 2006a, the Syrian Woodpecker clearly dominated in the Michalczuk et al. 2011, Michalczuk & Michalczuk agricultural landscape, and its abundance was ten 2015). Similar findings were reported in the times higher than that of the Great Spotted municipality of Żurwica (near Przemyśl), where a Woodpecker, the presence of this species in density of 1.6 - 2.1 pairs/10 km2 was noted. anthropogenic habitats unequivocally indicates However, when calculated for the area of optimal that colonizing new areas the Syrian Woodpecker habitat for this species (the tree stands found in penetrates only a partially vacant ecological niche. rural villages), it reached a range of 14.8 - 19.5 Such conclusions can be drawn by analyzing data pairs/10 km2 (Hordowski 1998). The Syrian from the former Vojvodina and Austria, where in Woodpecker density in optimal habitats of the addition to the Syrian Woodpecker, the Great study area was close to the lower range of Spotted Woodpecker also had territories in densities for the agricultural landscape of this part anthropogenic tree stands (Szlivka 1957, Ruge in of Poland (range of 5.5 - 20.0 pairs/km2, 1969, Winkler 1973). This fact is also confirmed by Michalczuk & Michalczuk 2006a, Michalczuk et al. observations from central Ukraine, where until 2011, Michalczuk & Michalczuk 2015), and reflect recently, tree stands in human settlements were a drop in the Syrian Woodpecker population of used quite extensively by the Great Spotted the Tomaszów Lubelski area in recent years Woodpecker. After colonization of these areas by (Michalczuk et al. 2011, Michalczuk & Michalczuk the Syrian Woodpecker, the Great Spotted 2015). Woodpecker retreated to the densest tree stands in The density of the Great Spotted Woodpecker river valleys, parks and woodlots (Mitjaj 1986). obtained during the study confirms their sporadic Such a dependence was also seen in the study nesting in anthropogenic habitats (Cramp 1985, area, where forests were dominated by the Great Tomiałojć & Stawarczyk 2003, Kujawa 2006). Spotted Woodpecker, considered the main Although locally, i.e. in small parks or other dense competitor of the studied species, since both are tree stands in the agricultural landscape, characterized by a similar ecology and biology woodpeckers can reach densities similar to those (Winkler 1971, Glutz von Blotzheim & Bauer 1980, found in forests (Bednorz et al. 2000, Tomiałojć & Cramp 1985) and can form mixed pairs, which Stawarczyk 2003, Kosiński & Kempa 2007, was found in the study area and in other places in Tryjanowski et al. 2009), their concentrations in Poland (Dudzik & Polakowski 2011). Taking into large areas of the agricultural landscape with a account the fact that the both species can hybridize low proportion of forests are smaller. For example, (Kroneisl-Ruckner 1957, Skakuj & Stawarczyk in the agricultural landscape of Wielkopolska 1994, Michalczuk & Michalczuk 2006b, Dudzik & (near Turew in W Poland), the density of the Great Polakowski 2011, Michalczuk et al. 2014), it is Spotted Woodpecker was estimated at 2.0 uncertain which and how many individuals are pairs/10 km2 (Kujawa 1994). These values are genotypically “pure” (e.g. Michalczuk et al. 2014). higher than results obtained in this study. Similar social behaviors (Winkler 1971, 1972) Probably it’s a result of four times higher (15%) result in the Syrian Woodpecker’s general forests share in the study area near Turew, than in avoidance of forests when colonizing new areas the studied area in SE Poland (about 4%). because it is not able to overcome the barrier of the However, it can’t exclude that so high density of equally ecologically flexible Great Spotted Great Spotted Woodpeckers in allopatric Woodpecker. The greater diversity of woodpecker population may come from absence of Syrian species composition and their greater densities in Woodpeckers in the North-West part of Poland forests compared to anthropogenic habitats (Michalczuk 2014). The absence of the Syrian (Bednorz et al. 2000, Tomiałojć & Stawarczyk 2003, Woodpecker as main competitor enable Great Kosiński & Kempa 2007) probably has a Spotted Woodpecker to inhabit spread significant impact on directing the Syrian anthropogenic afforestations in North-West part Woodpecker’s colonization to tree stands in the of Poland. immediate environment of humans, as these are Some authors (eg. Fröhlich & Ciach 2013) usually avoided by woodpeckers. suggest that the Syrian Woodpecker inhabits an Studies have shown that both closely related

20 J. Michalczuk & M. Michalczuk woodpecker species also largely avoided each BirdLife International. (2004): Birds in Europe: population estimates, trends and conservation status. BirdLife International, other within anthropogenic habitats. Although the Conservation Series No. 12. Cambridge. habitat niches of these two species overlap, this Ciach, M., Fröhlich, A. (2013): Habitat preferences of the Syrian study clearly indicated a clear division of site use Woodpecker Dendrocopos syriacus in urban environments: an ambiguous effect of pollution. Bird Study 60: 491-499. between the two species in areas of their Cramp, S. (ed.). (1985): The Birds of the Western Palearctic. 4. sympatric occurrence. Great Spotted Woodpeckers Oxford University Press. Oxford. had territories in the densest tree stand categories, Dudzik, K., Polakowski, M. (2011): [The cases of mixed broods and identification of Syrian Woodpecker Dendrocopos syriacus and Great such as in parks and tree clumps, often inhabited Spotted Woodpecker Dendrocopos major hybrids in Poland]. by this species in the agricultural landscape Chrońmy Przyrodę Ojczystą 67: 254-260. [in Polish] (Tomiałojć & Stawarczyk 2003, Tryjanowski et al. Fröhlich, A., Ciach, M. (2013): [Distribution and abundance of the Syrian Woodpecker Dendrocopos syriacus in Kraków]. Ornis 2009). Orchards clearly dominated as the Polonica 54:237-246. [in Polish] territories of Syrian Woodpeckers, which are often Glutz von Blotzheim, U.N., Bauer, K. (eds). (1980): Handbuch der readily chosen by them (Szlivka 1957, 1962, Ruge Vögel Mitteleuropas. 9. Akademische Verlag, Wiesbaden. Gorman, G. (2004): Woodpecker nest holes. Alula 3: 122-125. 1969, Michalczuk et al. 2011, Michalczuk & Hatzofe, O., Yom-Tov, Y. (2002): Global warming and recent Michalczuk 2015). Preference for orchards may be changes in Israel’a avifauna. Israel Journal of Zoology 48: 351- related to the nutritional requirements of the 357. Hordowski, J. (1998): [The atlas of breeding birds in the municipality of Syrian Woodpecker. This species widely forages Żurawica (agricultural landscape)]. Badania ornitologiczne Ziemi on fruits and seeds, and is the only European Przemyskiej 6: 7-90. [in Polish] woodpecker to feed these items to their chicks Koenig, W.D. (2003): European Starlings and their effect on native cavity-nesting birds. - Conservation Biology 17: 1134-1140. (Cramp 1985). It also often produces nest holes in Kondracki, J. (2000): [Regional geography of Poland]. PWN, fruit trees (Szlivka 1957, 1962, Ruge 1969, Cramp Warszawa, pp. 450. [in Polish] 1985), which grow mainly in orchards found in Kosiński, Z., Kempa, M. (2007): Density, distribution and nest-sites of woodpeckers Picidae, in a managed forest of Western Poland. close proximity to humans. The study area’s Polish Journal of Ecology 53: 519-533. anthropogenic tree stands were also inhabited by Kroneisl-Ruckner, R. (1957): Der Blutspecht, Dendrocopos syriacus, in other potential competitors of the Syrian Kroatien und die Frage seiner Bastardierung mit dem Buntspecht, Dendrocopos major. Larus 9/10: 34-47. Woodpecker, such as the Wryneck (own Kujawa, K. (1994): [Breeding avifauna of Dezydery Chłapowski observation). Other species also readily use nest Agroecolgy Landscape Park]. Biuletyn Parków Krajobrazowych. holes after the Syrian Woodpecker, such as the Agroekologicznego PK i Przemęckiego PK. 1: 37-49. [in Polish] Kujawa, K. (2006): [Effect of afforestations and agricultural landscape Starling Sturnus vulgaris (Szlivka 1957, 1962, structure on breeding bird communities in afforestations]. Rozprawy Michalczuk et al. 2011). This common secondary Naukowa AR im. A. Cieszkowskiego 381, Poznań. [in Polish] hole nester can vigorously compete for tree holes Kurek, H. (1984): [Syrian Woodpecker in the San Valley]. Notatki Ornitologiczne 25: 65-68. [in Polish] with primary hole nesters (e.g. Koenig 2003, Levins, R. (1968): Changing Environments. Monographs in Wiebe 2003), including the Syrian Woodpecker Population Ecology. 2nd Ed. Princeton University Press. (Szlivka 1957, 1962, Michalczuk et al. 2011, Princeton. New Jersey. Manly, B., McDonald, L., Thomas, D. (1993): Resource Selection by Michalczuk & Michalczuk 2016). However, . Statistical Design and Analysis For Field Studies. anthropogenic tree stands as habitats with less Chapman and Hall. London. competitive pressure from native woodpecker Mazgajski, T.D. (1998): Nest-site characteristic of Great Spotted Woodpecker Dendrocopos major in central Poland. Polish Journal species, especially the closely sociobiologically of Ecology 46: 33-41. related Great Spotted Woodpecker, are the main Mendelssohn, H., Yom-Tov, Y. (1999): A report of birds and gates and corridors of Syrian Woodpecker mammals which have increased their distribution and abundance in Israel due to human activity. Israel Journal of expansion in its colonization of new areas of Zoology 45: 35-47. Europe. Michalczuk, J. (2014): Expansion of the Syrian Woodpecker Dendrocopos syriacus in Europe and Western Asia. Ornis Polonica 55: 149-161. Michalczuk, J., McDevitt, A.D., Mazgajski, T.D., Figarski, T., Ilieva, M., Bujoczek, M., Malczyk, P., Kajtoch, Ł. (2014): Tests of References multiple molecular markers for the identification of Great Spotted and Syrian Woodpeckers and their hybrids. Journal Aghanajafizadeh, A., Heydari, F., Naderi, G., Hemami, M.R. (2011): of Ornithology 155: 591-600. Nesting hole site selection by the Syrian Woodpecker, Michalczuk, J., Michalczuk, M. (2006a): Reaction on playback and Dendrocopos syriacus, in Yazad province, Iran. Zoology in the density estimations of Syrian Woodpecker Dendrocopos syriacus Middle East 53: 3-6. in agricultural areas of SE Poland. Acta Ornithologica 41: 33–39. Al-Safadi, M.M. (2004): On the breeding biology of the Syrian Michalczuk, J., Michalczuk, M. (2006b): [The usefulness of the Woodpecker, Dendrocopos syriacus, in the Gaza Strip. Zoology in mapping method with playback in estimation of the numbers of the the Middle East 32: 7-12. Syrian Woodpecker Dendrocopos syriacus]. Notatki Ornitologiczne Bednorz, J., Kupczyk, M., Kuźniak, S., Winiecki, A. (2000): [The 47: 175-184. [in Polish] Birds of Wielkopolska]. Bogucki Wyd. Nauk., Poznań. [in Polish] Habitat preference of woodpeckers in rural landscape 21

Michalczuk, J., Michalczuk, M. (2011): [Syrian Woodpecker Skakuj, M., Stawarczyk, T. (1994): Die Bestimmung des Blutspechts Dendrocopos syriacus in the Upper Huczwa River Watershed in 2004- Dendrocopos syriacus und seine Ausbreitung in Mitteleuropa. 2006]. Chrońmy Przyrodę Ojczystą 67: 426-432. [in Polish] Limicola 8: 217-241. Michalczuk, J. Michalczuk, M. (2015): [Decline of the Syrian Szlivka, L. (1957): Von der Biologie des Blutspechts Dendrocopos Woodpecker Dendrocopos syriacus population in rural landscape in syriacus balcanicus, und seinen Beziehungen zu den Staren, SE Poland in 2004–2012]. Ornis Polonica 56: 67-75. [in Polish] Sturnus vulgaris. Larus. 9/10: 48-70. Michalczuk, J. Michalczuk, M. (2016): The reproductive biology of Szlivka, L. (1962): Weitere Angaben über den Blutspecht aus der the Syrian Woodpecker Dendrocopos syriacus in a newly näheren Umgebung von Gunaroš. Larus 14: 121-134. colonized area of south-eastern Poland. Journal of Ornithology Tomiałojć, L., Stawarczyk, T. (2003): [The avifauna of Poland. 157: 179-187. Distribution, numbers and trends]. PTPP “pro Natura”. Wrocław. Michalczuk, J., Michalczuk, M., Cymbała, R. (2011): [The usefulness [in Polish] of various methods of monitoring the population size of the Syrian Tryjanowski, P., Kuźniak, S., Kujawa, K., Jerzak, L. (2009): [Ecology Woodpecker Dendrocopos syriacus]. Ornis Polonica 52: 280-287. [in of Birds in Agricultural Landscape] Bogucki Wyd. Nauk., Poznań. Polish] [in Polish] Mitjaj, I.S. (1986): [Syrian Woodpecker in the forest-steppe in Wallace, R.K.Jr. (1981): An assessment of diet-overlap index. Pridneprovsky Land. Birds distribution in SSSR, conservation and Transactions of the American Fisheries Society. 110: 72-76. rational management]. Wyd. Akademija Nauk SSSR, Leningrad, Wiebe, K.L. (2003): Delayed timing as a strategy to avoid nest-site 70-71. [in Russian] competition: testing a model using data from starlings and Munteanu, D., Samwald, O. (1997): Dendrocopos syriacus Syrian flickers. Oikos 100: 291-298. Woodpecker. W: Hagemeijer W.J.M., Blair M.J. The EBCC Atlas Winkler, H. (1971): Die artliche Isolation des Blutspechts Picoides of European Breeding Birds: Their Distribution and Abundance. (Dendrocopos) syriacus. Egretta 14: 1-20. T&A D Poyser. London. Winkler, H. (1972): Beitrege zur Ethologie des Blutspechts Myczko, Ł., Rosin, Z.M., Skórka, P., Tryjanowski, P. (2014): (Dendrocopos syriacus). Das nicht-reproduktive Verhalten. Urbanization Level and Woddland Size Are Major Drivers of Zaitschrift für Tierpsychologie 31: 300-325. Woodpecker Species Richness and Abundance. PloS ONE 9(4): Winkler, H. (1973): Nahrungserwerb und Konkurrenz des e94218. Blutspechts Picoides (Dendrocopos) syriacus. Oecologia 12: 193- Ruge, K. (1969): Beobachtungen am Blutspecht Dendrocopos syriacus 208. im Burgenland. Vogelwelt 90: 201-223. Zavialov, E., Tabachishin, V.G., Mosolova, E.Y. (2008): Expansion of Salvati, L., Manganaro, A., Ranazzi, L. (2001): Wood occupation Syrian Woodpecker in European Russia and Ukraine. Dutch and area requirement of the Great Spotted Woodpecker Picoides Birding 30: 236-238. major in Rome (Central Italy). Acta Ornithologica 36: 19-23. Shoener, T.W. (1968): The Anolis lizards of Bimini: resource partitioning in a complex fauna. Ecology 49: 704-726.