The Journal of V. N. Karazin Kharkiv National University, Series "Biology"
Intending to create a regional landscape park, we investigated various sites of upland oak forest... more Intending to create a regional landscape park, we investigated various sites of upland oak forests, pine forests on the above-floodplain terrace of the left bank of the Udy River, adjacent floodplain meadows on both banks, and swampy soil depressions near the village of Ternovaya. In total, we proposed seven segments with a total area of 6173.03 hectares to be included in the Smarahdove Dzherelo Regional Landscape Park, a projected conservation area in the south of the Kharkiv District of the Kharkiv Region. The studied oak forests on the right river bank and flat interfluves, pine forests on the above-flooded terrace, and the Udy floodplain are examples of the typical landscape of Slobidska Ukraine. The Udy floodplain hosts meadows of a significant area and alder forests in humid near-terrace depressions; dry meadows are confined to forest edges and fallow lands. In total, ten endangered natural habitats listes in the Berne Convention are presented in the study area. Flora and ve...
We investigated the properties of the sounds recorded on the territory of the National Park “Homi... more We investigated the properties of the sounds recorded on the territory of the National Park “Homilshanski Lisy” (Kharkiv region, Ukraine). Recordings were made at five points (in mature, middle-aged, and young oak forests, overgrown clear-cut and aspen forests). Data collection was carried out using on-site positioning of AudioMoth autonomous recorders, located on trees at a height of 1.5 m. The recording was made from April 11 to July 10, 2020, for 3 h in the morning and evening with a 5-min duration followed by a 10-min pause (24 recordings per day). Six acoustic indices (AIs) were calculated: Acoustic complexity index (ACI), acoustic diversity index (ADI), acoustic evenness index (AEI), bioacoustic index (BI), normalized difference soundscape index (NDSI), and acoustic entropy index (H). For the analysis, we used the Friedman test as well as a nonparametric analysis of the variance of the distance matrix and Tukey’s test. The results of the analysis showed the statistical signifi...
The biggest Common Crane premigratory gathering in the Kharkov region (North-Eastern Ukraine) was... more The biggest Common Crane premigratory gathering in the Kharkov region (North-Eastern Ukraine) was found as far back as 1981 in the Izyum district. Permanent observation on birds’ movement has been carried out since 1991 in “Izyum luka” woodland. The dynamics and phenology of formation and disintegration of the gathering were investigated. The average number of birds decreased from 150 to 96 during the observation period. The dates of gathering formation shifted from the 1st of August to the mid of August. It is suggested to use the data about first stage of gathering formation for estimating the number of birds breeding on this territory.
Visnyk of Dnipropetrovsk University. Biology, ecology, 2016
This investigation was carried out in a forest on the southern borders of the Central-Russian Upl... more This investigation was carried out in a forest on the southern borders of the Central-Russian Upland, on the Prioskolsky plateau, in the Srednedonskoy subprovince of the Pontic steppe province. The aim of this work is to identify the peculiarities of structure and ways of formation of the breeding population of ravine oak forests on the border of two geographic zones. The objectives of the work were to describe quantitative and qualitative characteristics of the population of the nesting birds of ravine oak forests, as well as provide an analysis of the faunogenesic structure of the nesting bird population. To obtain data on the species composition and density of nesting birds we used the line transect method by D. Hayne – Y. Ravkin. The surveys were carried out in 2011–2015 three times per season (April to June). The indicators of the breeding density of each bird species and the totals for each year were calculated. The Polydominant Simpson index was used to characterize species d...
One of the problems that may arise when conducting long-term monitoring of bird populations in fo... more One of the problems that may arise when conducting long-term monitoring of bird populations in forest landscapes may be discrepancies between data obtained by different researchers. Using acoustic monitoring may solve this problem. To establish the suitability of the acoustic method for monitoring the state of forest ecosystems, studies were conducted in May and June 2018 on seven plots different from each other by stand age and species composition in a maple-linden-oak forest in northeastern Ukraine. The species composition of birds, the structure and composition of the stand and the values of six acoustic indices were calculated. Differences were found in all acoustic indices at different sites. The smallest values of the indices were noted in the overgrown clear-cut. Four acoustic indices in the May survey and five of the six in the June survey show significant correlations with the species richness of birds. All indices correlate with the values of several stand variables, which...
Fire is an important structuring force for grassland ecosystems. Despite increased incidents of f... more Fire is an important structuring force for grassland ecosystems. Despite increased incidents of fire in European steppes, their impact on arthropod communities is still poorly studied. We assessed short-term changes in cursorial beetle and spider assemblages after a summer fire in the meadow steppe in Central European Russia. The responses of spider and beetle assemblages to the fire event were different. In the first post-fire year, the same beetle species dominated burnt and unburnt plots, the alpha-diversity of beetle assemblages was similar, and there were no pronounced changes in the proportions of trophic groups. Beetle species richness and activity density increased in the second post-fire year, while that of the spiders decreased. The spider alpha-diversity was lowest in the first post-fire year, and the main dominants were pioneer species. In the second year, the differences in spider species composition and activity density diminished. The main conclusion of our study is t...
The steppe marmot inhabits a wide range of open dry grasslands in Eurasia. Throughout this vast a... more The steppe marmot inhabits a wide range of open dry grasslands in Eurasia. Throughout this vast area, marmot habitats have undergone major changes due to human activities. Long-term ecological monitoring was conducted in the European steppe marmot settlements (Marmota bobak bobak) in Northeastern Ukraine in 2001-2019. The data obtained were compared with the observations made in M. b. schaganensis settlements in Kazakhstan during the expedition in 2017. The goals of our investigation were (1) to estimate M. bobak ecological plasticity based on general vegetation parameters of its habitats and settlement structure, (2) to relate the population density of the European subspecies to the food base of its habitats, (3) to evaluate the population response of M. b. bobak to the abandonment of cattle grazing, (4) to ascertain new ecological adaptations (if any) to the habitat changes, and (5) to reveal the steppe marmot's status in the plant-herbivore interaction system in the grasslands of Northeastern Ukraine and Northern Kazakhstan. We have found differences in ecological features of M. b. bobak and M. b. schaganensis. The European subspecies was and continues to be a secondary pasture user. The Kazakhstan subspecies can be both secondary and primary users of the Asian dry steppes. Our studies have shown that the habitats of the European steppe marmot worsened dramatically (due to increased herbage height and cover of uneaten plant species together with litter) in comparison with those of the Kazakhstan subspecies. Presence in diverse habitats with a range of vegetation parameters as well as the differences between the settlement structures of M. b. bobak and M. b. schaganensis demonstrate the high ecological plasticity of the steppe marmot at the species level. At the same time, we have not found any new ecological adaptations that would ensure the survival of M. b. bobak settlements in modern conditions of the total cessation of cattle grazing.
One of the problems that may arise when conducting long-term monitoring of bird populations in fo... more One of the problems that may arise when conducting long-term monitoring of bird populations in forest landscapes may be discrepancies between data obtained by different researchers. Using acoustic monitoring may solve this problem. To establish the suitability of the acoustic method for monitoring the state of forest ecosystems, studies were conducted in May and June 2018 on seven plots different from each other by stand age and species composition in a maple-linden-oak forest in northeastern Ukraine. The species composition of birds, the structure and composition of the stand and the values of six acoustic indices were calculated. Differences were found in all acoustic indices at different sites. The smallest values of the indices were noted in the overgrown clear-cut. Four acoustic indices in the May survey and five of the six in the June survey show significant correlations with the species richness of birds. All indices correlate with the values of several stand variables, which characterize the size and species composition of the stand, understorey and field vegetation, the closeness of various vegetation tiers, and with the distance to the edges and the nearest populated areas. The results suggest the possibility of using an acoustic approach to monitoring the bird population and the state of forest ecosystems.
Until 2000, there was no special nationwide survey of Corncrake in Ukraine. In 2000–2002 we carri... more Until 2000, there was no special nationwide survey of Corncrake in Ukraine. In 2000–2002 we carried out such Corncrake inventory. 377 plots were surveyed during the feldwork. The total area of all census plots was 203,754 ha. Tis constitutes about 0.42 % of the total area suitable for breeding Corncrakes in Ukraine. Stratifed selection method was applied to identify the optimum number of plots for each type of habitat and the total number of plots. Census plots were chosen randomly using the vegetation map of Ukraine. Te census was carried out through direct counting of the number of calling males in selected sample plots twice during the breeding season. The total numbers of Corncrake was estimated at about 127,000 males in 2000 and 102,000 males in 2001. Tis is higher than the population size estimated for Ukraine earlier. Obviously, this is not an actual population increase but rather a more precise estimation based on a wholerange inventory in Ukraine, which had never been done before. At the same time, fgures in the literature were based on rough estimations rather than on reliable census data. Floodplain meadows are the most important habitats supporting the largest number of Corncrakes (45–68,000, or 45-54 % of the Ukrainian population). Te highest density was observed in floodplain meadows in the forest zone (about 2-3 calling males/km2 on average, maximum 40 calling males/km2). Although Corncrake population density is usually low in agricultural landscapes, the total population number in this habitat is considerable with accounting for high percentage of agricultural land area in Ukraine. Corncrake population distribution in Ukraine is not random. The key areas are the northern and north-western parts of the forest zone (Volyn, Rivne and Chernihiv regions) where large numbers and high population densities are observed. Tese areas are characterized by conditions favourable for Corncrake: low proportion of arable lands; signifcant proportion of relatively wet and extensively exploited meadows; well-developed system of drainage and irrigation ditches as well as availability of relatively large areas which are irregularly or scarcely used for agriculture.
OTTER. The journal of the International Otter Survival Fund , 2019
In 2018 the first survey of the Eurasian otter (Lutra lutra) within the Chornobyl exclusion zone ... more In 2018 the first survey of the Eurasian otter (Lutra lutra) within the Chornobyl exclusion zone was carried out using so-called "standard methods" (searches for spraints and other signs of otter presence). The Chornobyl exclusion zone is a 2600 km 2 territory in Kyiv region, Northern Ukraine, where since the Chornobyl nuclear disaster in 1986 the human impact on natural ecosystems has been dramatically reduced. Forest landscapes dominate the zone and the area is well drained by rivers of various sizes and drainage canals. The Eurasian otter has been known to inhabit rivers here long before the disaster and was consistently recorded thereafter but no species-focused survey was attempted. We undertook such a survey covering all major otter habitats e.g. rivers, lakes and drainage canals. The survey was done by inspecting both banks at predetermined sites. The proportion of positive sites was taken as a measure of habitat use. Signs of otter presence were found everywhere within the habitats studied. Otters used large (94% of 18 sites inspected) and medium-sized (81% of 27) rivers more than smaller ones (75% of 16) and more than flood-plain lakes (60% of 5). The least favourable habitats were drainage canals (44% of 52). The habitat distribution of otters in the Chornobyl exclusion zone corresponds well to the data for adjacent territories in Belarus and Ukraine obtained by tracking surveys in winter. This helps to produce a rough estimate of the number of Eurasian otters within the Chornobyl exclusion zone (72-153 individuals).
The valley of Orel’ river, a left bank tributary of Dnieper river, is an important breeding groun... more The valley of Orel’ river, a left bank tributary of Dnieper river, is an important breeding ground for waterfowl and waterbirds in the continental part of Ukraine. The composition and structure of waterfowl and waterbirds communities in Orel’ valley was estimated by the data of counts of breeding pairs and broods on 48 plots in 2005–2017 years. The changes of composition and structure of the communities were revealed by comparison with literature data for the periods of 1910–1920s and 1970–1980s. According to the counts data Coot (Fulica atra) (mean breeding density is 36,2 pairs/km2), Black-headed Gull (Larus ridibundus) (17,3), Black Tern (Chlidonias niger) (11,7), Great Egret (Egretta alba) (6,7), Mallard (Anas platyrhynchos) (4,5), Black-winged Stilt (Himantopus himantopus) (4,5), and Common Pochard (Aythya ferina) (4,3) are the most numerous species. The diversity of breeding species of gulls and terns has grown considerably since early XX century. The numbers of grebes, Greylag Goose (Anser anser), waders and marsh terns have declined for the last three decades. Besides, great colonies of Black-headed Gull and Black-necked Grebe (Podiceps nigricollis) have disappeared. The decline of the majority of species can be partly explained by cumulative negative impact of the fall of water level in lakes and the reduction of grazing pressure around them. However, Orel’ valley retains its important role in supporting populations of Greylag Goose and Common Pochard.
The Journal of V. N. Karazin Kharkiv National University, Series "Biology"
Intending to create a regional landscape park, we investigated various sites of upland oak forest... more Intending to create a regional landscape park, we investigated various sites of upland oak forests, pine forests on the above-floodplain terrace of the left bank of the Udy River, adjacent floodplain meadows on both banks, and swampy soil depressions near the village of Ternovaya. In total, we proposed seven segments with a total area of 6173.03 hectares to be included in the Smarahdove Dzherelo Regional Landscape Park, a projected conservation area in the south of the Kharkiv District of the Kharkiv Region. The studied oak forests on the right river bank and flat interfluves, pine forests on the above-flooded terrace, and the Udy floodplain are examples of the typical landscape of Slobidska Ukraine. The Udy floodplain hosts meadows of a significant area and alder forests in humid near-terrace depressions; dry meadows are confined to forest edges and fallow lands. In total, ten endangered natural habitats listes in the Berne Convention are presented in the study area. Flora and ve...
We investigated the properties of the sounds recorded on the territory of the National Park “Homi... more We investigated the properties of the sounds recorded on the territory of the National Park “Homilshanski Lisy” (Kharkiv region, Ukraine). Recordings were made at five points (in mature, middle-aged, and young oak forests, overgrown clear-cut and aspen forests). Data collection was carried out using on-site positioning of AudioMoth autonomous recorders, located on trees at a height of 1.5 m. The recording was made from April 11 to July 10, 2020, for 3 h in the morning and evening with a 5-min duration followed by a 10-min pause (24 recordings per day). Six acoustic indices (AIs) were calculated: Acoustic complexity index (ACI), acoustic diversity index (ADI), acoustic evenness index (AEI), bioacoustic index (BI), normalized difference soundscape index (NDSI), and acoustic entropy index (H). For the analysis, we used the Friedman test as well as a nonparametric analysis of the variance of the distance matrix and Tukey’s test. The results of the analysis showed the statistical signifi...
The biggest Common Crane premigratory gathering in the Kharkov region (North-Eastern Ukraine) was... more The biggest Common Crane premigratory gathering in the Kharkov region (North-Eastern Ukraine) was found as far back as 1981 in the Izyum district. Permanent observation on birds’ movement has been carried out since 1991 in “Izyum luka” woodland. The dynamics and phenology of formation and disintegration of the gathering were investigated. The average number of birds decreased from 150 to 96 during the observation period. The dates of gathering formation shifted from the 1st of August to the mid of August. It is suggested to use the data about first stage of gathering formation for estimating the number of birds breeding on this territory.
Visnyk of Dnipropetrovsk University. Biology, ecology, 2016
This investigation was carried out in a forest on the southern borders of the Central-Russian Upl... more This investigation was carried out in a forest on the southern borders of the Central-Russian Upland, on the Prioskolsky plateau, in the Srednedonskoy subprovince of the Pontic steppe province. The aim of this work is to identify the peculiarities of structure and ways of formation of the breeding population of ravine oak forests on the border of two geographic zones. The objectives of the work were to describe quantitative and qualitative characteristics of the population of the nesting birds of ravine oak forests, as well as provide an analysis of the faunogenesic structure of the nesting bird population. To obtain data on the species composition and density of nesting birds we used the line transect method by D. Hayne – Y. Ravkin. The surveys were carried out in 2011–2015 three times per season (April to June). The indicators of the breeding density of each bird species and the totals for each year were calculated. The Polydominant Simpson index was used to characterize species d...
One of the problems that may arise when conducting long-term monitoring of bird populations in fo... more One of the problems that may arise when conducting long-term monitoring of bird populations in forest landscapes may be discrepancies between data obtained by different researchers. Using acoustic monitoring may solve this problem. To establish the suitability of the acoustic method for monitoring the state of forest ecosystems, studies were conducted in May and June 2018 on seven plots different from each other by stand age and species composition in a maple-linden-oak forest in northeastern Ukraine. The species composition of birds, the structure and composition of the stand and the values of six acoustic indices were calculated. Differences were found in all acoustic indices at different sites. The smallest values of the indices were noted in the overgrown clear-cut. Four acoustic indices in the May survey and five of the six in the June survey show significant correlations with the species richness of birds. All indices correlate with the values of several stand variables, which...
Fire is an important structuring force for grassland ecosystems. Despite increased incidents of f... more Fire is an important structuring force for grassland ecosystems. Despite increased incidents of fire in European steppes, their impact on arthropod communities is still poorly studied. We assessed short-term changes in cursorial beetle and spider assemblages after a summer fire in the meadow steppe in Central European Russia. The responses of spider and beetle assemblages to the fire event were different. In the first post-fire year, the same beetle species dominated burnt and unburnt plots, the alpha-diversity of beetle assemblages was similar, and there were no pronounced changes in the proportions of trophic groups. Beetle species richness and activity density increased in the second post-fire year, while that of the spiders decreased. The spider alpha-diversity was lowest in the first post-fire year, and the main dominants were pioneer species. In the second year, the differences in spider species composition and activity density diminished. The main conclusion of our study is t...
The steppe marmot inhabits a wide range of open dry grasslands in Eurasia. Throughout this vast a... more The steppe marmot inhabits a wide range of open dry grasslands in Eurasia. Throughout this vast area, marmot habitats have undergone major changes due to human activities. Long-term ecological monitoring was conducted in the European steppe marmot settlements (Marmota bobak bobak) in Northeastern Ukraine in 2001-2019. The data obtained were compared with the observations made in M. b. schaganensis settlements in Kazakhstan during the expedition in 2017. The goals of our investigation were (1) to estimate M. bobak ecological plasticity based on general vegetation parameters of its habitats and settlement structure, (2) to relate the population density of the European subspecies to the food base of its habitats, (3) to evaluate the population response of M. b. bobak to the abandonment of cattle grazing, (4) to ascertain new ecological adaptations (if any) to the habitat changes, and (5) to reveal the steppe marmot's status in the plant-herbivore interaction system in the grasslands of Northeastern Ukraine and Northern Kazakhstan. We have found differences in ecological features of M. b. bobak and M. b. schaganensis. The European subspecies was and continues to be a secondary pasture user. The Kazakhstan subspecies can be both secondary and primary users of the Asian dry steppes. Our studies have shown that the habitats of the European steppe marmot worsened dramatically (due to increased herbage height and cover of uneaten plant species together with litter) in comparison with those of the Kazakhstan subspecies. Presence in diverse habitats with a range of vegetation parameters as well as the differences between the settlement structures of M. b. bobak and M. b. schaganensis demonstrate the high ecological plasticity of the steppe marmot at the species level. At the same time, we have not found any new ecological adaptations that would ensure the survival of M. b. bobak settlements in modern conditions of the total cessation of cattle grazing.
One of the problems that may arise when conducting long-term monitoring of bird populations in fo... more One of the problems that may arise when conducting long-term monitoring of bird populations in forest landscapes may be discrepancies between data obtained by different researchers. Using acoustic monitoring may solve this problem. To establish the suitability of the acoustic method for monitoring the state of forest ecosystems, studies were conducted in May and June 2018 on seven plots different from each other by stand age and species composition in a maple-linden-oak forest in northeastern Ukraine. The species composition of birds, the structure and composition of the stand and the values of six acoustic indices were calculated. Differences were found in all acoustic indices at different sites. The smallest values of the indices were noted in the overgrown clear-cut. Four acoustic indices in the May survey and five of the six in the June survey show significant correlations with the species richness of birds. All indices correlate with the values of several stand variables, which characterize the size and species composition of the stand, understorey and field vegetation, the closeness of various vegetation tiers, and with the distance to the edges and the nearest populated areas. The results suggest the possibility of using an acoustic approach to monitoring the bird population and the state of forest ecosystems.
Until 2000, there was no special nationwide survey of Corncrake in Ukraine. In 2000–2002 we carri... more Until 2000, there was no special nationwide survey of Corncrake in Ukraine. In 2000–2002 we carried out such Corncrake inventory. 377 plots were surveyed during the feldwork. The total area of all census plots was 203,754 ha. Tis constitutes about 0.42 % of the total area suitable for breeding Corncrakes in Ukraine. Stratifed selection method was applied to identify the optimum number of plots for each type of habitat and the total number of plots. Census plots were chosen randomly using the vegetation map of Ukraine. Te census was carried out through direct counting of the number of calling males in selected sample plots twice during the breeding season. The total numbers of Corncrake was estimated at about 127,000 males in 2000 and 102,000 males in 2001. Tis is higher than the population size estimated for Ukraine earlier. Obviously, this is not an actual population increase but rather a more precise estimation based on a wholerange inventory in Ukraine, which had never been done before. At the same time, fgures in the literature were based on rough estimations rather than on reliable census data. Floodplain meadows are the most important habitats supporting the largest number of Corncrakes (45–68,000, or 45-54 % of the Ukrainian population). Te highest density was observed in floodplain meadows in the forest zone (about 2-3 calling males/km2 on average, maximum 40 calling males/km2). Although Corncrake population density is usually low in agricultural landscapes, the total population number in this habitat is considerable with accounting for high percentage of agricultural land area in Ukraine. Corncrake population distribution in Ukraine is not random. The key areas are the northern and north-western parts of the forest zone (Volyn, Rivne and Chernihiv regions) where large numbers and high population densities are observed. Tese areas are characterized by conditions favourable for Corncrake: low proportion of arable lands; signifcant proportion of relatively wet and extensively exploited meadows; well-developed system of drainage and irrigation ditches as well as availability of relatively large areas which are irregularly or scarcely used for agriculture.
OTTER. The journal of the International Otter Survival Fund , 2019
In 2018 the first survey of the Eurasian otter (Lutra lutra) within the Chornobyl exclusion zone ... more In 2018 the first survey of the Eurasian otter (Lutra lutra) within the Chornobyl exclusion zone was carried out using so-called "standard methods" (searches for spraints and other signs of otter presence). The Chornobyl exclusion zone is a 2600 km 2 territory in Kyiv region, Northern Ukraine, where since the Chornobyl nuclear disaster in 1986 the human impact on natural ecosystems has been dramatically reduced. Forest landscapes dominate the zone and the area is well drained by rivers of various sizes and drainage canals. The Eurasian otter has been known to inhabit rivers here long before the disaster and was consistently recorded thereafter but no species-focused survey was attempted. We undertook such a survey covering all major otter habitats e.g. rivers, lakes and drainage canals. The survey was done by inspecting both banks at predetermined sites. The proportion of positive sites was taken as a measure of habitat use. Signs of otter presence were found everywhere within the habitats studied. Otters used large (94% of 18 sites inspected) and medium-sized (81% of 27) rivers more than smaller ones (75% of 16) and more than flood-plain lakes (60% of 5). The least favourable habitats were drainage canals (44% of 52). The habitat distribution of otters in the Chornobyl exclusion zone corresponds well to the data for adjacent territories in Belarus and Ukraine obtained by tracking surveys in winter. This helps to produce a rough estimate of the number of Eurasian otters within the Chornobyl exclusion zone (72-153 individuals).
The valley of Orel’ river, a left bank tributary of Dnieper river, is an important breeding groun... more The valley of Orel’ river, a left bank tributary of Dnieper river, is an important breeding ground for waterfowl and waterbirds in the continental part of Ukraine. The composition and structure of waterfowl and waterbirds communities in Orel’ valley was estimated by the data of counts of breeding pairs and broods on 48 plots in 2005–2017 years. The changes of composition and structure of the communities were revealed by comparison with literature data for the periods of 1910–1920s and 1970–1980s. According to the counts data Coot (Fulica atra) (mean breeding density is 36,2 pairs/km2), Black-headed Gull (Larus ridibundus) (17,3), Black Tern (Chlidonias niger) (11,7), Great Egret (Egretta alba) (6,7), Mallard (Anas platyrhynchos) (4,5), Black-winged Stilt (Himantopus himantopus) (4,5), and Common Pochard (Aythya ferina) (4,3) are the most numerous species. The diversity of breeding species of gulls and terns has grown considerably since early XX century. The numbers of grebes, Greylag Goose (Anser anser), waders and marsh terns have declined for the last three decades. Besides, great colonies of Black-headed Gull and Black-necked Grebe (Podiceps nigricollis) have disappeared. The decline of the majority of species can be partly explained by cumulative negative impact of the fall of water level in lakes and the reduction of grazing pressure around them. However, Orel’ valley retains its important role in supporting populations of Greylag Goose and Common Pochard.
Uploads
males in 2001. Tis is higher than the population size estimated for Ukraine earlier. Obviously, this is not an actual population increase but rather a more precise estimation based on a wholerange inventory in Ukraine, which had never been done before. At the same time, fgures in the literature were based on rough estimations rather than on reliable census data. Floodplain meadows are the most important habitats supporting the largest number of Corncrakes (45–68,000, or 45-54 % of the Ukrainian population). Te highest density was observed in floodplain meadows in the forest zone (about 2-3 calling males/km2 on average, maximum 40 calling males/km2). Although Corncrake population density is usually low in agricultural landscapes, the total population number in this habitat is considerable with accounting for high percentage of agricultural land area in Ukraine. Corncrake population distribution in Ukraine is not random. The key areas are the northern and north-western parts of the forest zone (Volyn, Rivne and Chernihiv regions) where large
numbers and high population densities are observed. Tese areas are characterized by conditions favourable for Corncrake: low proportion of arable lands; signifcant proportion of relatively wet and extensively exploited meadows; well-developed system of drainage and irrigation ditches as well as availability of relatively large areas which are irregularly or scarcely used for agriculture.
males in 2001. Tis is higher than the population size estimated for Ukraine earlier. Obviously, this is not an actual population increase but rather a more precise estimation based on a wholerange inventory in Ukraine, which had never been done before. At the same time, fgures in the literature were based on rough estimations rather than on reliable census data. Floodplain meadows are the most important habitats supporting the largest number of Corncrakes (45–68,000, or 45-54 % of the Ukrainian population). Te highest density was observed in floodplain meadows in the forest zone (about 2-3 calling males/km2 on average, maximum 40 calling males/km2). Although Corncrake population density is usually low in agricultural landscapes, the total population number in this habitat is considerable with accounting for high percentage of agricultural land area in Ukraine. Corncrake population distribution in Ukraine is not random. The key areas are the northern and north-western parts of the forest zone (Volyn, Rivne and Chernihiv regions) where large
numbers and high population densities are observed. Tese areas are characterized by conditions favourable for Corncrake: low proportion of arable lands; signifcant proportion of relatively wet and extensively exploited meadows; well-developed system of drainage and irrigation ditches as well as availability of relatively large areas which are irregularly or scarcely used for agriculture.