White Stork

In contrast to the attention attracted by temporal trends of phenology, the spatial patterns of arrivals, departures or stays of trans-Saharan birds are still nowadays largely unknown in most of their European breeding areas. In the case of the white stork (Ciconia ciconia), some studies have attempted to describe its migratory patterns throughout some European countries but, to our knowledge, no one has related these patterns to some kind of explanatory variable which offers an ecologically-based explanation for the heterogeneous phenology observable among populations. Here, arrivals, departures and stays of this species, recorded in hundreds of Spanish localities, were related to a set of environmental, geographical, biological and spatial predictors, and modeled by multiple regression. The best model for arrival dates accounted for up to 34% of variability of data and pointed towards an earlier arrival in those populations located in south-western Iberia and with higher population densities. This last relationship is probably due to the competition for nest-site fidelity maintenance. However, no variable was able to explain properly the blurred spatial pattern recorded for departure dates. Departure decisions are strongly influenced by social behavior in this species and depend on collective decisions influenced by peculiar local environmental conditions of each year rather than macrogeographical gradients. Environmental, geographical or spatial variables also did not capture much of the observed variability in the length of the stays among populations. However, this variable was strongly related to the arrival and departure dates of populations. White storks stay longer in localities with earlier arrivals and, especially, later departures.

In  2016 - 2017  for  the  first  time  in  Kosovo a  pilot  project  for  White  Stork  GPS tracking  was  started.  In  2016  we  equipped  three  white  storks  (Ciconia ciconia) nestlings  and  in  2017  two  of  them  with  GPS  loggers  including accelerometers. We used this method to study the migratory orientation of juvenile white storks from  the  population  in  Kosovo  during  their  first  autumn  migration  and  also potentially important stopover sites. All data are stored and publicly available in www.movebank.org.  During  first  autumn  migration  the  storks  born  2017 covered  a  distance  of  7978  to  9790  km  from  their  nesting  site  in  Prelluzhe/ Kosovo to  their  wintering  areas  in  Tanzania.  To  reach  central  Sudan,  as  a  main first  stopover  site,  birds  needed  around  20  days.  At  the  same  time  ringing  of White  Stork  nestlings  in  Kosovo  was started.  Although  Kosovo  doesn`t  have  a national  Ringing  Center  yet,  the  first  eight  young  White  Storks  have  been marked with rings issued by Max-Planck Institute of Ornithology.  During  2016  migration,  one  of  the  birds  with  loggers  has  been  lost  in  Turkey while  two  of  them  safely  arrived  in  Sudan  but  vanished  for  unknown  reasons (presumably hunted) in November and December 2016. Those three individuals were  tagged  in  their  nesting  site  Lipjan  in  the  center  of  Kosovo.  Two  of  the tracked individuals 2017 have at the end of the year arrived in Tanzania, which is unusually stopover place for storks migrating from south-east Europe.

Nest size and nest building behaviour affect individual fitness and thus, selection may act on these traits. Most data on nesting behaviour come from species that build a nest for each new breeding attempt, whereas almost nothing is known regarding nest reusers. Here, the association between nest size and nest building behaviour, and occupation date as well as breeding success of the white stork Ciconia ciconia, a migratory species with nest reuse, is presented. Large nests were occupied earlier and showed higher breeding success, even accounting for the confounding effect of the breeder's age. In addition, nest size increased steadily over the entire breeding season and only ceased when reproduction failed. However, this increase was not related to breeding success variables. Finally, nest size was related to the number of times that it was used in the past and thus, to the probability of successful reproduction. These results suggest that storks may seek and compete for bigger nests and that nest size could be an indicator of individual and/or nest-site quality.

The diet of non-breeding White Storks was studied by pellet analysis and included mainly insects (99.9%,
n=28947) with a predominance of grasshoppers (Orthoptera, 76.1%), and beetles (Coleoptera, 26.1%). The bush crickets
Decticus albifrons/verrucivorus were the most numerous prey (29.9% by items), occurring in almost all pellets (98% occurrence
in pellets, n=147) and predominating in half of them (49.7%). The grasshopper associations in the pellets specify
foraging mainly in mesophytic grasslands that usually replace abandoned fields and overgrown pastures with a low level
of grazing. The xerophytic grass-shrubby habitats, not rare on stony terrains, were of less importance, providing around
20% by prey. The typical aquatic inhabitants and the use of carrion around villages were exceptions in the study diet. The
number of innutritious materials in the pellets rose when the White Storks hunted on nippy and agile grasshoppers and
decreased when the main pray was slower beetles taken from the ground. The roosting of non-breeding White Storks disappeared
when their preferred feeding habitats were ploughed up in the following years.

Distribution of the White Stork in the Crimea and some aspects of expansion of the species. - V.N. Grishchenko, E.D. Yablonovska-Grishchenko. - Berkut. 20 (1-2). 2011. - P. 52-64.
The White Stork is a convenient model species for the study of general regularities of bird expansion. The Crimea is a good model area for this aim. History of the appearance of stork nests here is relatively well known. Separate pairs nested in the northern and north-eastern parts of the peninsula already in XIX and XXth centuries. But it was only a pulsation of the breeding range. The nests soon disappeared. The stable breeding has started since late 1970s – early 1980s. We studied the distribution of the species in 2009–2011. In total, 32 occupied nests were registered (all of them were controlled in 2011). Overall number of the White Stork was estimated in 32–35 breeding pairs. It is increasing during last years. The distribution of White Stork in the Crimea is aggregated. There are three large remote breeding grounds in north-western, eastern and south-eastern parts of the peninsula and possible fourth one in the north near Sivash. Such aggregated distribution is typical for the White Stork on the border of breeding range. The separate breeding grounds were found also in Moscow region and many other territories from steppe to taiga. Formation of them is discussed. An other interesting feature: majority of stork nests in the Crimea (46.9%) were located near villages but not inside them. 18.8% of nests were built far from settlements. Only 6.3% of nests were located near houses. First stork nests appeared near paddy-fields and now majority of them are situated in this habitat. But in the newest breeding ground in the South-Eastern Crimea storks are not connected with this culture. Breeding of White Stork in the Crimea is fairly unsteady. The nests can vanish and appear in quite other places. [Russian].

Dynamics of arrival timing of the White Stork (Ciconia ciconia) in area of Kyiv since the middle of XIXth century. - V.N. Grishchenko. - Berkut. 25 (1). 2016. - On the base of literature sources, own observations and other data, I have compiled the almost continuous series of arrival dates since 1895. There were also observations for 1843–1852. Appearance of first storks in the area was registered (not necessarily in nests). During the whole study period, the arrival timing changed and these changes were non-linear. In general, the dynamics of dates can be described by the linear trend but the polynomial makes it more exactly. There were two periods of significant changes of timing in XXth century: at the end of its first half, arrival dates delayed and during the last decades they advanced. These periods differed not only by directions of changes but also by the duration. The first period was very brief and did not affect the overall picture. The second one was much longer and determinant the general tendency. It continued also in first decades of XXIth century. In total, since the end of XIXth century or beginning of XXth century, the speed of changes by the linear trend made about 1 day in 10 years. Results of analysis of shorter time series (significance and values of coefficient of linear regression) depended on chosen period. The arrival of the White Stork correlated with the air temperatures in Kyiv: with mean temperatures of March ((r = –0,46; p < 0,001) and the whole year (r = –0,52; p < 0,001). This relation was more expressed for the warming period since last decades of XXth century. Fluctuations of arrival dates were sizeable. The mean absolute value of deviations from the long-term average date made 5,4 ± 0,4 days (range: 1–17). The amplitude of fluctuations was not equal during the whole study period. It raised in decades with considerable changes of timing and moreover directions of deviations were synchronized. [Russian].

Population of the White Stork (Ciconia ciconia) in Ukraine in 2018: the year of contrasts. - V.N. Grishchenko, E.D. Yablonovska-Grishchenko. - Berkut. 27 (2). 2018. - In 2018 we continued the study of White Stork population on the net of monitoring plots (132 ones in 22 administrative regions with the total area of 9.9 thousands km2 and 1576 occupied nests). Information about number dynamics, breeding success, timing of migration and nesting were collected. We used the bulk of data obtained during former 26 years of observations for the comparison of annual parameters with long-term normals. The spring migration has started on 5–6 March but it was interrupted by the strong and prolonged colds in the second half of the month. In general, the timing of arrival was close to the average date. Young birds left nests also in usual period but departure of storks passed earlier. During last years the Ukrainian population of the White Stork came in the depression because of the wide-ranging and lingering drought. The number decreased in 2015 and 2016 then it stabilised in 2017. In 2018 the decline again continued. The population reduced in 2.4 ± 1.6% (± se). The number raised only in East Ukraine. The breeding success of storks greatly improved in comparison with former years of the crisis. In general, birds raised on average 2.58 ± 0.06 fledged youngs per breeding pair (JZa) and 2.85 ± 0.06 ones per successful pair (JZm). The proportion of unsuccessful pairs (%HPo) was very low: 9.7 ± 0.9%. Differences of these parameters from long-term values were significant (p < 0.05 for the average numbers of fledglings and p < 0.01 for unsuccessful pairs). In separate parts of the country the reproductive parameters were close to long-term normals or exceeded them. The breeding success was the best in North-East Ukraine. Here storks raised on average 3.39 ± 0.11 fledglings per breeding pair. It is the largest value of JZa for regions of Ukraine during the whole period of monitoring. The long-term mean (2.69 ± 0.04) exceeded by more than a quarter. Broods of 2 fledglings prevailed in West and Central Ukraine, broods of 3 ones were the most frequent in eastern and southern regions and in the Middle Dnieper Area, broods of 4 ones dominated in the north-east. We found 4 nests with 6 youngs and 1 nest with 7 youngs (third case during 27 years). These largest broods were located in the small area in the north-western part of Left-Bank Ukraine (within 4 administrative regions). We consider the extremely low productivity of the White Stork breeding in former crisis years as the main reason of the renewed number decline. The population has not enough young birds for the replacement of old storks left the ranks because of the natural mortality. The only part of the country where the number increased in 2018 is East Ukraine. Reproductive parameters did not sink here to critical values during the period of depression. Results of breeding in 2018 were explained by the distribution of precipitations within the country and continued drought. They appeared very mosaic and discrepant. We suppose that the Ukrainian population of the White Stork will continue decreasing next years. However, the raised breeding success gives hope to improvement of the situation in the near future.

State of the White Stork population in Ukraine in 2010. - V.N. Grishchenko, E.D. Yablonovska-Grishchenko. - Berkut. 19 (1-2). 2010. - P. 81-92.
Data were obtained on 99 monitoring plots in all the regions of Ukraine. They had 1218 occupied nests on the overall area 7.8 ths km2. Migration and breeding phenology, number dynamics and breeding success were studied. The year was favourable for the White Stork. The spring arrival was early. In separate regions deviations of mean first arrival dates from long-term mean dates (1992–2010) fluctuated from –7.8 to +1.4 (–3,49 ± 0,61 days (± se), 17 regions). Young birds left the nests since 10.07 till 5.08, majority of broods started to fly on 15–20.07. Mean date of the fledge is 18.07 (± 0,8 days, n = 34). The autumn passage started also unusually early. The first migrating flocks were observed in some points already in late July – early August. Last departures were registered since 16.08 till 5.10. In 2010 the White Stork population in Ukraine has renewed after drastic number decreasing in a catastrophic year 2009. On monitoring plots the number increased on average in 13,9 ± 2,4% (n = 75). It exceeded the decline in 2009 (–11,1 ± 1,5%, n = 77). The stork population has restored in the whole country and in majority of regions except the Carpathians. In Central Ukraine the renewal was incomplete (8,2 ± 5,4, n = 10 in 2010 vs. –8,3 ± 5,4, n = 8 in 2009). Storks raised on average 2,61 ± 0,05 fledged youngs per breeding pair and 2,96 ± 0,05 fledged youngs per successful pair. 11,6 ± 0,9 pairs bred unsuccessful. Reproductive parameters in 2010 some exceeded the long-term mean values. Productivity of breeding rose from the west to the east. Reproductive parameters were the lowest in the Carpathians and the highest in the left-bank part of Ukraine (to the east from the Dnieper). The highest part of unsuccessful pairs was found on 5 monitoring plots near the border of breeding range in South-East and East Ukraine but at the same time there were the largest broods here (JZm = 3,98 ± 0,12). In 2010 broods had from 1 to 6 fledglings. Majority of stork pairs raised 3 youngs (37,8%, n = 1035). 4 nests with 6 fledglings were registered in Chernigiv and Sumy regions. The share of broods with 5 fledglings rose from 0.7% in west regions to 15.0% in North-East Ukraine and 17.3% in East Ukraine. According to proposed index of favourability (Grishchenko, 2009) the year 2010 was one of the best during the period of monitoring (1992–2010). The actual number of White Stork population in Ukraine is estimated in at least 30–35 ths breeding pairs. [Russian].

Catastrophic years for the White Stork: analysis of three cases in Ukraine. - V.N. Grishchenko. - Berkut. 18 (1-2). 2009. - P. 22-40.
Normal number dynamics of the White Stork are sometimes interrupted by sharp declines. They are accompanied by the delayed arrival and the reduction of breeding success. This is an interesting phenomenon called ‘catastrophic’ or ‘disturbance’ year (German – ‘Störungsjahr’). In catastrophic years the influence of adverse factors has complex and global character. It reveals itself on large territories including many countries. During monitoring of the White Stork population in Ukraine in 1992–2009, this phenomenon was registered three times: in 1997, 2005 and 2009. Peculiarities of these years are analysed. Data were obtained from the net of constant study plots in all parts of the country. This net is representative and covers the main breeding grounds of the White Stork in Ukraine. Breeding success, number dynamics and migration timing have been investigating. For the analysis of number dynamics the obtained data are sufficient since 1994. We used the average increment of numbers on study plots in percents. In catastrophic years number decreasing was considerable: from –11,3% in 2009 г. to –16,3% in 2005 г. (Table 1, Fig. 1). In separate regions this decline was even greater. For example, in 2005 in North-East Ukraine the stork population decreased almost in a third. It is important that such number declines do not concern with tendencies of its changes in former years. In 1997 the depression fell on the peak of wave of number increasing, in 2005 and 2009 drops happened during the period of linear increasing. In all the cases the evolution of numbers did not predict following events. These jumps are indeed a catastrophic appearance nowise connected with long-term trends. There were regional differences in values of number fluctuations. In 1997 the average increasing rate had no significant differences in various parts of the country, but in 2005 and 2009 it rose from the west to the east (Table 1). The renewal of the population after catastrophic years happened differently. The drop in 1997 did not change the situation: the wave of number increasing continued. The very high increasing in 1998 (maximal during the period of investigation) fully compensated the decline and gave further growth. Moreover, it occurred synchronously in all parts of the country. Only on some study plots the renewal of number lasted 2–3 years. After 2005 the population was not restored so fast in any region of Ukraine. Furthermore, in West Ukraine continued the small number decreasing. Reproductive parameters also were appreciably decreased in catastrophic years. They had the minimal values during 18 years of observations in 1997 (Fig. 2, Tables 2, 3). Catastrophic years have started with the delay of migration of storks. Mean dates of the first arrival distinctly overstep the limits of usual fluctuations (Fig. 3). But in separate points the birds can appear in normal times. In catastrophic years timing of migration was prolonged. If for 15 normal years the standard deviation of first arrival dates made on average 7,59 ± 0,34 (5,2–9,9), then for three unfavourable seasons it rose to 10,47 ± 0,37 (9,8–11,0). The difference is significant (t = 3,68, p = 0,002). Features and reasons of catastrophic years are discussed. A year can be considered as catastrophic if 4 conditions meet: 1) delay of the arrival, 2) number decreasing, 3) reduction of the reproductive success, 4) these phenomena take place in a large territory. Reasons of catastrophic years are now well known. First of all these are the adverse conditions of wintering and to lesser extent problems during the spring migration. Already there are many data evidencing that population dynamics of long-distance migrants to a great extent are determined by conditions in wintering grounds. Survival of adult birds and for many species also result of breeding depends on them. The White Stork was one of the first birds for which these regularities were studied. Close correlation between the number dynamics and the breeding success of the White Stork in Ukraine was found (Table 4). It means that fluctuations in both cases are determined by the same factors. First of all, these are the conditions in wintering grounds. Therefore, the wintering area serves as a peculiar regulating system extensively determining the state of the population. This connection can be shown not only in extremal years but also in quite normal breeding seasons. In population dynamics of the White Stork the influence of global factors predominates. It can be good shown comparing number dynamics in Ukraine and in Germany (Fig. 1). These countries are located at the opposite ends of the breeding range of the Eastern White Stork population, but number fluctuations correlate very close (r = 0,91, p < 0,001). For the comparison of years with each other two indexes based on normalized deviates of three main parameters are proposed (ta – n. d. of mean arrival date, tn – n. d. of mean increasing rate, tf – n. d. of mean number of fledged youngs per breeding pair, JZa). Index of disturbance Id is a mean absolute value of normalized deviates in a catastrophic year: Id = (|ta|+ |tn| + |tf|)/3. Index of favourability If is the sum of normalized deviates with the corresponding sign: If = tn + tf – ta. 1997 was the most unfavourable year during the study period. Ukrainian storks belong to the Eastern core population by H. Schulz (1999). But it is not a single whole and can be separated in two parts: the core one and the peripheral one. The peripheral part has many differences from the core part, it is more reactive and unstable. [Russian].

State of the White Stork (Ciconia ciconia) population in Ukraine in 2012. - V.N. Grishchenko, E.D. Yablonovska-Grishchenko. - Berkut. 21 (1-2). 2012. - P. 50-63.
The year 2012 was 21st one of monitoring studies of the White Stork in Ukraine. Data analysed were obtained on 132 monitoring plots in all the regions of Ukraine. They had 1652 occupied nests on the overall area 9.6 ths km2. Migration and breeding phenology, number dynamics and breeding success were studied. The year was medium for the White Stork population in Ukraine by majority of parameters. Timing of the spring arrival was close to average dates. In separate regions deviations of mean first arrival dates from long-term mean dates (1992–2012) fluctuated from –3.2 to +4.0 (0.03 ± 0.55 days (± se), 14 regions). Young birds left the nests since 5.07, majority of broods started to fly on 15–25.07. Mean date of the fledge was 21.07 (± 0.3 days, n = 58). The autumn passage went also in usual terms. The first migrating flocks were observed on average on 16.08 (± 1.6 days, n = 20, lim: 30.07–28.08). Last departures were registered since 20.08 till 8.10 (average – 1.09, n = 30). In 2012, the White Stork population in Ukraine has slightly increased. On monitoring plots, the number rose on average in 3.4 ± 1.3% (n = 108). The largest number increasing was registered in Central Ukraine (10.0 ± 3.4%, n = 15). Reproductive parameters were close to long-term means. Storks raised on average 2.50 ± 0.05 fledged youngs per breeding pair (JZa) and 2.78 ± 0.04 fledged youngs per successful pair (JZm). 10.2 ± 0.9 pairs bred unsuccessful. Productivity of breeding rose from the west to the east. It was expressed to the greatest extent in northern part of Ukraine. The peculiar gradient was traced across the forest zone from Volynia to Chernigiv region. Reproductive parameters were the lowest in West Ukraine to the North from the Carpathians (JZa = 2.08 ± 0.05; JZm = 2.35 ± 0.05; n = 40) and the highest in North-East Ukraine (JZa = 3.04 ± 0.13; JZm = 3.25 ± 0.11; n = 17). Broods had from 1 to 6 fledglings. Majority of stork pairs in Ukraine raised 3 youngs (40.1%, n = 1445). Frequency graphs varied for different regions. In West Ukraine 47.6% of stork pairs raised only two youngs. The largest number of big broods was found in South-East Ukraine: 47.8% of them had 4 fledglings. Only one nest with 6 young storks was registered in Chernigiv region. The proportion of broods with 5 fledglings varied from full absence in Central Ukraine and the plain part of West Ukraine to 10.9% in north-eastern part of the country. [Russian].

The study originated when we took note of diverse and large concentration of wetland birds during an ecological study of the Gharial (Gavialis gangeticus) in National Chambal Sanctuary. Simple field notes from October 1983 to February 1986 were made to provide date, place(s), species of birds and the number of each large wetland bird. Results provide information on preliminary checklist with remarks on whether resident or visiting (migratory), the seasonal fluctuation in number in case of large migratory species, and the localities along the river Chambal where good numbers of different birds were sighted. Sixty-three species of wetland birds in eighteen families and fifty-six species of other birds in twenty three families have been listed. Thirty-two wetland species were resident thirty-one wetland species were visitors. Comparative accounts have been provided on species that were listed for Chambal and Bharatpur of Rajasthan earlier. As bird-sighting was incidental to gharial work, we later understood that we have missed seven wetland species and twelve other species recorded by Mitra (1979) and most birds listed from Bharatpur in the BNHS Avifauna Project Reports and Hancock (1984). However, four species of birds in our list were not reported in the region (of Chambal and Bharatpur) earlier. These are the Little Green Bittern, Black Stork, Black-headed Gull and Grey Wagtail. Seasonal analysis of data showed that (i) Teals and Poachards appeared first in northern portion of Chambal Sanctuary and then in southern parts; (ii) Brahmini duck, Bar-headed Geese, White-necked stork, common crane and Demoiselle crane also appeared first in the northern portions; (iii) Open bill storks were rare in the northern portion; (iv) Black stork, White stork, Coots, Flamingos, White Ibises and Jacana were considered occasional visitors. Fifteen species showed congregations of more than 25birds. Seventy numbers of White-backed vulture and three King vultures were recorded during the study. There were several ‘favoured localities’. The Bar-headed geese were close to cultivated areas; White-necked stork and Black-necked storks were confirmed predators of eggs of Kachuga tentoria even on islands; Plovers and Lapwings were secondary predators; the abundance of Sarus cranes and Painted storks near crocodile nursery sites made us believe that they were active predators on crocodile hatchlings as most of the hatchlings disappear by the end of monsoon. The entire work was viewed as a stimulant for serious ornithological survey in future.

State of the White Stork population in Ukraine in 2011. - V.N. Grishchenko, E.D. Yablonovska-Grishchenko. - Berkut. 20 (1-2). 2011. - P. 37-51.
Data analysed were obtained on 125 monitoring plots in all the regions of Ukraine. They had 1502 occupied nests on the overall area 9.3 ths km2. Migration and breeding phenology, number dynamics and breeding success were studied. The year was very unfavourable for the White Stork because of bad weather conditions: cold and protracted spring, enduring drought till mid June and heavy torrential rains in late June – early July. Timing of the spring arrival was close to average dates. In separate regions deviations of mean first arrival dates from long-term mean dates (1992–2011) fluctuated from –4.1 to +4.6 (0.11 ± 0,79 days (± se), 11 regions). Young birds left the nests since 10.07 till 14.08, majority of broods started to fly on 18–25.07. Mean date of the fledge is 21.07 (± 0.7 days, n = 77). The autumn passage went also in usual terms. The first migrating flocks were observed on average on 16.08 (± 2.3 days, n = 11, lim: 4.08–25.08). Last departures were registered since 17.08 till 28.09 (average – 31.08, n = 29). In 2011, the White Stork population in Ukraine remained practically stable. On monitoring plots the number increased on average in 2.3 ± 1.5% (n = 97). In separate parts of the country, the numbers fluctuated in different ways without definite trends. Only in the Carpathians the population essentially increased. The average gain of number on 6 study plots made up 16.4 ± 7.6%. The Carpathian population of the White Stork has restored with delay in one year after the decline in catastrophic year 2009. In 2010, the renewal was incomplete. Reproductive parameters were lower in 2011 than long-term mean values. Storks raised on average 2.26 ± 0,05 fledged youngs per breeding pair and 2.60 ± 0,05 fledged youngs per successful pair. 13.0 ± 1.2 pairs bred unsuccessful. Productivity of breeding rose from the west to the east. Reproductive parameters were the lowest in West and Central Ukraine and the highest in South Ukraine. The maximal number of youngs storks raised in the south-east part of the country (JZa = 2.94 ± 0.32; JZm = 3.52 ± 0.22; n = 6). In 2011, broods had from 1 to 6 fledglings. Majority of stork pairs in Ukraine raised 2 youngs (39.5%, n = 1249). It is characteristic only for very unfavourable years. Frequency graphs varied for different regions. In West and Central Ukraine about the half of stork pairs raised two youngs but in other parts of the country maximum fel on broods with three youngs. 2 nests with 6 fledglings were registered on the lower Dnieper in Kherson region. The proportion of broods with 5 fledglings rose from 0.4% in West Ukraine to 9.5% in east regions and 10.8% in South Ukraine. In Central Ukraine and in the Carpathians they were not found at all. The year 2011 was very bad for the White Stork but it is not a catastrophic year. Its parameters do not correspond to the formerly described criteria (see Grishchenko, 2009). [Russian].

Number dynamics of the White Stork in Ukraine in 1994–2003. - V.N. Grishchenko. - Berkut. 13 (1). 2004. - P. 38-61.
White Stork is a convenient species for the analysis of patterns of population dynamics. Moreover, reasons of general and synchronous number increasing remain in many respects not clear. In Ukraine number dynamics of the species is influenced by two factors during many years: general changes in numbers and continuing expansion of the White Stork to the east. Therefore trends differed in east regions and in other parts of the country. In Ukraine in 1992 has started the program of monitoring of the White Stork population. Ornithologists and voluntary helpers take part in observations. Data are obtained on the net of constant study plots in different regions. They let control breeding success and number dynamics in the country. In total the information from 134 plots in 22 regions of Ukraine is obtained in 1992–2003. On 63 from them observations were carried out during 3 and more years, on 15 ones – during 10–12 years, on 1 – 17. Since 1994 the obtained data are sufficient for the analysis of number dynamics. Considered ten years cover the period between Vth (1994–1995) and VIth (2004–2005) International White Stork Censuses. For the analysis of population dynamics the average increment of numbers on study plots in % were used. Since 1994 the increase of number permanently rose (Fig. 1). Maximum of increasing was registered in 1996 and 1998. In 1997 number of the White Stork has sharply decreased. This year was catastrophic for the species almost in whole Europe. It was caused by bad conditions during wintering and spring migration. Already the next year population was completely restored and number increasing continued. Since 1999 rate of growth began to decrease and last years population was stabilized. Comparison of dynamics of number increasing in three large regions of Ukraine (Fig. 2) shows that this process has firstly started in North-East Ukraine, the greatest increase of number was registered also here. In 1994–1998 numbers changed in all three regions synchronously. Later this synchronism was reduced and last years changes went discordantly. Ceasing of number increasing after 2000 was registered also in other countries, for example in Germany. Expansion of the White Stork has wave-like pattern. One of such waves in fact was traced during the period of observations. This wave has started in Ukraine with number increasing early in 1990s. Enlargement of the breeding range was observed in east regions of the country. At the same time the expansion livened up in Russia. General questions of expansion and number increasing of the White Stork are discussed. In Ukraine the number increased first of all and to a greatest extent in optimal habitats with low population density. Expansion of the White Stork in East Europe can be considered as filling of “faunistic emptiness” remaining in North Palearctic after the last glaciation. The expansion is vectorial. In East Europe it goes to the east, a lesser degree – to the north, but not to the south. This phenomenon can be connected with genetic determination of direction of young birds dispersal in population near the east border of the breeding range. Such “directed” population can be formed by the natural selection. Mechanism is similar to genetic control of partial migration well studied by P. Berthold and colleagues. If different directions of dispersal are equal for the population, existing various genetic programs of dispersal will remain in the same ratio. But if one of the directions give a preference in breeding success, the part of birds with this variant of the program will increase. “Vector of expansion” can be predetermined also by other factors. For example, dispersal goes on the way of “minimum resistance”, on areas having favourable conditions for breeding but with low population density of storks or full absence of them. At last, combination of endogenous and exogenous control of dispersal is possible. Breeding success of the White Stork is higher in east part of the breeding range: in Ukraine (the Dnieper area and eastwards from this river) and in many regions of Russia. This fact explains a well known contradiction: storks continued advance to the east in spite of number decreasing of the species and depression of populations in many countries. The east part of breeding range are all-sufficient for the expansion: high breeding success and predominant direction of dispersal create the necessary prerequisites for further moving eastwards in spite of the situation in other parts of the breeding range. In Ukraine the negative correlation between population density and breeding success of the White Stork was not found. Probably ecological capacity of environment is far from the saturation and population density is not a limiting factor. It creates prerequisites for further number increasing. Only on one large area in Ukraine considerable number decreasing of storks was noted: they almost stopped breeding in Chernobyl exclusion zone in 1990s. But it is connected not with population trends. This area became unsuitable for the White Stork because of evacuation of people and desolation of agricultural lands. Close correlation between changes of numbers and breeding success was found (Table 2). It means, that dynamics in both cases are caused by the same factors. First of all these are conditions in wintering area. Their influence on eastern population of the White Stork is discussed. It is supposed that reasons of its rise are also connected with African wintering grounds. May be global climate changes in Africa have caused the improvement of food supply for wintering storks. It promoted increasing the survival rate and breeding success and was an impuls for synchronous changes in numbers on the territory of whole breeding range of the European subspecies. Number of White Stork in Ukraine in 2003 is estimated at least in 25000–30000 breeding pairs. [Russian].

Breeding success and number dynamics of the White Stork (Ciconia ciconia) in Ukraine in 2014–2016. - V.N. Grishchenko, E.D. Yablonovska-Grishchenko. - Berkut. 25 (2). 2016. - We studied the main parameters of the White Stork population on a net of permanent monitoring plots. This project has started in 1992. The net of plots constantly developed and enlarged. Number dynamics, breeding success, migration and nesting phenology were explored. The vast material obtained during 25 years allows to compare data for a year with long-term normals. In 2014–2016, we with voluntary helpers controlled 143 plots in 22 regions of Ukraine, 115 to 133 in a year. The total area of them amounted to 8.6–9.3 ths km2. The net had 1611 to 1929 occupied nests of storks, 3 to 62 nests on a plot. Arrival was early in these three years. In 2015 and 2016, fledglings left their nests in usual times, in 2014 – earlier. All three years were unfavourable for breeding of storks. Reproductive parameters in 2014 and 2016 were essentially below the long-term average values, the year 2015 became one of the worst during the whole period of our observations. Storks raised on average 1.86–2.28 fledged youngs per breeding pair (JZa) and 2.37–2.66 ones per successful pair (JZm). JZa-values made only 76.5–93.8% from long-term normals, JZm-values – 85.3–95.7%. From 15.4 to 22.5% of pairs bred unsuccessfully (116.2–169.9%). The worst situation developed in West Ukraine. Storks produced here only 1.71–1.73 fledglings per pair (JZa) in all three years (25-year average: 2.21 ± 0.02). The number increased in 2014, but since 2015 it began to fall. The stork population in Ukraine decreased in 4.9% in 2015 and in 4.0% in 2016. Changes of number went in different parts of the country discordantly, therefore the total decline was moderate. In separate regions it amounted to 8–10%. The largest number decreasing was observed in the Forest Zone (northern regions). At the same time the population of storks increased in South-East Ukraine. The main reason of these negative events was the enduring and intense drought embraced the vast territories. The Ukrainian population of the White Stork came in the period of depression that caused by unfavourable conditions in the breeding area. It proves itself in very low productivity of breeding and number decreasing. The first signs of this depression have appeared in the west of Ukraine in 2014, in 2015 and 2016 it covered already the whole country.