Project Report

"Monitoring of Aquatic Warbler Breeding Groups in Ukraine in 2017”

Report prepared by Dr. Poluda Anatolii

Participants of survey:

Poluda Anatolii Khymyn Mykhailo Iliukha Oleksandr Korkh Yurii Leheida Ivan Frankov Serhii

Ukrainian Society for the Protection of Birds

KYIV, 2017

2 Summary

In 2017 the most important breeding areas of both population groups of Aquatic Warbler in Ukraine were surveyed. In particular, eight breeding areas th th of the Desna-Dnipro population were visited from 1 till 8 June (7 days evening censuses). Four persons participated in the survey. Monitoring of the th th Prypiat population groups was performed from 23 June till 2 July, and nine evening censuses were carried out. Also four persons participated in the survey. The censuses covered 865 ha out of 1,180-1,280 ha of suitable habitat in the breeding sites of Desna-Dnipro population (66-68%). 102 males were recorded there. In the breeding sites of Prypiat population 542 males were recorded on 966 hectares. This is about 14-15% of the total area of suitable habitats of the Prypiat population (6,615-6,715 ha). During the survey of the breeding sites of the Desna-Dnipro population hydrological conditions were not optimal for most parts of the surveyed area. Due to artificial structures (sluice, dam), optimal conditions were only found in the breeding sites UA-05. Udai valley “Dorohinka-Monastyryshche”, UA-08 “Horodok” and UA-06. Halka valley “Halka”. However, in the last site no AW have been registered. Three breeding sites were completely dry – in the key territory UA-01. Supii valley “Vilne-Berezanka” only 2 males were counted, in UA-07. Perevid valley “Paskivshchyna” – only 1 male, in UA-04. Supii valley “Voronky” – 0. In 2017 in two out of eight breeding sites no AW have been recorded (UA- 04. Supii valley “Voronky” and UA-06. Halka valley “Halka”). In the latter case, the reasons for this are not clear, since the conditions for nesting were optimal. The number of birds declined catastrophically in five breeding sites – Supii valley: UA-01 “Vilne-Berezanka”, UA-02 “Bykiv” and UA-03 “Bilotserkivtsi”, UA-07. Perevid valley “Paskivshchyna”, UA-08 “Horodok”. Only in one territory (UA-05. Udai valley “Dorohinka-Monastyryshche”) the situation was better than in the previous two years. The total AW number of all the eight surveyed breeding sites of the Desna-Dnipro population was estimated at 217-275 males only . For comparison, in 2016 the AW number was estimated at 153-220 males, in 2015 – 300-375, in 2014 – 450-500.

In 2017 the survey of AW breeding territories of the Prypiat population were carried out at 15 breeding sites, but two of them were only visited during daytime (UA-11. Upper Prypiat, area to the east from Turiia mouth and UA-29. Stokhid valley, area near St.Chervyshcha). During the breeding season, the situation with the water level in the AW sites of the Prypiat population was similar to that in the breeding territories of the Desna-Dnipro population. For the fourth consecutive year, no spring floods occurred in the Prypiat river basin. This often leads to burnout of the AW habitats. 3 During our surveys, optimal water conditions occurred only in two AW sites (UA-24 lakes Bile and Pisochne and UA-25 Chornohuzka valley “Tseperiv-Baiv” and on a small part (not more than 10%) of UA-14 “Vetly- Birky”). At the other breeding sites the water level was below the ground. In 2017, the AW number has increased in almost all the breeding sites compared to the last year's season. Only in UA-09 “Richytsia-Pidhiria“ the number has not changed, and UA-24 lakes Bile and Pisochne and UA-25 Chornohuzka valley “Tseperiv-Baiv” numbers have slightly decreased. The total AW number of the Prypiat population was estimated at 2,850-3,280 males (Annex 2, Table). The total AW number in Ukraine in 2017 is estimated at 3067-3555 males.

We are very grateful to our German colleagues and Ukrainian Society for the Protection of Birds for the financial support of this survey.

4

Introduction

There are two population groups of breeding Aquatic Warblers in Ukraine – the Desna-Dnipro and the Prypiat population. In recent years, when surveys of the two groups were performed, the size of the Ukrainian population was estimated as follows: 3,800-4,365 males - in 2008, 4,000-4,750 in 2009, 4,200- 4,900 – in 2010, 3,450-4,050 – in 2012, 3,400-3,780 – in 2014, 3,050-3,375 – in 2015, 2,010-2,315 – in 2016 (the actual number this year, most likely, was 200-300 males higher).

Terms and Method of Research

In 2017 the most important breeding areas of both population groups of Aquatic Warbler in Ukraine were surveyed. In particular, all eight breeding th th areas of the Desna-Dnipro population were visited from 1 till 8 June (7 days with evening censuses). O. Iliukha, S. Frankov, M. Khymyn and A. Poluda participated in the survey. Monitoring of the Prypiat population group was th th performed from 23 June till 2 July (9 days with evening censuses). M. Khymyn, Y. Korkh, I. Leheida and A. Poluda participated in the survey.

AW censuses are conducted with the method developed by the International Working Group on the Aquatic Warbler (Aquatic Warbler Conservation Team, 1999). In the Aquatic Warbler habitats 200 m wide and 1- 1.5 km long transects were surveyed. These surveys began 30-40 minutes before sunset. The number of males at a site was calculated by extrapolating the results of transect counts to the entire area of suitable AW habitat at the site. Besides assessing the number of birds in a definite grouping, the state of plant associations and the hydrological conditions of the habitat were determined (pits were dug on the most nesting areas to control the water level).

Results and Discussion

Desna-Dnipro Population

During the survey of the AW breeding areas (01.06.-08.06.2017) hydrological conditions were not optimal in most parts of the sites. Since four years (2014-2017) there have been no spring floods in this region. In spring of 2017 the water level in the valleys of small rivers was significantly lower than 5 before the period 2014-2017(Annex 2, Fig. 1). Due to that situation some breeding territories were completely burned. An illustration of the unfavourable hydrological situation is the fact that the river Supii did not flow at all between Svydovets and Yahotyn.

UA-01. Supii valley, area between Vilne and M. Berezanka (Vilne- Berezanka) Aquatic Warbler occupies a part of the floodplain of river Supii, which is a eutrophic sedge marsh. The total area of AW habitat is about 260 ha (Annex 1, Map 1). The data on the water level in the monitoring area in general show a rather sustainable water regime. As a rule, the water level in the monitoring pits ranged from -3 to +12 cm in May and June. In the first 10 years of observation (since 1995), only in one season (June 2003) the water level in the breeding period was low (-5 cm) (Annex 2, Fig. 2). However, since 2011, there have generally been low levels of water in the breeding season. The water level in water point was +2 cm in June 2010, it was -10 cm in the third decade of May 2011, -6 cm – in the first decade of June 2012, -2 cm – in the third decade of June 2013, +2 cm – in the second decade of June 2014, -9 cm – in the first st decade of June 2015, +2 cm – in the first decade of June 2016. In 2017 (1 decade of June), the water level was -20 cm. During the survey the whole breeding area (from the southern to the northern border) was completely dry – the water level was 20-60 cm below the ground (Annex 2, Fig. 2). This is the lowest level of water since 1995. As result in winter and spring most of the AW territory burned out (about 70%). In this season we carried out two evening censuses, which covered the whole breeding site. On the monitoring plot (40 hectares) no AW have been recorded. For comparison, on the same plot in 2016 2 males were registered, in 2015 – 12, in 2014 – 13, in 2013 – 22, and in 2012 – 16. A total of only 2 males was counted in the whole area. The total number of AW of the breeding group has become critically low – only 2 males (in 2016 it was 15-20 males, in 2014-2015 – 70-80 males, in 2013 – 90-100 males, in 2012 – 80-90 males, in 2010 – 140-160 males). It is possible that next year there will be no AW at all.

UA-02. Supii valley, area near Novyi Bykiv (Bykiv) The AW group occupies the western half of the Supii river floodplain. The breeding area is about 50 hectares. The highest AW number occurred in 2005 (20-25 males). In 2017 both the water conditions and the state of vegetation were more or less optimal for AW. Due to a natural decrease in the floodplain of the river, the AW habitats at a distance of 100 m from the edge of the marsh were wet. In some places there was open water. The habitats did not burn. Despite this, only 2 males were recorded on the whole territory. In 2016 the estimated number 6 was 14 males, in 2015 – 8-10, in 2014 – 12-15.

UA-03. Supii valley, area near Bilotserkivtsi (Bilotserkivtsi) This AW breeding group is located on the western half of the Supii river floodplain, the total area is about 100 ha. In recent years we have seen significant dynamics of AW numbers in this breeding territory: in 2013 – 20-15 males, in 2014 – 3-5, in 2015 – 25-30. The reason of such AW dynamics is most likely to be the redistribution of birds between other breeding areas nearby, in particular, UA-02 and UA-04. In 2017 the water level was the lowest for the entire period of our observations. It was 50 cm below the ground. However, due to a natural decrease in the floodplain of the river, the AW habitats in “the depths of the floodplain” were wet. During evening census 7 males were counted exactly on these wet areas. The total number of AW was estimated at 7-10 males.

UA-04. Supii valley, area near Voronky (Voronky) The AW group occupies the floodplain of the upper river Supii located just 4 km from the source of the river. This part of the floodplain Supii is a eutrophic low grass sedge marsh dominated by horsetail-sedge associations. The total area of habitat is about 60 hectares. The water regime in places occupied by AW is characterized by water flow across the whole width of the floodplain and along the formed river bed. The water level in the breeding habitats maintains its rising and forms its southern boundary. Normally the water regime is optimal for Aquatic Warbler, breeding there every year. In recent years we noted strong dynamics of water level in this territory. In 2013 and 2015, the habitat was completely dry – the water level in the monitoring pit was -60 and -75 cm, respectively (which corresponds to 40 and 55 cm below the ground level in the AW habitats); in 2014 and 2016 the water level was at its optimum (-18 and -21 cm or 2 and -1 cm compared to the ground level). The number of Aquatic Warblers ranged from 6 (2000) to 20 males (2003- 2006.). Since 2007 the number has been low (not more 10-12 males). For example, in 2012 the number was estimated at 5-6 males, 2013 – 2, 2014 – 10- 12, 2015 and 2016 – 0. In 2017 the AW habitat was completely dry – the water level was 35 cm below the ground level and did not burn. During an evening census no male was registered.

UA-05. Udai valley, area between Dorohinka and Monastyryshche (Dorohinka-Monastyryshche) The breeding group of AW is located in the Zhevak mire and in the floodplain of river Udai (Annex 1, Map. 1). The total area of suitable habitat is about 600 ha. The water regime in the AW breeding sites is supported by a sluice, which 7 is located 3 km downstream of the territory. The fluctuations of water level are not significant due to a vegetation layer with water, sapropel and peat beneath it. Almost all the AW habitat is covered with club mosses. The club mosses (vegetation layer) rise or fall with the water fluctuations that essentially eliminate water fluctuations at the habitat surface. The range of fluctuations of water level is not more than 9 cm directly in the vegetation cover. Fifteen years of monitoring of this group shows that the number of birds is relatively stable due to the stable hydrological conditions in the AW breeding sites. The total number of the Aquatic Warblers in the settlement usually ranges from 250 to 360 males. Since 2014 there occurred a strong decrease in the number of AW in this key site. In 2013 the number was 340-360 males, in 2014 – 300-320, in 2015 – 150-200 (in 2015 the water level was the lowest since 1998 and greater part of the area has burned), in 2016 – 100-150 males (water regime and plant cover were optimal). In 2017 situation with AW has become a little bit better. During our survey AW habitats were optimal (hydrological and vegetation conditions). The water level in the pit at the edge of the mire (bank) was very low (-50 cm). At the same time in the AW habitats the water level was 5-15 cm above the mire surface (“ground”). The result of census on the monitoring route (30 hectares) was optimistic for us – 25 males were counted (Annex 1, Map. 1) (for comparison, on the same route have been counted: in 2016 – 9 males, in 2015 – 18, in 2014 – 44, in 2013 – 36 male). At the same time, another 16 males were counted on 55 hectares of habitat in the floodplain of the Udai river (water regime was optimal here). On this plot, also 16 birds were counted in 2016, 17 in 2015 and 18 in 2014. In addition, evening censuses were carried out in other plots – to south and to west of the monitoring plot. The areas of these plots were 60 and 40 ha, respectively, and 24 and 20 males were counted there. The total population of this group was estimated at 200-250 males.

UA-06. Halka valley, area between Bohdanivka and Leonidivka (Halka) The Aquatic Warblers occupy the floodplain part of the Galka river, which is a tributary of the Udai river. The first evening census was carried out in late May 2005, 12 males were counted on an area of about 40 hectares (right bank of floodplain). In 2006-2007, new breeding habitats were found; their total area was 120 hectares. The number of the AW was 30-35 males at this site. In 2013, we found a very strong transformation of most of the breeding habitats on the left bank of the river floodplain – the height of vegetation (mainly sedges) reached 1.5-1.6 m and plant density was high. The reason of the eutrophication of habitat was organic pollution by a livestock complex. The AW number was not more than 13-15 males in that season. 8 In 2014 the total number was estimated at 20-25 males. In 2015, after the eutrophication of AW habitats in 2012-2013, we observed a process of improvement of AW habitats. The total number was estimated at 9-10 males. In 2016 we performed an evening census on the whole territory. The water level in the breeding habitat was the highest for all the years of monitoring. The vegetation cover in the left-bank part was optimal (recovered after the transformation 2012-2014). However, only one male was recorded there. On the right bank 3 males have been counted. The total number of this group was estimated at 4-5 males. In 2017 the whole breeding area was surveyed but no male was registered, despite the fact that the site was optimal for the Aquatic Warbler relating to both, hydrological regime and vegetation.

UA-07. Perevid valley, area near Paskivshchyna (Paskivshchyna) The AW group occupies the floodplain part of the Perevid river, which is a tributary of the Udai river. Its total area is over 50 hectares. Water regime in the breeding habitats is optimal for the AW, because even in dry years, like 2007, water was above the ground surface in most of the habitats. In 2014 (June) we firstly observed a very low water level in the floodplain Perevid river – a 100-meter strip along the edge of the floodplain was dry. In other years the AW numbers have been estimated between 12 and 25 males. In 2017 the situation on the AW breeding territory was critical – the water level was very low (more than 30 cm below ground). As a result, the whole site was dry. Besides, it burned completely including tussocks. 1 male was counted during the evening census.

UA-08. Mire near Petrivka (zakaznik “Horodok”) (Horodok) The AW grouping occupies the ancient floodplain part of the Snov river, which is now separated by a road-dam from the recent river floodplain. The Snov is a tributary of the Desna river. The total area of this breeding site is about 40 ha. The AW number ranged from 12 to 30 males. The water regime of this territory is supported by two sources – melting water and atmospheric precipitation. In 2017 water and plant conditions were suitable for AW (but water level was below the optimum). 5 males were counted during evening census. The AW number is estimated at 5-10 males, considering that the song activity was very low.

To summarize: All eight breeding areas of the Desna-Dnipro population th th were visited from 1 till 8 June (7 evening censuses). Four persons participated in the survey. The censuses covered 865 ha out of a total of 1,180- 9 1,280 ha of suitable habitats (66-68%). 102 males were recorded there. Conditions for nesting were favorable only in three breeding sites (Udai valley UA-05 “Dorohinka-Monastyryshche”, UA-08 “Horodok”, Halka valley UA-06 “Halka”). However, in the last site no AW has been recorded. Three breeding sites were completely dry – in the key territory Supii valley UA-01 “Vilne- Berezanka” only 2 males were counted, in Perevid valley UA-07 “Paskivshchyna” – only 1 male, in Supii valley UA-04 “Voronky” – 0. The total AW number of all the eight surveyed breeding sites was estimated at only 217-275 males (Annex 2, Table).

Prypiat population

During four consecutive years (2014-2017) in the river valleys of the Volyn region occurred no spring flooding - the water did not exceed the river beds to inundate the floodplain (Annex 2, Fig. 3). This led to the fact that most section areas of the mires were burned out in spring (or in autumn, or in winter).

UA-09. Upper Prypiat, area between Richytsia and Pidhiria (Shchedrohir) (Richytsia-Pidhiria) The total area of suitable AW habitat is about 250 hectares. The number of AW ranged from 80-100 to 300-350 males over the past 12 years. The monitoring area is located in the eastern part of the breeding site. In optimal seasons, the suitable AW habitat is 120 hectares, in more dry years nearly 90 ha. Results of bird censuses on the monitoring plot (30 ha): in 2014 only 3 males; in 2015 – 19 (total number in this area of 120 ha was estimated at 70-80 males and the total for the whole site at 150-180 males); in 2016 – 5 males on 10 ha (daytime). In 2017 the AW habitat was very dry (the water level in the monitoring pit was 35 cm below the ground (Annex 2, Fig. 4), but during winter and spring no fires occurred. During evening census 16 males were counted on an area of 30 ha (Annex 1, Map 2). At the same time on an area of 40 ha (2 km to west) 22 males were registered. It can be assumed that in the monitoring area (90 hectares) 45-60 males occurred. We estimated the total number for the whole breeding group at 130-150 males. In 2006-2007, works on deepening the riverbed were carried out between the villages of Richytsia and Shchedrohir and about 4 km of the main riverbed was deepened. As a result, the water level dropped significantly in the floodplain, including our monitoring site (Annex 2, Fig. 4). In particular, the water level of the lake Strybuzh and the adjacent parts of the floodplain decreased by more than 50 cm in 2008. The floodplain part of the river between the villages of Richytsia and Shchedrohir was examined by boat on 25.06.2017 (before this, surveys were 10 conducted on 21.06.2012 and 15.07.2014). In those parts of the river, where deepening of its channel was carried out in 2006-2007, there were no traces of these works any more – the bottom of the river was restored (there were rapids, shoals), there were no bottom sediments (they were washed during floods and this mule "came back" into the river); a significant part of the mule came into the floodplain speeding up the negative transformation of plant associations.

UA-10. Upper Prypiat, area between Pidhiria (Shchedrohir) and Turiia mouth (Pidhiria-Turiia mouth) The total area of the AW breeding habitat in this area is about 175 hectares (Annex 1, Map. 2). After deepening the riverbed in 2006, the river kept playing the role of a drainage channel draining the floodplain. In 2017 all AW habitats were dry – on a plot located near Lake Krupyne the water level was 44 cm below the ground (in 2015 – -70 cm, in 2012 – -50 cm, in 2010 – -1 cm, in 2009 – +3 cm, in 2008 – -10 cm). The habitat (15-20 ha) was not burned and during daytime no male was recorded. During evening census 12 males were counted on the western habitat (next to the road to Shchedrohir). The area of census was 10 ha; the total area of suitable habitats of the plot is 70 ha. The site was completely dry and not burned. The AW number is estimated at 80-100 males (in 2016 – 60, in 2015 – 70- 80, in 2014 – 5-10 males). On 26 th June 2017 we passed this section of the river by boat. Further improvement in this area, compared with 2012 and 2014, was observed. However, the recovery rate here is lower than in the upper part of the river.

UA-11. Upper Prypiat, area to the east from Turiia mouth (Prypiat- Turiia). UA-12. Upper Prypiat, area to the east from canal Vyzhevskii (canal Vyzhevskii)). UA-13. Upper Prypiat, area to the south of Nevir (including mire “Zalissia”) (Nevir-Zalissia) These three sites are one AW breeding group. Perhaps you could add the AW site UA-19 Upper Prypiat, area near Volianske lake and canal “Khabaryshche” as well that adjoins this territory from the north. It begins from the mouth of the Turiia river and extends to the eastern edge of the village Nevir. The total area of the floodplain is more than 4,000 hectares. The area of potential AW habitats is over 1,000 hectares. In optimal years, AW number was estimated at 450-550 males. In 2014, the total number was lower than usually at c. 300-350 males. In 2017, evening censuses were carried out in the eastern part of the breeding site (south and south-east of Nevir) (Annex 1, Map 3). The AW habitats were dry. We surveyed two plots of 35 and 20 ha. 20 and 3 males were counted respectively. Besides, the survey of one plot (20 ha) in the eastern part of the breeding site was carried out during daytime. 7 males were counted (Annex 1, Map 3). During daytime we visited one plot of UA-11 (Annex 1, 11 Map 4). 6 males were recorded on an area of 10 ha. For 2017, we estimate the total number for the whole breeding site (UA-11, UA-12, UA-13) at 260-340 males .

UA-14. Upper Prypiat, area between Vetly, Birky and Tsyr (Vetly- Birky). UA-15. Upper Prypiat, area between Vetly, Hirky and Liubotyn (Hirky-Liubotyn) The largest breeding group of the Aquatic Warbler in Ukraine is situated in the Prypiat and Tsyr river floodplains between the villages of Vetly, Hirky, Tsyr and Birky. This territory has an area of almost 6,000 ha, however, the AW habitats cover about 2,400 ha. Although we divide this breeding territory into two parts, it is a continuous breeding group occupying the whole territory from the village of Vetly to the mouth of the Tsyr river. The total area of the site UA-14 (south of Pripyar river) is roughly 4,250 hectares; however, not the whole area is suitable for the Aquatic Warbler, because there are large tracts of shrubs, reeds and dry plots. The area of AW habitats is estimated at approximately 1,900 hectares; 1,600-1,650 ha are located in the area between the Prypiat and Tsyr rivers, and 250 ha south from the Tsyr river (mire Musheve). Within this area two monitoring routes have been established. One is 1.5 km long near of the village of Vetly (30 ha) and the second route crosses the central part of AW core area; its length is 4.3 km (86 ha). th In 2017 the route near Vetly was counted on 27 June (Annex 1, Map 5). The water level was significant higher than in other breeding areas (Annex 2, Fig. 5). It is important to note that the water level is practically always optimal for AW here. Only in 2007 the water level fell sharply after the deepening of the river in 2006. Nevertheless, an essential part of the monitoring area was burned (70-80%). The western and eastern parts (together 20 ha) of the monitoring site were mowed by 50-60%. The central part (10 ha) is only 10%. 20 males were recorded. For comparison, in 2016 only 8 males were counted, in 2015 – 21, in 2014 – at least 12 males. th The second monitoring route was surveyed on 29 June (Annex 1, Map 5). The water level in the central part of the site was significantly below the optimum – breeding habitats were almost dry (Annex 2, Fig. 6). Practically all AW habitats (more than 90%) were burned out in the previous winter. During the evening census 115 males were registered on an area of 86 hectares. For comparison, on this plot 98 males were recorded in 2016 (86 ha), 86 males – in 2015 and 94 males in 2014 (on an area of only 40 ha). In addition, during the evening surveys, 18 males were registered on 62 hectares (western part of the territory) and 16 males on 60 ha (mire Musheve) (Annex 1, Map 5). In total, 169 males were counted on 238 ha of the breeding site UA-14. The total AW number is estimated at 1,000-1,100 males (in 2016 – 900- 1000 males, in 2015 – 1200-1300, in 2014 – 1,500-1,600). 12 Unfortunately, we did not visit the breeding territory “UA-15. Upper Prypiat, area between Vetly, Hirky and Liubotyn”. The total area of AW habitat is estimated at more than 500 hectares. In 2016 the number was 150-200 males. This year the conditions for nesting were better than last year (this is noted in all other breeding territories). Therefore, we can assume that the number of birds in the breeding site UA-15 was higher and it can be roughly estimated at 250-300 males.

UA-16. Upper Prypiat, area to west from Hrechishcha and Shlapan (Hrechyshcha-Shlapan). UA-17. Upper Prypiat, area to the north from Liubiaz lake (Lake Liubiaz) These areas of sedge habitat are located to the southwest and the south from the village of Hrechyshcha and to the south-east from the village of Shlapan. We distinguish two groups in this area, although it is undoubtedly an integrated continuous breeding habitat. The total area of AW habitat is more than 300 ha (Annex 1, Map 6). The maximum number of the AW reached 220 males in some years. Evening censuses were carried out in the breeding sites “Hrechyshcha- Shlapan” (20 ha) and “lake Liubiaz” (20 ha). In the first case 6 males were counted and in the second – 10 males. In 2016 only 2 males were recorded in “Hrechyshcha-Shlapan” on an area of 100 ha and no male was registered in “lake Liubiaz” on an area of 50 ha. In 2017 the total number in these two areas is estimated at 90-120 males (in 2016 – only 2-5 males).

UA-19. Upper Prypiat, area near Lake Volianske and canal “Khabaryshche” (Lake Volianske). We know two plots in this AW breeding site - one of them is located on the south-eastern shore of the lake (30 ha), the other in the canal area (more 160 ha) (Annex 1, Map 7). Fot the last time we carried out a survey in 2005. At that time, 70-90 males lived in this breeding site (20-30 males on the plot near the lake and 50- 60 males on the plot near the canal). In 2017 the evening censuses were conducted on two plots (Annex 1, Map 7). 7 males were counted on the plot near the lake and 47 males on the plot south from canal “Khabaryshche”. We estimate the total AW number of the site at 120-150 males.

UA-20. Turiia valley, marsh “Vyzhery” (Vyzhery) The total area of AW habitat is about 275 ha (Annex 1, Map 8). The monitoring route of 1.5 km length passes through the central part of the territory. On the map it is located in the middle. The hydrological conditions at the site were thus optimal for breeding AW (Annex 2, Fig. 7). According to our own observations the habitats were not dry due to natural lowering of the 13 floodplain area. The river increasingly stabilizes the water regime in this breeding territory; if the water level in the river decreases, the water flows very slowly out of the floodplain. The range of water level fluctuations in the monitoring pit during the breeding period was 30 cm for the years of our observations (2002-2017). In 2017 the survey was carried out on area 84 ha (Annex 1, Map 8). The conditions for AW were suboptimal – all mire was dry and more than 60% of breeding site was burned. 18 males were counted on the monitoring plot (30 ha). On the other two plots 34 males were recorded. The total AW number was estimated at 160-180 males (in 2016 – 100-110, in 2015 – 170-190; in 2014 – 30-40).

UA-21. Stokhid valley, area near Sudche (Sudche)

This breeding group is located to the northwest of the village Sudche on the right bank of the floodplain. The area was drained a few decades ago; however, the habitats were quite flooded in the northern part. Now, the major part of the area (central and western plots) is significantly transformed (being overgrown with bushes); however, the zone located along terraces has remained very attractive for AW. The area of the site is more 500 ha. The AW number exceeds 200 males in favourable seasons. th The survey was carried out on 30 June 2017. The water level was optimal – 10-15 cm above the ground. After strong fires in 2015-2016 the vegetation cover has become more suitable for AW (the area of bushes decreased several times). This season the breeding site did not burn. 42 males were counted on area of 60 ha (Annex 1, Map 9). The total AW number for the site was estimated at 280-300 males (in 2016 – only 30-40 males, in 2015 – 40-50).

UA-22. Stokhid valley, area near Berezna Volia (Berezna Volia)

This breeding site is located to the north of the village Berezna Volia. The area occupied by AW is more than 230 hectares (Annex 1, Map 10). th As at site UA-21 the survey was carried out on 30 June 2017. The whole breeding territory was dry and it was completely burned. Evening census was carried out on an area of 15 ha, 7 males were counted. The AW number for the whole site was estimated at 80-100 males in this season (in 2016 – 25-30 males, in 2015 – 30-40).

UA-23. Styr valley, area between Naviz – Kolky (Naviz-Kolky)

This breeding site consists of five habitat plots separated from each other (Annex 1, Map 11). The monitoring route is located in plot 1. Water content of the other four areas depends on the river water level, primarily because they are located next to the river bed. The monitoring territory is located at a distance of more than 1 km from the river. However, the range of water level fluctuations 14 was about 1 m during the breeding season in different years (Annex 2, Fig. 8). The total area of AW habitat is about 400 ha. Evening censuses were carried out on 3 plots: plot 1 (monitoring plot), plot 2 and plot 3. The survey area of each plot was about 40 ha. The water level in the floodplain was very low – more than 20-40 cm below ground (Annex 2, Fig. 8). Plots 1 and 2 were almost completely burned in autumn-spring; plot 3 was burned by 15-20%. Plots 2 and 3 were almost completely mown; plot 1 – only by 10-15%. 12 males were counted on the monitoring plot (in 2016 – 0.). 3 and 4 males were recorded on plots 2 (in 2016 – 0) and 3, respectively. We estimate the total AW number of the site at 50-60 males (in 2016 – 0, in 2015 – 15-20, in 2014 – 15-20) .

UA-24. Lakes Bile and Pisochne (Bile-Pisochne) This population group was discovered in 2004; the number of AW was estimated at 150 males. This territory was thoroughly examined by an AWCT expedition with 19 ornithologists on 12 th June 2005. The total area of AW habitats was estimated at 285 ha. 105 AW males were counted during the bevening census; the total number was estimated at 120-150 males in that year. The AW habitats are sedge marshes (mostly used for hay-mowing) in the lower territory. The water level there is rather stable, being maintained by some big lakes around these marshes. In 2017 the water conditions in AW habitats were also optimal. True, the water level in the marshes was slightly lower than in previous years. th In 2017, the evening census were conducted on 24 June (Annex 1, Map 12). All habitats were optimal for the Aquatic Warbler relating to both, hydrological regime and vegetation (there were no spring fires). Plot “Lake Branets“ (about 110 hectares): 24 males were counted on an area of 22 hectares (in 2016 – 27 males, in 2015 – 26, in 2014 – 27). The total number of AW was estimated at 90-100 males on the whole plot. Plot near the Lake Bile (80 ha): 27 males were counted on an area of 45 ha (in 2016 – 48 males, in 2015 – 33, in 2014 – 48). The total number of birds at the site was estimated at 45-50 males (in 2016 – 70 males, in 2015 – 50-60 males, in 2014 – 70-80). Area to the west and north of Lake Grybne (60 ha): 30 males were recorded on an area of about 45 ha; the total number of birds was estimated at 40-45 males (in 2016 – 40 males, in 2015 – 50-60; in 2014 – 60-70). The territory to the north-east of Lake Ostrivne (45 ha) was not examined. It is usually inhabited by about 10 males. The total number of this AW group is estimated at 185-205 males (in 2016 – 240-250, in 2015 – 230-260; in 2014 – 260-290).

UA-25. Chornohuzka valley, area near Tseperiv and Baiv (Tseperiv- Baiv) This breeding group was discovered in 2004 and its number was estimated at over 100 males. In June 2005, the area was surveyed in detail by the AWCT 15 expedition. The total area of AW habitat was 430 ha (Annex 1, Map 13). 138 males were counted during an evening census on 350 hectares; the total number of birds was estimated at approximately 170 males. Censuses of birds on this territory have been also conducted in 2006 and 2009; this group was estimated at 120-130 males in those seasons. The hydrological conditions for the Aquatic Warbler have been favourable during four surveys of the site. The number of the group was estimated at 70-80 males during the survey in 2012 (there were spring fires in most parts of the site). nd In 2017, the survey was carried out on 2 July by M. Khymyn. The state of AW habitats was in satisfactory condition relating both, hydrological conditions and vegetation. The census was carried out between the villages of Baiv, Tseperiv and Ozdov on an area of 50 ha; 16 males were counted. Considering the total area of AW habitats, we estimate the total number of the AW group at 80-90 males (in 2016 – 100 males, 2015 – 90-100, in 2012 and 2014 – 70-80 males).

Conclusions

In 2017 the most important breeding areas of both population groups of Aquatic Warbler in Ukraine were surveyed. In particular, eight breeding areas th th of the Desna-Dnipro population were visited from 1 till 8 June (including 7 evening censuses). Four persons participated in the survey. Monitoring of the th th Prypiat population groups was performed from 23 June till 2 July, and nine evening censuses were carried out. Four persons participated in the survey also. The censuses covered 865 ha out of 1,180-1,280 ha of suitable habitat in the breeding sites of the Desna-Dnipro population (66-68%). 102 males were recorded there. In the breeding sites of Prypiat population 542 males were recorded on 966 ha. This is about 14-15% of the total area of suitable habitats of the Prypiat population (6,615-6,715 ha).

During the survey of the breeding sites of the Desna-Dnipro population hydrological conditions were not optimal at the most parts. An illustration of the unfavorable hydrological situation is the fact that the river Supii did not flow at all between Svydovets and Yahotyn. Due to artificial structures (sluice, dam), optimal conditions existed only in the breeding sites UA-05 Udai valley “Dorohinka-Monastyryshche”, UA-08 “Horodok” and UA-06 Halka valley “Halka”. However, in the last site AW were not registered. Three breeding sites were completely dry – in the key territory UA-01 Supii valley “Vilne- Berezanka” only 2 males were counted, in UA-07 Perevid valley “Paskivshchyna” – only 1 male, in UA-04 Supii valley “Voronky” – 0. As a result of low water level in the marsh systems a negative impact on the AW sites has been the burning marsh vegetation (for example, in the site UA-07 “Paskivshchyna” tussock burned also). Two breeding territories (Supii valley UA-02 “Bykiv” and UA-03 “Bilotserkivtsi”) had small areas (20-30% of the 16 total area) with more or less optimal water conditions due to a natural decrease in the floodplain of the river. In 2017 in two out of eight breeding sites no AW have been recorded (UA- 04 Supii valley “Voronky” and UA-06 Halka valley “Halka”). In the latter case, the reasons are not clear - the conditions for nesting were optimal. The number of birds declined catastrophically in five breeding sites – Supii valley: UA-01 “Vilne-Berezanka”, UA-02 “Bykiv” and UA-03 “Bilotserkivtsi”, UA-07 Perevid valley “Paskivshchyna”, UA-08 “Horodok”. Only in one territory (UA- 05. Udai valley “Dorohinka-Monastyryshche”) the situation became better than in the previous two years. Since 2014 we note a significant decrease in AW numbers. The total AW number of all the eight surveyed breeding sites of the Desna-Dnipro population was estimated at only 217-275 males (Annex 2, Table). For comparison, in 2016 the AW number was estimated at 153-220 males, in 2015 – 300-375, in 2014 – 450-500.

In 2017 the AW breeding territories of the Prypiat population were surveyed in 15 breeding sites, two of them were visited during daytime (UA-11 Upper Prypiat, area east of the Turiia mouth and UA-29 Stokhid valley, area near St. Chervyshcha). In this season, the hydrological conditions of AW sites of the Prypiat population were similar to those in the breeding territories of the Desna-Dnipro population. For the fourth consecutive year in the Prypiat river basin no spring floods occurred. This often leads to burning of AW habitats. Such situation often happened in 2014-2016. In comparison with these years, in 2017 the percentage of burned habitats was slightly lower. Practically completely burned (before the breeding season) AW habitats have been UA-13 “Nevir-Zalissia”, UA-22 “Berezna Volia”, and UA-23 “Styr valley “Naviz-Kolky”. 60-80% of the AW breeding habitats have been burned in UA-14 “Vetly-Birky” and UA- 20 “Vyzhery”. During our surveys, optimal water conditions for AW were found only in two AW sites (UA-24 lakes Bile and Pisochne and UA-25 Chornohuzka valley “Tseperiv-Baiv”) and on a small part (not more than 10%) of UA-14 “Vetly- Birky”. On all other breeding territories the water level was below the ground. In 2017, compared with last year's season the AW number has increased in almost all the breeding sites. Only in UA-09 “Richytsia-Pidhiria“ the number has not changed, and at UA-24 Lakes Bile and Pisochne and UA-25 Chornohuzka valley “Tseperiv-Baiv” the numbers have slightly decreased. The total AW number of the Prypiat population was estimated at 2,850-3,280 males (Annex 2, Table).

The total AW number in Ukraine in 2017 we estimate at 3,067-3,555 males.

17

Annex 1

Map 1. Results of censuses in the breeding site “UA-05. Udai valley, area between Dorohinka and Monastyryshche”

18

Map 2. Results of censuses in the breeding sites “UA-09. Upper Prypiat, area between Richytsia and Pidhiria” and “UA-10. Upper Prypiat, area between Pidhiria (Shchedrohir) and Turiia mouth”

19

Map 3. Results of censuses in the breeding site “UA-13. Upper Prypiat, area to the south of Nevir (including mire “Zalissia”)”

20

Map 4. Result of the census in the breeding site “UA-11. Upper Prypiat, area to the east from Turiia mouth”

21

Map 5. Results of censuses in the breeding site “UA-14. Upper Prypiat, area between Vetly, Birky and Tsyr”

22

Map 6. Results of censuses in the breeding sites “UA-16. Upper Prypiat, area to west from Hrechishcha and Shlapan” and “UA-17. Upper Prypiat, area to the north from Lake Liubiaz”

23

Map 7. Results of censuses in the breeding site “UA-19. Upper Prypiat, area near Lake Volianske and canal Khabaryshche”

24

Map 8. Results of censuses in the breeding site “UA-20. Turiia valley, marsh ‘Vyzhery’”

25

Map 9. Results of censuses in the breeding site “UA-21. Stokhid valley, area near Sudche”

26

Map 10. Results of censuses in the breeding site “UA-21. Stokhid valley, area near Berezna Volia”

27

Map 11. Results of censuses in the breeding site “UA-23. Styr valley, area between Naviz – Kolky”

28

Map 12. Results of censuses in the breeding site “UA-24. Lakes Bile and Pisochne” 29

Map 13. Results of censuses in the breeding site “UA-25. Chornohuzka valley, area near Tseperiv and Baiv”

30

Annex 2

20

0 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

-20

-40

-60

Water level (cm) -80

-100

-120

Water level Line trend (water level) -140

Fig. 1. Dynamics of water level in the floodplain of the Udai river on the border of the Chernihiv and the Poltava regions (beginning of June)

31

15

10

5

0

2 8 0 1 3 4 7 02 03 06 09 12 1 16 00 0 0 0 00 0 01 0 01 0 01 2 2 2 2005 2 2 2 2 2 2 2 2 y y y y e y e e e ne ne 2004 n u u Ma-5 Ju Ma Ma Ma Jun Ma Jun May June 2015 J Jun I I II II May I I I I June 201I I I І І І II II I III June 2003III May 2004II J I II II June 2007II II II II June 20

Level of water (cm) water of Level -10

-15

-20

Water level Optimum Line trend (Water level)

-25

Fig. 2. Dynamics of water level on the monitoring plot in the key breeding site “UA-01 Vilne-Berezanka”

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290

270

250

230

210 Water level (cm) level Water

190

170

150 1 May 11 May 21 May 1 June 11 June 21 June 1 July 11 July

2014 2015 2016 2017 The going out of water on floodplain

Fig. 3. Dynamics of water level in the Prypiat river on water post Liubiaz in May - June 2014 – 2016 32

80

60

40

20

0 Water level (cm) level Water 4 10 004 016 e 2003 2 e 2005 e 2007 20 e 2012 n n n n ly 201 une June Ju May 2006 Ju June 2009 J Ju Ju June 2 I June-20 2002 I Ju I I I June 2008 I I II I June 2015 I I III III I II III I II III June 2017

-40

Water level Optimum Line trend (water level) -60

Fig. 4. Dynamics of water level on the monitoring plot in the key breeding site “UA-09 Richytsia-Pidhiria”

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60

40

20

0 Water level (cm) level Water 0 2 4 02 03 04 08 15 16 17 007 0 01 01 0 20 2 2 2 2 20 20 e y 2006 e e ly n a u u un une J une une J June 20 June 20 J J June 2009 J J -20 I I I June 2005 I I I June 201 I Jun II II III M II I III II II II III June 2

-40

Water level Optimum Line trend (water level) -60

Fig. 5. Dynamics of water level on the monitoring plot in the key breeding site “UA-14 Vetly-Birky” – near village Vetly (next to river Prypiat) 33

50

40

30

20

10

0 I II III III II III I III I II II III June July June June June June June June June June June June -10 2004 2005 2006 2007 2008 2009 2010 2012 2014 2015 2016 2017 Water level (cm) level Water -20

-30

-40

-50 Water level Optimum

-60

Fig. 6. Dynamics of water level on the monitoring plot in the key breeding site “UA-14 Vetly-Birky” – the area between the Prypiat and Tsyr

25

20

15

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5 Water level (cm) level Water

0

3 6 8 9 0 0 0 0 0 1 14 0 0 0 0 0 2012 0 e 2 2 e 2007 e 2 e 2 e 2 n y n n ly 2 ne 2017 une 2002 u un un u une 2016 u J Ma Ju J I June 2004 I June 2005 I J II J II -5 II Ju III III J II J III III June II June 2015 II III J

-10

Water level Optimum Line trend (water level) Линейный (Water level)

Fig. 7. Dynamics of water level on the monitoring plot in the key breeding site “UA-20 Vyzhery” 34

80

70

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50

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30

20 Water level (cm) level Water 10

0

02 3 07 8 09 4 5 17 005 00 010 012 1 01 2 20 2 2 2 2 20 e 20 e 200 e 2006 e e e 20 e 20 e e 2016 e -10 n ay n n n ay n n u u u Ju J J Ju M J I Jun I Jun I June 2004 I I M I June I I Ju I II III II Jun III ІІ II II Jun I III -20 Water level Optimum Line trend (water level)

-30

Fig. 8. Dynamics of water level on the monitoring plot in the key breeding site “UA- 23. Styr valley”

35

Table. Results of monitoring of AW breeding groups in Ukraine in 2014-2017

Code of Full name of Area of Estima- Estima- Estima- Area of Number Estima- subsite subsite the site tional tional tional census in of males, tional in ha number number number 2017 counted number in 2014 in 2015 in 2016 in 2017 in 2017 UA-01 Supii valley, area 260 70-80 70-80 15-20 260 2 2 between Vilne and (suitable) M.Berezanka UA-02 Supii valley, area 50 12-15 8-10 14-15 50 2 2 near Novii Bykiv (suitable) UA-03 Supii valley, area 100 3-5 25-30 20-30 100 7 7-10 near Bilotserkivtsi (suitable) UA-04 Supii valley, area 60 10-12 0 0 60 0 0 near Voronky (suitable) UA-05 Udai valley, area 500-600 300-320 150-200 100-150 185 85 200-250 between Dorohinka (suitable) and Monastyryshche UA-06 Halka valley, area 120 20-25 8-10 4-5 120 0 0 between (suitable) Bohdanivka and Leonidivka UA-07 Perevid valley, area 50 15-20 15-20 ? 50 1 1 near Paskivshchyna (suitable)

UA-08 Mire near Petrivka 40 23-25 23-25 ? 40 5 5-10 (zakaznik (suitable) “Horodok”) Desna-Dnipro population 1180-1280 450-500 300-375 153-220 865 102 217-275

UA-09 Upper Prypiat, area 250 15-20 150-180 130-150 70 38 130-150 between Richytsia (suitable) and Pidhiria (Shchedrohir) UA-10 Upper Prypiat, area 175 5-10 70-80 60 10 12 80-100 between Pidhiria (suitable) (Shchedrohir) and Turiia mouth UA-11 Upper Prypiat, area 90 60-80 60-80 ? 10 6 60-80 to east from Turiia (suitable) daytime mouth UA-12 Upper Prypiat, area 350 80-90 80-90 ? 50-60 to east from canal (suitable) Vyzhevskii UA-13 Upper Prypiat, area 600 150-200 150-200 120-150 55 23 150-200 to the south of (suitable) 20 7 Nevir (including (daytime) (daytime) mire “Zalissia”)

36 Code of Full name of Area of Estima- Estima- Estima- Area of Number Estima- subsite subsite the site tional tional tional census in of males, tional in ha number number number 2017 counted number in 2014 in 2015 in 2016 in 2017 in 2017 UA-14 Upper Prypiat, area 1900 1500- 1200- 900- 238 169 1000- between Vetly, (suitable) 1600 1300 1000 1100 Birky and Tsyr UA-15 Upper Prypiat, area 500 250-300 500 150-200 250-300 between Vetly, (suitable) Hirky and Liubotyn

UA-16 Upper Prypiat, area 250 80-100 50-60 2-5 20 6 70-90 to west from (suitable) Grechishcha and Shlapan UA-17 Upper Prypiat, area 50 30-35 15-20 0 20 10 20-30 to north from (suitable) Liubiaz lake UA-18 Upper Prypiat, area 40 30 30 ? 30 near lake Rohozne (suitable) UA-19 Upper Prypiat, area 200 80 80 ? 70 54 120-150 near Volianske lake (suitable) and canal “Khabaryshche” UA-20 Turiia valley, mire 275 30-40 170-190 100-110 84 52 160-180 “Vyzhery” (suitable) UA-21 Stokhid valley, area 500 100-120 40-50 30-40 60 42 280-300 near Sudche (suitable) UA-22 Stokhid valley, area 230 50-60 30-40 25-30 20 7 80-100 near Berezna Volia (suitable) UA-23 Styr valley, area 400 15-20 15-20 0 120 19 50-60 between Naviz and (suitable) Kolky UA-24 Lakes Bile and 285 260-290 230-260 240-250 112 81 185-205 Pisochne (suitable) UA-25 Chornohuzka 430 70-80 90-100 100 50 16 80-90 valley, area near (suitable) Tseperiv and Baiv UA-26 Shatski lakes, mire 100 25 25 ? 25 "Unichy" (suitable) UA-27 Upper Prypiat, lake 10 10 10 10 Nobel (suitable) UA-28 Mire near 10 10 10 ? Perebrody (suitable) UA-29 Stokhid valley, area 20 0 0 0 5 0 0 near (suitable) (daytime) St.Chervyshche UA-30 Mire near Stare 30 20 20 ? Selo (suitable) UA-31 Upper Prypiat, area 20 20 20 20 near Senchytsi (suitable) Prypiat 6,715 2,890- 3,045- 1,857- 964 542 2,850- population 3,250 3,365 2,095 3,280

37 Code of Full name of Area of Estima- Estima- Estima- Area of Number Estima- subsite subsite site tional tional tional census in of males, tional number number number 2017 counted number in 2014 in 2015 in 2016 in 2017 in 2017 TOTAL 7,895- 3,340- 3,345- 2,010- 1,829 644 3,067- 7,995 3,750 3,740 2,315 3,555