African-Eurasian :Flyways

A census of migrating waders in during March-May 1990

Dimitar Nankinov, Kalina Tsvetkova, Kiril Bedev, Georgi Lamburov, Nikolai Minchev, Valentin Bozhilov, Simeon Marin, Georgi Seizov & Geigi Kotsakov

Nankinov, D., Tsvetkova, K., Bedev, K., Lamburov, (3., Minchev, N., Bozhilov, V., Marin, S, Seizov, (3., & Kotsakov, (3. 1996. A census of migratingwaders in Bulgaria during March-May 1990. Wader Study Group Bull. 83: 37-43. A censuswas conductedat 14 principalareas for migratorywaders in Bulgaria. A total of 32 wader species were observed, representing40,802 individuals. The migration was at its maximum at the end of March and early April with 38% of records. Another migration wave occurredduring the second half of May. The greatest numbers of migrants were Ruffs Philomachuspugnax, which comprised35% of total wader numbers, followed by Curlew Sandpiper Calidrisferruginea (17.7%), and then Avocet Recurvirostra avosetta (11%). The Pomoriiskoand Atanassovskoezero (lake), where respectivelyon average 3,487 and 1,733 waders stopover, are of primary importance for the spring migration of waders in Bulgaria.

INTRODUCTION AND METHODS Pomoriiskoezero, Durankulak), the Poda marshland near , the steppe sites at Cape Kaliakra, as well as A census of migratingwaders in Bulgaria was conducted inland reservoirs at the fisheries at Chelopechene, in March-May 1990 in connection with an international , Sokolitsa, Trud, , and , the projectto study waders on their migration routes between artificial lakes at Gorni Dabnik and Pysachnik and the rice Africanwintering sites and nesting sites. In the course of fields at Belozem. For a number of reasons,among them the censuswe tried to includethe main areas in Bulgaria politicaltension in the country and lack of funds, the plan where waders converge (Figure 1 ), above all the lakes as originallyenvisaged was not fully realised. The census along the Bulgarian coast (Atanassovsko ezero, was conducted at weekends as most of the participants were not available on weekdays.

Figure1. The sitesfor censusingof wadersin Bulgaria(March-May 1990)

1, Fish pondsTschelopetschene () 2. Fish pondsBlagoevgrad 3. Artificial lake Gorni Dabnik 4. Fish pondsSokoliza () 5. Artificiallake Pjasacnik 6. Fish pondsTrud () 7. Rice-fields Belozem 8. Fish pondsNikolaevo () 9. Fish pondsJambol 10. Place Poda (Burgas) 11. Lake Atanasov(Atanassovsko ezero) 12. Lake (Pomoriisko ezero) 13. Cape Kaliakra 14. Lake Durankulak

37 Stone Curlew Burhinus oedicnernus RESULTS One pair each was observed on the traditionalnesting Over the perioda total of 32 speciesof waders were groundsof the Stone Curlew around Cape Kaliakra, off recorded at 14 sites (Table 1). Observations of interest Blagoevgradand the Atanassovskoezero. There has are summarised by species below. been a trend for Stone Curlews to breed on farmland. Currentlythe populationin Bulgariaexceeds 100 pairs. Oystercatcher Haemantopus ostralegus Collared Pratincole Glareola pratincola Separate birds or flockswere observedaround the fisheries at Chelopechene, Sokolitsa, Trud, in the Belozem The Collared Pratincolewas observedat only two sites: rice-fields,the Poda locality and above all Atanassovsko the fisheriesat Sokolitsa (1-4 pairs) and the Atanassovsko ezero and Pomoriiskoezero. Sightingsat the end of April ezero (6-13 pairs). The first migrantsappeared on 22 and in May were of nesting pairs: one pair on the rice- April. fields of Belozem, Poda and Pomoriisko ezero and two pairs in Atanassovskoezero. Two youngwere found in Black-wingedPratincole Glareola nordmanni the Atanassovskoezero on 24 May. Two specimensof this rare European bird were observed Black-wingedStilt Himantopus himantopus at the Atanassovsko ezero, where we suppose it nests.

Most birdswere observed in the main nestingareas of this Lapwing Vanellus vanellus species:Atanassovsko ezero - about 60 pairs, Pomoriisko ezero- 35 pairs, Poda marshes - 14 pairs, and Lapwingsare one of the commonestwaders migrating DurankulakLake - 2 pairs. We think that the species was throughBulgaria. They were absent from all biotopes nestingin the Sokolitsafisheries (one pair) and the included in the census and their vicinity. Hundreds of Yambol fisheries(two pairs) The migrationof Black- specimensconverged in the fisheries of Sokolnitsa,the winged Stilt was late in 1990. The first sightingswere on Pyasachnik artificial lake, and the Atanassovskoezero. 8 April, while most birds arrived at the end of the month. As an early migrant, its migration generallyends in March and early April (Figure 3). The first hatchedyoung in the Avocet Recurvirostra avosetta fisheries •n Sokolitsa were observed on 22 May.

Avocetswere observedonly in East Bulgaria(Figure 2) and in the main nesting areas - the Pomoriiskoezero and

Atanassovskoezero, where respectively100 and 125 600 pairs nested. In March and April, between300 and 400 pairs assembledthere during migration. Avocets also nested at the Poda marshes (one pair), DurankulakLake (two pairs), and possibly in the Yambol fisheries (one oair). Six pairs had nests with eggs by 22 April. z 2oo

lOO

600 o

5C

Date _E3c z 2c Figure3 The variationin numbersof Lapwingthroughout the la census period

Grey Plover Pluvialis squatarola

The greatestnumber (up to 11 specimens)were observed Date on Atanassovskoezero. Only five were observedin the fisheries of Trud.

Figure2 Thevariation in r•umbersof Avocetthroughout the census period

38 Ringed Plover Charadrius hiaficula Trud fisheries (80 birds), the Pomoriisko ezero (35 pairs), and fisheries at Chelopechene(10 birds). To our surprisethe Ringed Plover was observed only in the interiorof the country(between 29 April and 27 May), in the Sokolitsafisheries (two specimens) and Yambol (1- 250 9 specimens). No migrationwas observed along the Black Sea coast. 200 Little Ringed Plover Charadrius dubius

The Little Ringed Plover migrated all over the country Z 100 although in small numbers only. Usually no more than a few tens of birds were seen at water bodies: at the Atanassovskoezero up to 26, at Sokolitsa 22 and at Chelopechene up to 10.

Kentish Plover Charadrius alexandrinus

o o •- •- •- •_ • Unlikethe precedingspecies, the migrationof Kentish Date Plover followedonly the Black Sea coast. It was observed in the three biotopesoff Burgas (Poda, Atanassovsko ezero, and Pomoriiskoezero). The spring migration Figure4 The variationin numbersof SpottedRedshank throughout began at the end of March (25 March), with the largest the census period numbers convergingin the Pomoriisko ezero (120 pairs). About 40 pairs remained and nested in the Atanassovsko Redshank Tringa totanus ezero. On 22 April, four nests with three eggs each, one nest with one egg, and seven empty nests were observed. The Redshank occurred in similar numbers to the Spotted Redshank, however it was sighted on a smaller number of Black-tailed Godwit Limosa limosa biotopes. Numbers at the Atanassovskoezero reached up to 500 daily, and up to 60 occurred on Pomoriiskoezero. These were observed at nine of the sites. The census Migration occurred over a much shorter period - between periodcovered the second half of its spring migration- 12 March and 8 April (Figure 5). which ends in early April. Black-tailedGodwits converged on the Pomoriiskoezero (up to 135 birds), Atanassovsko ezero (45 birds),the fisheriesat Chelopechene(33 birds),

Sokolitsa (18 birds), Nikolaevo (10 birds). By mid-March 600 m•grating birds had moulted and had winter plumage. During the second half of March individual birds were 500 seen in winter plumage as well as in breedingplumage; after that they were only seen in breeding plumage. A bird 400 in breeding plumage was also observed on 6 May at Durankulak Lake - one of the presumed nesting sites of the species in Bulgaria.

Curlew Numenius arquata 100

The Curlew was observed throughoutthe whole period at the Atanassovskoezero; at first in flocks of up to 26 and duringthe second half of April and May as separate birds and pairs. The greatest numberthat convergedat the end Date of March at the Pomoriiskoezero was 62 pairs. At inland water bodies the Curlew was observed in Blagoevgrad and Sokolitsa. Figure5 The variationin numbersof Redshankthroughout the census period Spotted Redshank Tringa erythropus Marsh Sandpiper Tringa stagnat#is This is one of the numerousspecies of waders sighted duringthe observationperiod all over Bulgaria. The main The main springmigration passed throughthe wave of migrantspassed through early in March and on Atanassovskoezero, where up to 300 young Marsh 22 April (Figure4). The SpottedRedshank was a regular Sandpiperswere recorded. Individualadults and young visitorin great numbersto Atanassovskoezero, where up also stoppedat the fisheriesat Chelopechene, to 200 pairs came daily. The birdsalso convergedon the Blagoevgrad,Sokolitsa and Trud. Marsh Sandpiperswere

39 sighted between4 March and 13 May, howeverthe main Snipe Gallinago gallinago spring migrationwas in April. Snipe were found regularly, most often in two biotopes: Greenshank Tringa nebularia the fisheries of Sokolitsa (in flocks of up to 33) and at Atanassovsko ezero (up to 13 birds). The spring The Greenshank occurs in small numbers, although it is migration ended early in May, however a pair remained in more abundant in Western and Central Bulgaria than in the Poda marshes on 27 May. the eastern part. The greatest numbers during one census were seen at the Chelopechene fisheries (20), Jack Snipe Lymnocryptesminima Nikolaevo(20), and Sokolitsa (16). The migration occurred over three months - from early March to the end Up to 5 of these birdswere observed in south-west of May. Bulgaria •n the fisheries at Blagoevgrad between 4 March and 1 April. Green Sandpiper Tringa ochropus Sanderling Calidris alba The Green Sandpiper was more numerous in the western half of Bulgaria in March and early April, while in the A total of nine Sanderlingwere seen (three birds together eastern part greatest numbers were seen in April and plus another six birds) in the Pomoriisko ezero on 27 April early May. At the Atanassovskoezero the spring and 27 May. No other Sanderling were observed. migration of Green Sandpiper occurred between 25 March and 13 May (maximum numbers occurringbetween 8 Little Stint Calidris minuta April and 6 May), with up to 120 birds counteddaily. Smaller numbers were observed at the fisheries at Yambol (90), Nikolaevo(30) and Sokolitsa(12). Although separate birds were seen in March, the main migrationbegan in mid-Apriland increased•n s•ze until the end of the observation period (Figure 6). The largest Wood Sandpiper Tringa glareola number of birds recorded together at one site (Atanassovskoezero) exceeded 1,000. There were far The spring migrationof the Wood Sandpiper in 1990 fewer in the Pomoriiskoezero (up to 150 birds), the rice- began after 16 March. The migration was on a more fields of Belozem (140) and Durankulak Lake (up to 100). massivescale duringthe second half of April and early Elsewhere no more than several tens of Little Stint were May. Larger numbers converged in the fisheries of noted. Sokolitsa(up to 121 birds), Trud (106), Atanassovsko ezero (70), Poda marshes (38), the Yambol fisheries(35) and Chelopechene (25).

Common Sandpiper Actitis hypoleucos 12OO

Several clear waves of migration were observed in the lOOO during spring (early March and mid April), and along the river and Black Sea coast 800 (from 22 April to 20 May). At Atanassovsko ezero, the 600 Yambol fisheries and at Trud, flocks of between 24 to 36 birdsgathered for several days. In the remainingbiotopes 400 several Common Sandpiperswere counted. 200 Tu mstone Arenaria interpres o

Turnstoneswere observed only along the Black Sea coast (Atanassovskoezero, Pomoriiskoezero), numbering between one and nine birds, between 25 March to 27 May. Date

Woodcock Scolopax rusticola

Figure6 The variationin numbersof LittleStint throughout the A speciesappearing in small numbersduring the spring studyperiod migration. One was observedon 2 March and 25 March near Blagoevgrad. Temminck's Stint Calidris temminckii

Great Snipe Gallinago media This specieswas observedat water bodiesin western Bulgaria,the fisheriesat Chelopechene(up to 20 birds This specieswas observed rarely (one to four birds in a daily) and Blagoevgrad(individual birds). biotope)either inland or along the Black Sea coast.

40 Dunlin Calidris alpina

Springmigration of this speciesin 1990 was early in Marchand the observationperiod included only the end of 12OOO the migrationperiod. At the Atanassovskoezero and Pomoriiskoezero, 152 and 400 birds respectivelywere recorded. 80OO

Curlew Sandpiper Calidris ferruginea

The CurlewSandpiper occurred in large numbers. Its migrationbegan after 16 Marchand increaseduntil the end of May (Figure 7) when up to 2,500 birds gatheredat the Atanassovsko ezero. Flocks at Pomoriisko ezero (250 birds), Belozem (170), and Durankulak (80) were one tenth the size. Curlew Sandpipermigrated across south- east and east Bulgaria. Date

3OO0

25OO Figure8 The variationin numbersof Ruff throughoutthe census period

200O Concentrations of Ruffs on the Pomoriisko ezero of up to 8,600 birds, at Atanassovsko ezero of 600 birds, at Sokolitsa fisheries of 132 birds and at Durankulak !00 birds were recorded. After 25 March, breeding plumage appearedaround the neck.

Over the survey period(4 March to 27 May) a total of 40,802 waders were observed and recorded. The variation in their numbers is shown •n Figure 4. Two principalmigration waves duringthe springmigration can Date be seen. The main one is at the end of March and early April,when 37.7% of the birdspassed through; the other duringthe second half of May (19.8%). A minor wave Figure7 The variationin numbersof Cur•ewSandpiper throughout occurs between these two waves, i.e. in the last days of the censusperiod April (12.5%). The ?:ighestnumbers of migratingwaders in spring1990 were Ruffs (35% of the total), followedby Broad-billed Sandpiper Limicola falcinellus CurlewSandpiper (17.7%), Avocet(11%), LittleStint (9.4%), Lapwing(3.7%), Redshank(3.6%) and Spotted A rare species. Two birds were observedfairly early, on Redshank (3.5%). 11 March at the fisheries of Blagoevgrad. Usually the springmigration of the Broad-billedSandpiper follows the The Pomoriisko ezero and Atanassovsko ezero, with an Black Sea coast as well as coming later - from April to average of 3,487 and 1,733 birds daily respectively,are June. the most importantof the sites censusedfor migrating wadersin spring. These lakes,which are also salt works, Ruff Philomachuspugnax have been cut off by dykes. During the observation periodlarge numbersof insectlarvae occurred- abundant The migrationof this highly numerouswader takes place food for waders - in some of the dykes. Of the inland overan extendedperiod. The maximumnumbers of birds reservoirs,the fisheries at Sokolitsa, inhabiteddaily by cross in a broad front for a very short period in the second 125 birds,are importantto waders. The importantrole of half of March (Figure 8). A minorwave of migration fisheriesin Bulgariafor the migration,wintering and occurs a month later - towards the end of April. nestingof waders shouldbe noted. Most of the fisheries have been establishedin marshlands, i.e. along traditional migrationroutes of birdsand the timingof the drainingof the basins of fisheries coincideswith wader migration. This is the time when many waders convergein drained basins with a silt covered bottom, or with a minimal water level.

41 Over the period of observation no dye-marked birds were ACKNOWLEDGEMENTS seen. No waders were caught and ringed, or studied in any other way, due to a shortage of nets. The authors wish to thank Toni Tonev, Antonia Batschvarova, Petko Cvetkov, Vera Aleksandrova, Dimitar Velev, Emilia Kuntscheva, Ivailo Zafirov, Andrei Dimitrov, Ivan Jeljaskov, Katerina Zareva, KonstantinBozhilov, Maria Vasileva, Maria Jeljaskova, Ognian Gadularov, Petar Tentschev, Semela Dukova, Christo Ivanov, who all helped in censusingof waders in Bulgaria during March to May 1990.

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