African-Eurasian :Flyways A census of migrating waders in Bulgaria 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 Burgas, 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 Blagoevgrad, Sokolitsa, Trud, Nikolaevo, and Yambol, 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 Black Sea 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 (Sofia) 2. Fish pondsBlagoevgrad 3. Artificial lake Gorni Dabnik 4. Fish pondsSokoliza (Karlovo) 5. Artificiallake Pjasacnik 6. Fish pondsTrud (Plovdiv) 7. Rice-fields Belozem 8. Fish pondsNikolaevo (Sliven) 9. Fish pondsJambol 10. Place Poda (Burgas) 11. Lake Atanasov(Atanassovsko ezero) 12. Lake Pomorie(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