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Wader migration in Babushkina Bay, Russian Far East, June - August 1995

Axel Degen,Achim Hergenhahn & Helmut Kruckenberg Degen,A., Hergenhahn,A. & Kmckenberg,H. 1998. Wadermigration in BabushkinaBay, RussianFar East,June - August 1995. WaderStudy Group Bull. 85: 75-79.

Wadercounts were cardedout from mid-Juneto mid-August1995 duringan internationalexpedition to BabushkinaBay, RussianFar East. The mostnumerous species were Red-necked Phalarope Phalaropus lobams (5,000), Red-neckedStint Calidris ruficollis (1,000), Dunlin Calidris alpina (150), LesserSand Plover Charadriusmongolus (70) andTerek SandpiperXenus cinereus (55). Possibleprey speciesin the tidal sandflatsincluded annelids and crustaceans.

A. Degen, Tannenburgstr.11, D-49084 Osnabrueck,Germany; A. Hergenhahn,Wilhelm-von-Euch-Str. 52, D49090 Osnabrueck, Germany;H. Kruckenberg,Faldernstr. 31, D-26725 Emden,Germany.

INTRODUCTION The North Pacificregion represents a relatively small portion East$iberia•• Bering of the holarctic landmass, but it is one of the world's most importantbreeding areas for shorebirds(Gill et al. 1995). At least67 migratingspecies or subspeciesoccur in the Russian Far East. The Seaof Okhotskis the mostimportant region for migrantwaders in the RussianFar Eastduring southward passage.However, chronology of migrationof sexesand ages in most of the speciesis poorly understood,and only a preliminaryinventory of wetlandsof importancefor waders ! Ohot, was only carded out recentlyfor the RussianFar East (Tomkovich1996). Thereforeone of the workinggroups of an ; internationalexpedition to BabushkinaBay, RussianFar East, focusedon the migrationof shorebirds.The expedition consisted of teams from the Eastern Palearctic Wetland Magadan, ResearchCentre, Magadan, Russia, and the Universityof Osnabrueck,Germany.

STUDY AREA The studyarea was situatedin the BabushkinaBay (59ø13' N; 153027' E), 150 km eastof Magadan(Figure 1). It covered swampyas well as rocky coastaltundra surrounding a lagoon. / •ea• This uniquetundra belt extendedup to 3 km inland. Pine Pinus pumila and alderAlnusfruticosa underbrush mark the transitionto hills and mountains.The lagoonwas separated from the opensea by a long and narrowspit exceptat the south-westernend. Wide sandand gravelbanks lay between the threelagoon supplying rivers 0VieIdek,Srednjaja and Buksendja).At low tide, sandytidal flats in the lagoon emergedfrom the water. In mid-Junethe tidal flats were totally ice-covered;the last ice thawedin July. Usually higher high tides(average tidal range2.5 m) alternatedwith lower high tides(average tidal range0.2 m). The lower high tides normallydid not even coverthe tidal flats. The spit and the tidal flats appearedto be the mostimportant staging areas for waders.

METHODS 2km Groundcounts of waders,especially on the tidal flats (1 km2) and the shoresof the spit (9 km), were madeat leastonce per five-day periodover 63 daysfrom 14 Juneto 15 August. The last regularcount on the tidal flats took placeon 13 Augustand Babushklna Bay on the spit on 11 August. Someadditional observations near Figure 1. Locationof the studyarea in BabushkinaBay 77 the campwere made later. On 10 and 12 August, 15 soil Little Curlew Numenius minutus sampleswere takento find out possibleprey specieson the No stagingbirds were observed.Migrating groupsseen were 6 tidal flats. A rigid plastictube was insertedinto the water and individualson 21 July, 12 individualson 9 August,85 pushedthrough the substrate.The substratewithin the tube individualson 10 Augustand 134 individualson 12 August. was stirredand the invertebrateswere removedusing a fine sieve. The processwas continueduntil no moreitems were WhimbrelNumenius phaeopus found. The invertebrates were stored in 70 % alcohol for The first Whimbrelwas seenon 27 July on the tidal flats. Up identificationlater. The densityof individualswas not to 8 Augustonly individualsor smallgroups with a maximum recorded. of four birdswere recorded.In the week from 9 - 15 August, the numberof passingand roostingbirds increased with a SPECIES ACCOUNTS maximumof 238 migratingand 40 roostingbirds seen on 10 Pacific GoldenPlover Pluvialisfulva August. Small groupswith a maximumof 23 (10 August)were seen from 9 July to 12 August. The birdsappeared mainly in the Far Eastern Curlew Numeniusmadagascariensis tundra. From mid-Juneup to the end of July singleindividuals or pairs were seenat irregularintervals. A breedingpair was locatedin Grey (Black-bellied)Plover Pluvialissquatarola thepeat marshes of the Srednjajavalley. Threeadults were seenroosting on the spiton 19 July. SpottedRedshank Tringa erythropus LesserSand Plover Charadriusmongolus A groupof five individualswas on the spiton 11 July and one The first peakof birdswas observedfrom early to mid July singlebird was observedbetween Srednjaja and Buksendjaon with a maximumof 46 on 12 July. Unfortunately,there is no 14 July. informationabout the age or sex of thesebirds. Between 13 July and8 Augustonly individualsor smallgroups of up to 12 GreenshankTringa nebularia were counted.From 9 Augustonwards, bigger flocks appeared Throughoutthe whole observationperiod, single birds and in the studyarea, with a maximumof 70 birdson 10 August. smallgroups (a maximumof 13 birdson 10 August)occurred Most birdswere malesand juveniles, and only very few irregularlyin the studyarea. The firstjuvenile birdswere seen femaleswere seen(Figure 2). The birdsoccurred mainly on on 8 August. the spitor in the tidal flats. Green SandpiperTringa ochropus Two individuals were observed in different locations at the 70 deltaof the Meldek river on 31 July and anotherat Buksendja on 1 August. 60 Djuvenites

SO WoodSandpiper Tringa glareola liraales ! From 3 Augustonwards, single birds and small groups were

4o seenin all partsof the studyarea. On 4 August,a maximum of 58 birdswas counted.Most birdsstayed near shallow 3O freshwaterpools or riversin the marsharea.

2O Terek SandpiperXenus cinereus The first bird was seenon 3 July and the maximumof 55 was 10 countedon 11 July. Until the end of the observationperiod, individualsand groups of up to 47 birdsappeared mainly on 0 the gravelbeaches of the spit.The dynamicsof migrationare June July August shownin Figure 3.

Figure 2. Dynamicsof migrationof LesserSand Plover Charadrius mongolus 60 in BabushkinaBay 1995 (maximumper five-dayperiod)

Black-tailed Godwit Limosa limosa One adultwas seenon 1 Augustand four juveniles on 10 and 12 August,all birdswere on the tidal flats.

30 Bar-tailed Godwit Limosalapponica Two individualswere seenat the lagoonand at Buksendjaon 25 and26 July. Furtherbirds appeared irregularly from the endof July to 13 August,with a maximumof 23 on 12 August. 10 The firstjuveniles were seenon 10 August.Usually the birds stayedon the tidal flats. From 10 Augustonwards, only June July Augu• juvenileswere observed. Figure 3. Dynamicsof migrationof TerekSandpiper Xenus cinereus in Babushkina Bay 1995 (maximumper five-dayperiod) 78

CommonSandpiper Actiris hypoleucos Very smallgroups or singlebirds were observedfrom 17 July to 10 Augustwith the maximumcount (11) on 26 July. The •juvenile firstjuvenile was seenon 2 August.

Grey-tailed Tattler Heteroscelusbrevipes From 10 July onwards,Grey-tailed Tattiers appeared in the studyarea. Singleindividuals and groups up to a maximumof 29 (8 August)were countedmainly in the saltmarshes.

Ruddy TurnstoneArenaria interpres Scatteredindividuals or groupsup to threewere observed mostlyon the stoneybeaches of the spitfrom 12 to 27 July.

Red-neckedPhalarope Phalaropuslobatus This wasthe mostnumerous shorebird in BabushkinaBay. June August Birdsforaged primarily on the surfaceof the OkhotskSea. Figure 4. Dynamicsof migrationof Red-neckedStint Calidris ruficollis in About 1,000 adultbirds were observedfrom 8 to 12 July on the BabushkinaBay 1995 (maximum per five-day period). opensea outside Babushkina Bay. On 2 Augustthe first Temmincks Stint Calidris temminckii juvenile birdswere seenand, on 5 August,about 5000 Very smallnumbers were seenfrom 2 to 12 August. On 10 juvenileswere feeding in the nearshoreareas, where floating August,a maximumof sevenbirds was observedfeeding in the planktonconcentrated on the surface.On 15August, 650 tidal flats andthe delta of the Srednjaja.The firstjuvenile bird juvenileswere againclose to the shore. In Augustsmall flocks was seenon 8 August. alsoforaged on the lagoonand the tidal flats. Breedingbirds were seenin the freshwatermarshes around Babushkina Bay. Long-toedStint Calidris subminuta Overthe wholeperiod, Long-toed Stints occurred as single Pintail Snipe Gallinago stenura birdsor in scatteredgroups (up to eightindividuals on 8 Four birdswere found scatteredin the densegrass of the spit August)on the marshyedges in the northernparts of the from 5 to 13 August. lagoon. Somebreeding pairs were alsofound in this area.

Red Knot Calidris canutus Bairds' SandpiperCalidris bairdii Singlebirds were seenfrom mid-Julyto mid-August.On 1 One adultin breedingplumage was seen on 31 Julyin the August,up to 22 individualswere feeding on thetidal flats. Meldek delta. The firstjuvenile bird wasseen on 8 August. Sharp-tailedSandpiper Calidris acuminata Great Knot Calidris tenuirostris Two singlejuvenile individualswere seenon 9 and 10 August Small groups(up to 19 on 10 July) were seenfrom 16 Juneto in densevegetation on the spit andin the saltmarshes. 12 Augustmostly on the spit and the tidal flats. The first juvenilebird wasseen on 31 July. Oneflock of four wasfound Dunlin Calidris alpina at a heightof 100 m in a rockyarea with scrubpine trees Pinus The maximumnumber of 117 adultsand 33 juvenileswas pumila on 11 August. On 21 July,200 Great Knotswere seen countedon 8 Auguston the tidal flats (Figure5). The first flying alongthe coastlineto the west. juvenileswere seenon the tidal flats on 27 July,and their numberincreased to mid-Augustwith up to 71 seenon 13 Calidris alba Sanderling August. Breedingbirds were foundin wet grasslandaround There were four recordsof singleadult birds on the spit the lagoon. Thesebirds belong to the subspecies C. a. between 13 July and 3 August. 160

Red-neckedStint Calidris ruficollis This was the mostnumerous wader specieson the tidal flats, with a maximumof at least 1,000 individualson 12 August (Figure4). Larger numbersof adultRed-necked Stints arrived lO0 in late July (up to 195 on 27 July), whereasjuveniles did not occuruntil 3 August. On 12 August,juveniles formed 96% of the total.

40 Little Stint Calidris minuta From 11 to 13 July three adult Little Stintswere observedon the spit and on 14 July, one adult on the shorenear the tidal o flats. ,June July August Figure 5. Dynamicsof migrationof Dulin Calidris alpina in the Babushkma Bay 1995 (maximumfive-day period). 79

kistchinski(Tomkovich 1986; Gill et al. 1995). ACKNOWLEDGEMENTS The expeditioncould only havebeen carded out with the Broad-billed SandpiperLimicola falcinellus collaborationof manypeople. We are gratefulto A.V. Andreev, One adultBroad-billed Sandpiper was observed at the tidal H.-H. Bergmann,W. Gatter,H.-J. Hehman,L. von der Heyde, flats feedingwith Dunlinson 27 July. A.V. Kondratyev,T. Meinrenken,F. Mllers andB. Rupprecht for theirhelp andobservations, B. Saurfor helpingwith the SOIL SAMPLES soil samples,K. Regel for the identificationof invertebrates The invertebratefauna of the soil sampleswas dominatedby and P.S.Tornkovich for editingthe manuscript. crustaceansof many species.The possibleprey speciesfound in the samplesare listedin Table 1. REFERENCES Gill, R.E., Jr., Butler, R.W., Tomkovich, P.S., Mundkur, T. & Handel, C.M. Plathelminthes 1995. Conservationof North Pacificshorebirds. Wader Study Group Bull. 77: 82-91. Turbellaria Annelida Kistchinski,A.A. 1968.Birds of KolymskyHighlands. Moscow. (In Russian) Polychaeta Tomkovich,P.S. 1986. Geographicalvariability of the dunlinin the Far East. Spionidae Biol. Mosk.o-va. ispit.prir. otd. biol. 91: 3-15. (In Russianwith English Nerine sp. (cf. cirratulus) summary). Arenicolidae Tomkovich,P.S. 1996.Main concentrationsof migratoryshorebirds in the Abarenicolasp. (cf. claparedii) RussianFar East, and their conservation.In: Wells, D.R. & Mundkur, T. (Eds.).' Crustacea Conservationof migratorywaterbirds and their wetlandhabitats in the East Asian-AustralasianFlyway. Proc. Internat. Workshop, Kushiro, Japan: 43-62. Ostracoda Copepoda Malacostraca Lampropidae Lampropssp. (cf. beringi) Gammaridae Anisogammarus(Eogammarus) aestuariorum A. (E.) tiuschovi Lagunogammarussetosus Talitridae Allorchestes moskvitini Mysidae Archaemysissp. (cf. grebnitzkii)

Table 1 Possibleprey speciesfor wadersin the tidal flatsof BabushkinaBay.

DISCUSSION BabushkinaBay is alreadyknown as a wetlandof some importancefor migratorywaders based on the observationsof Kistchinski(1968) but Black-tailedGodwit, Sandefiing,Little Stint,Baird's Sandpiper and Sharp-tailed Sandpiper are not on his list for the MagadanRegion. However,the CommonSnipe Gallinagogallinago was not foundin this studyalthough this specieshas a broadbreeding distribution in the Magadan Region(Tornkovich, pers. comm.).

The studyarea seemsto be importantonly for Red-necked Phalarope(foraging on the sea),while the wadersin the lagoon stoppedvery briefly andit is possiblethat many speciesdid not stopat all. A probablereason is the sandysubstrate of the tidal flats and the low densityof annelids. Most high wader concentrations in the Sea of Okhotsk are on mudflats (Tornkovich,pers. comm.).