Butlev& Lebedeva:Curlew Numerous arquata in the Vologdaregion of north-EuropeanRussia

Curlew Numeniusarquata in the Vologda region of north-EuropeanRussia V.T. Butiev & E.A. Lebedeva

Butiev,V.T. & Lebedeva,E.A. 1998. CurlewNumenius arquata in the Vologdaregion of north- EuropeanRussia. International Wader Studies 10: 299-302.

Analysisof data on distributionand someaspects of the breedingbiology of Curlew Numenius arquata,collected in 1970-1993in variousparts of theVologda region (145,700 km 2 of north- EuropeanRussia) has revealed that, although the speciesis distributedin the regionextremely unevenly,its averagedensity levels in theprinciple habitats occupied during the breeding season arerather similar, and range from 1-300(mostly 10-200) birds per km2. Nestingin agricultural fields(e.g. clover, bare fallow) has been proved in severalparts of theregion. Although the survey routesand survey areas did not coverall of thisgeographical area, the first extrapolative estimates haveshown that recentlyat least10,000-20,000 Curlew inhabit the Vologda region in summer. V.T.Butiev, Moscow Pedagogical State University, Biological Laboratory & Departmentof Zoologyand Ecology,Kibalchicha Str., 6, building5, Moscow129278 Russia. E.A.Lebedeva, Russian Bird Conservation Union, Shosse Entusiastov, 60, building1, Moscow,Russia

13yT•,eB,B.T., Ae6e/•eBa, E.A. '1998. 13oa•,mo•i spoumuen Numenius arquata • Boaoro/•c•o•i o6aac?•ua ce•epee•ponellc•coll Pocc•. InternationalWader Studies 10: •299-302.

Introduction In thispaper we analyseour data on the distribution andpopulation density of Curlewin theVologda CurlewNumenius arquata is oneof a groupof region.Although this region occupies a ratherlarge speciesin whichrecently numbers have declined part of north-EuropeanRussia, to date,there have rapidly or evencompletely disappeared from rather not beenany publisheddata on the Curlew largegeographical areas; such a processis most populationsin this area. pronouncedin the southernparts of the Curlews breedingrange. Thesetrends have already been reportedboth in Russianand foreignpublications Study area and methods (e.g.Cramp & Simmons1983). As highlightedat a Vologdaregion is situatedin the north-north-westof workshopon rarebreeding birds in the central EuropeanRussia, mostly within the middle and EuropeanRussia, the speciesis reportedas recently southerntaiga subzones and occupiesan areaof rare,or extremelyrare, with a decliningtrend in five 145, 700 km 2 between 61036' and 58027' N, and 34ø12' out of eightadministrative areas (Moscow and and 47010' E. Forestsare the prevailingvegetation surroundingregions), and hasnot beenrecorded typesin the region,covering c. 60%of its territory breedingat all in threeother regions (Butiev 1990). (80-85% in the northern and 40-60% in southern This threatened status of Curlew in Russia has parts). Ratherlarge areas have been recently resultedin the inclusionof the speciesin the new transformedinto clear-cutsof differentage. In the edition of the Red Data Book of Russia. As a taigazone, natural meadows are restricted mostly to consequence,it is now importantto obtainthe most theflood-plains; however, their size is enlarging up-datedata on the speciesdistribution and density rapidly due to recentintense development of levelsin differentparts of the breedingrange, as agriculture,which hasincluded the drainageof well as to highlightthe areaswhere the Curlews virgin areasfor agriculturalpurposes, and an populationis still more or lessstable. increasein the areaof artificiallysown pastures and Unfortunately,such information for European hay meadows.By the end of the 1970smeadows Russiais extremelyscarce. coveredabout 10% of thisterritory, however their extenthas more than doubled in recentyears.

299 International Wader Studies 10: 299-302

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Figure1. Locationof researchareas and surveyroutes during our studiesin 1970-1993in the Vologdaregion and main geographicalnames mentioned in the text. Agriculturalhabitats with variouscrop types occupiesSphagnum-dominated raised bogs, various occupy,in differentdistricts, from 5% to 25% flood-plainmeadows, tussocky pastures and hay- (Antipov1981). Ratherlarge areas are coveredwith meadows on fluvial terraces, wet clear-cuts, as well bogsand peatlandsof differenttypes. as drainedhay-meadows, various types of fallow lands,and even agricultural fields with spring Our studieswere conductedin the springand cerealsand perennial crops. Curlew were found summer1970-1993 mostly at the western,northern alsoon the floatingmats of lakes(for exampleat the and centralparts of the Vologdaregion. The Katromskoyelake). extremeeastern parts have only been explored ratherpoorly. Data on phenology,spatial The recentdistribution of Curlewswithin the region distributionand breeding ecology of Curlew were is not uniform:in someareas the specieswas obtainedduring intensive studies in the Kharovsk recordedregularly and was rather abundant,while district (1970-1978;150 kiT[2 area;centre of the in otherparts with almostsimilar habitat types, it region),Verkhovazhye district (1979-1986; 120 km2; wasabsent or only foundsporadically (Figure 2). north of the region),at temporarystations on the Curlewswere not recordedat all in the open shoresof Sheksninskoyewater reservoir(1983, habitatsalong the westerncoasts of the Kubenskoye 1986-1987,1990-1993; 50 km2;centre of the region), lake,only singlebirds were observedin the as well as during the rapid surveyswith the useof a meadowsand marshyareas of the middle reaches vehicle in 1986-1987 and 1992-1993 in various of the Uftiuga river (flowinginto the Kubenskoye coastal areas of central, northern and western lake), at the easternshores of Beloyelake, alongthe Vologdaregion (total length of routesc.1,200 km, middle reachesof the Sukhonariver, and alongthe 36 surveyedareas). Counts were made on both banks of the Suda river. In those areas where repeatedand unrepeatedroutes (total length c. 2,000 Curlewsbreed regularly, their distributionis also km) with further calculationsaccording to Naumov rather restricted,and is determinedby the location (1963),as well as on the sevenintensive plots from and availabilityof suitablebreeding sites, as well as 5-20ha each(with regularsurveys every year by the intensityof humaninfluence on theseareas. lasting3-10 days). Thebirds were almostabsent in the vicinityof large The locationof the main researchareas and survey human settlements. routes as well as the main localities mentioned in the textare shownin Figure1. In favourable localities Curlews even formed small colonies,although the distancebetween the nests Results wasrather large. For example,at theKatromskoye lake (12 km2) from four to sixpairs were breeding in Distribution and habitat preferences differentyears on the 5-6 titl Eof the floatingmats. We foundthat althoughthe humaninfluences on There,Curlews preferred only the partswith large naturalhabitats are significantlyincreasing in the openareas with Sphagnum,sparse sedge-grasses taigazone of north-EuropeanRussia,and Carexspp., Andromeda polyfolia, Cassandra calyculata. particularlyin Vologdaregion, Curlew are still a A similar, uneven distribution was observed on the widespreadwader and areeven considered vastdrained, natural meadows along the $yt river commonlocally. During thebreeding season it (Kharovsk station). Densities of Curlew in various

300 Butiev& Lebedeva:Curlew Numeniusarquata in the Vologdaregion of north-EuropeanRussia

Speciesnotrecorded ß Average densities<10 ind./km • O Averagedensitiesfrom 40-60 ind./km • O Averagedensitiesfrom 10-40ind./km e O Average densities>60ind./km •

Figure2. Distributionand densitylevels of Curlew in Vologdaregion according to the studiesin 1970-1993. habitattypes during the breedingseason (May- agriculturalfields as well. In Kharovskdistrict one June) are shown in Table 1. nest was found in a field of bare fallow, whilst two nestsin Verkhovazhyedistrict were placedin clover Table 1 shows that densities are rather similar in fieldsat the edgeof a flax meadow. differenthabitat types (even taking into accountthe Breedingterritories were identifiedon the basisof unevendistribution of the speciesin the studyarea). the alarm behaviourCurlews give towardsthe Noticeablysmaller densities are foundin the wet observer,potential predators or birdsfrom clear-cuts,as the specieshas started to settlein these neighbouringpairs, most were 140-200m in habitatsonly in recentyears. Although some birds diameter(n=30). At the sametime, one of the pairs countedduring the surveys,especially in breedingat the floatingmat of the Katromskoye agriculturalareas, were evidently non-breeding but lake defendedan areaonly c. 100m in diameter. only foraging,it seemsquite probable from the While nestingin the meadows,birds feed within, or similarityin densitiesthat Curlew are alreadymore in closevicinity of, the nearestbreeding territory; or lessadapted to a variety of natural and semi- while nestingon peat-bogsor on floatingmats they natural areas. flew up to 1 km to forageon meadowsor agriculturalfields. Similarly,large densities of Curlew are knownonly Table1. Averagedensities of Curlewduring the breeding in the neighbouringKostroma region, where the season(May-June, 1970-1993) in varioushabitat types of speciesdensity in lowlandparts was 60 individuals Vologdaregion. per km2 (Balandin& Kuznetsov1990).

Some data on breeding ecologyof Curlew in Vologda region Low-grasspastoral meadows 2 - 200 Curlew arriveon breedinggrounds in the centreof Natural hay-meadowswith Vologdaregion from the middle of April, but in the drainingcanals 8 - 100 coldsprings (such as 1976and 1985)they only Patchyhay-meadows surrounded by arrivefrom earlyMay. Migratingbirds can be seen shrubs or woodlands 40 - 60 displayingduring shortstopovers as well: at the Wet grasslandsused for Kharovskstudy area, small flocks (up to 10 birds) hay-harvestingwith high vegetation 10-100 were observedin 1975after 29 April, part of these Flood-plaintussocky pastoral birdswere performing song-flights, and on 4 May grasslands 20 - 250 five maleswere displaying.However, later in the Fieldswith perennialcrops breedingseason only two pairswere left. Evidently, (clover, alfalfa etc.) 10 localbirds settle on breedingterritories immediately Fieldswith springcereals in the after arrival, as the first territorialpairs were flood-plains 10 - 300 recordedin the period3-15 May. Fields with winter cereals 20 Raisedbogs (surveyed only locally) 20 NestingCurlews are found not onlyin naturalhay- Wet clear-cutsof 1-3 year age 1 meadowsor pastoralgrasslands, but alsoin Sphagnumfloating mats on lakes 10 - 20

301 Internattonal Wader Studtes 10. 299-302

The period from settlementon the breedingterritory estimatedthe localpopulation of this species to the startof nest-constructionand egg-layingis breedingon the raisedbogs of the Ilmen' lake basin very short. The first nestwith a completedand even at 1,400-1,800pairs. slightlyincubated clutch was found on 17 May (1977)and on 13 May (1993). On 6 June(1976) we Nevertheless,we tried to extrapolatethe total recordedthe startof hatchingin one of the nestsand numberof Curlewsinhabiting this area, based on on 3 June(1974) downy chicks were foundin the averagedensity estimates in differenthabitat types, vicinity of the nest. Takinginto accountthat and on the area coveredby eachhabitat within the incubationlasts in thisspecies for c.29 days region. Thesecalculations have revealed,that the (Kozlova1962), calculated dates for the startof egg- numberof Curlewsduring the breeding period in layingfell between1-10 May in the two lattercases. Vologdaregion is between10,000-20,000 individuals (includingnon-breeding birds). Accordingto our Nestsare placed in smalldepressions (in the brief observationsin the Arkhangelskregion and meadowsor low-grasspastures), or in hollows Komi republic,Curlews are alsocommon in more within the Sphagnumor sedgehummocks (on the northerntaiga parts. floatingmats). In the latter casessuch hollows in the hummocksare made by thebirds themselves. The taigazone of north-EuropeanRussia supports Three nests, found on fallow lands and clover fields, the largestknown populationsof the speciesin the were lined with dry stemsand leavesof grasses. wholeof easternEurope; therefore, protection of the speciesin theseareas is nowadaysextremely Eggsizes were as follows(n=12): length important. 68.6+0.7mm (range63.9-70.8 mm) and breadth 46.3+0.8mm (range41.1-48.5 mm). References Antipov,N.P. 1981. Lakelandscapes in the Vologdaregion. Hatchingwas observedafter 1-10June. Downy In: A.A. Lyapkina(ed.) Lake resources ofthe Vologda chicksremain in the vicinityof the nestfor some region,pp. 5-14. Vologda.In Russian. time, and movefurther within the breedingterritory Balandin, V.O. & Kuznetsov, A.V. 1990. Curlew in the in the periodup to fledging. agriculturallandscape of Kostromalowland. In: Rarebirds of the Nechernozemny Centre: proceedings of Post-breedingmovements start from the firsthalf of theConf. "Recent state of rare breeding bird populations Julyand continueuntil the end of July. Evidently at theNechernozemny Centre of theUSSR" youngbirds leave by the firsthalf of August;no pp. 160-161. Moscow. In Russian. localCurlew were recordedafter 15 August. In the Butiev,V.T.(ed.) 1990. Distributionof rarebreeding (or moresouthern Tver regionthe last singleCurlews formerlybreeding) bird speciesin the seenwere recordedon 21 September(Nikolaev administrativeregions of EuropeanRussia. In: Rare 1985). Similarearly autumnmigration is known for birdsof the Nechernozemny Centre: Proceedings ofthe othernorth-European countries (Cramp & Simmons Conf."Recent state of rare breeding bird population at 1983). theNechernozemny Centre of the USSR ". As well asbreeding birds, non-breeders in flocksof Appendix2, pp. 178-182.Moscow. In Russian. five or six,very occasionallyup to 20 birds,were Cramp,S. & Simmons,K.E.L. (eds.). 1983. Numenius alsorecorded in the regionthroughout the whole arquataCurlew. In: TheBirds of theWestern summer,foraging in the variousmeadows and Palearctic, Vol. III. Waders to Gulls. agriculturalfields. For example,12 non-breeding Oxford Univ. Press. Curlews were recorded on one of the meadows of Kozlova, E.V. 1962. Aves. Charadriiformes. Suborder Kharovskdistrict in late May 1976and 21 Curlew Limicolae.In: A.I. Ivanov (ed.),Fauna of the USSR. were observedon the easternshores of the Beloye Vol. II, Issue 1, Part 3. USSR Acad. of Sci.Press, Lake between 20-30 June 1985. Leningrad. In Russian. Mischenko, A.L. & Sukhanova, O.V. 1998. Waders of the Discussion Novgorodregion: peculiarities of their distribution The uneven distribution of Curlew within the and importantbreeding areas. International Wader Studies 10: this volume. Vologdaregion, the almostcomplete absence of any otherquantitative data on its numbersor densities Nikolaev,V.I. 1981. Someecologo-geographical in thisarea, and especiallythe lackof data on peculiaritiesin avifaunaof raisedbogs at the upper Curlew aggregationsin the ratherlarge boggy areas Volgaarea. In: A.A. Inozemtsev(ed.), Animal world in the central,eastern and south-easternparts of the ofthe forest zone of EuropeanRussia, its protection and regioncaused many difficulties when we tried to use,pp. 130-134.Kalinin State Univ., Kalinin. In Russian. extrapolatethe total numberof the Curlew Nikolaev, V.I. 1985. On the distribution of some bird populationfor the whole studyarea. The latter constraintwas the mostimportant, as data is speciesin Kalinin region. In: V.I. Zinoviev (ed.), availablefor neighbouringTver (formerlyKalinin) Influenceof anthropogenic factors on the structure and and Novgorodregions, where it is known that functioningofbiocoenoses, pp. 140-145.Kalinin State Curlew arefound in largenumbers on the large Univ., Kalinin. In Russian. peatlands(Nikolaev 1981, 1985; Mischenko & Sukhanova1998). Mischenko& Sukhanova(1998)

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