Report of the Dutch-Mauritanian Project Banc D'arguin 1 9
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Report of the Dutch-Mauritanian project Banc d'Arguin 1985-1986 edited by : Bruno J. Ens Theunis Piersma Wim J. Wolff Leo Zwarts _^^ RIJKSINSTITUUT VOOR NATUURBEHEER %Uy Pare National du Banc d'Arguin (PNBA) Dutch Working Group for International Wader-and Waterfowl Research (WIWO Research Institute for Nature Management (RIN) Netherlands Institute for Sea Research (NIOZ) BIBLIOTHEEK RIJKSINSTITUUT VOOR NATUURBEHEER Texel 1989 POSTBUS920 1 6800H B ARNHEM-NEDERLAND R.I.N.-RAPPORT Vr DEDICATED to thememor y of our respected friend Ely ould Elemine WIWO Rapport 25 RIN-rapport 89/6 The WIWO report series intends to be a regular medium by which occasional reports of ornithological expedition or journeys can be published. In this way regular distribution and availability are guaranteed. Large quality differences are accepted, since the authors remain responsible. The RIN reports are amediu m to report on research projects by RIN collaborators. The RIN reports have a limited distribution, mainly within The Netherlands. This report can be ordered by paying Dfl. 35,-o n either: -postal giro account 2.666.009 or toAB N bank account 57.02.16.613 of Stichting WIWO,Ewijk ,Th e Netherlands, or -postal giro account 51 60 6 48 of Rijksinstituut voor Natuurbeheer,Leersum , The Netherlands. Postage is included in the price. This report is also to be published inFrench . -"v *-»~ v >• -\ COLOPHON V Typing :Michael a Scholl Figures :Wiebere n Planting Bird drawings: Jos Zwarts J CONTENTS 1 INTRODUCTION 7 2 ORGANISATIONAN D ITINERARY 12 3 METEOROLOGICALMEASUREMENT S 16 4 TIDEMEASUREMENT S 43 5 WADERCOUNT S 57 6 VISIBLEMIGRATIO N 68 7 WADERCATCHE S 77 7.1 Methodology 77 7.2 Capture totals 85 7.3 Recoveriesan dresighting s 87 8 WADERBOD YCOMPOSITIO NANALYSI S 93 9 NOTEO NGULL SAN DTERN S 104 10 SYSTEMATICLIS TO FBIRD SAN DMAMMAL SOBSERVE D 111 11 TIMEBUDGE TO FWADER S 196 12 WADERENERGETIC S 199 12.1 Heat stresso nth eroos t 199 12.2 Saltstres scage dbird s 200 12.3 Energeticcos to fweigh tgai n 201 13 FORAGINGOYSTERCATCHER SO NTH EBAN CD'ARGUI N 203 14 FEEDINGBEHAVIOU R OFWHIMBRE LAN DANTI-PREDATO R 205 BEHAVIOURO FIT SMAI NPRE YTH EFIDDLE R CRAB (UCATANGERI ) 15 LISTO FMARIN EPHANEROGAMS ,MOLLUSCS ,POLYCHAETE S 208 ANDCRUSTACE AOBSERVE DALIVE DA TTH EBAN CD'ARGUI NI N 1985AN D 1986 16 DISTRIBUTION,BIOMASS ,RECRUITMEN TAN DPRODUCTIVIT Y 220 OFANADAR ASENILI S- ABSTRAC T 17 FISHESAN DSHRIMP SO NTH ETIDA LFLAT SA TTH E 222 BANCD'ARGUI N 18 RECOMMENDATIONS FORTH EMANAGEMEN TO FTH E 228 PARCNATIONA LD UBAN CD'ARGUI N 19 REFERENCES 229 kPPENDI XI 236 WADERBIOMETRIC S 236 1 Oystercatcher 236 2 Avocet 239 3 RingedPlove r 240 4 KentishPlove r 250 5 GreyPlove r 257 6 Knot 264 7 Sanderling 276 8 LittleStin t 284 9 CurlewSandpipe r 290 10 Dunlin 300 11 Bar-tailed Godwit 315 12 Whimbrel 320 13 Redshank 323 14 Turnstone 327 APPENDIX II 335 Maps 335 INTRODUCTION About 7millio ncoasta lwader s (.Limicoles,Charadrii )migrat eannuall y betweenvas tarcti can d subarcticbreedin garea san d temperatean d tropicalwinte rquarter sscattere d along theeaster n shoreso fth e AtlanticOcean .Afte ra shor tbreedin g seasoni nth earcti c tundraso fN E Canada,Greenland ,Iceland ,Scandinavi a andth enorther n partso fth e USSR thesebird sarriv ea t thetida lflat so fth eWadde nSe aan dth e estuaries ofGrea tBritai ni nlat esummer .Afte rmoultin g theirfeathers , somewader ssta y theret owinte rbu tman yother smigrat efurthe r southt o spend thewinte r inS WEurope ,West-Africa ,an deve nsouther nAfrica .A t leasthal fo f thecoasta lwader susin g theEas tAtlanti cflywa y spendth e winteri nthes eAfrica nwinte r quarters (Piersmae tal . 1987). About 1980i tbecam eclea rtha t thetida lflat so fth eBan cd'Argui n (Fig. 1)i nMauritani awer eon eo fth emos t importantwinterin garea s along theEas tAtlanti c flyway.Ove r 2millio nwader swer ecounte di n that regioni nwinte r (Trotignon 1980,Altenbur g etal . 1982).Remarkabl y enoughfoo dcondition so nth eBan cd'Argui nappeare d tob emargina l (Altenburge tal .1982) .Roug hcalculation sbase d ondat acollecte d in February 1980showe d that thetota lamoun to ffoo dpresen twoul db e consumedwithi ntw omonth si fn oregrowt ho rresettlemen t offoo d organismswoul d occur.Althoug hsom eregrowt h islikel yt ooccur ,i t remains tob esee nho wthes ebird sar eabl et opu to nsufficien t fati n earlysprin g for theirnorthwar dmigration . Thisquestio n- ho wbird sar eabl et ostar t theirsprin gmigratio n fromth eBan cd'Argui n ingoo dconditio n- forme d thecentra l themeo f theDutch-Mauritania nprojec t "Bancd'Argui n1985-86" . Toanswe rthi squestio nw ehav et okno who wmuc hfoo di savailabl ei n springan despeciall y howmuc hextr a food isproduce d inthi speriod . Secondlyw enee d tokno who wmuc hfoo d isrequire d byth ebird san dwha t isthei rextr anee d topu to nsufficien t fatfo r thesprin gmigration . Finallyw ehav et okno wwhe nth ebird spu to nthi sfat ,whe n theyleav e andwhic h stagingarea s theyma yo rhav et ouse . Thisi sver y shortly theprogramm e of theprojec t "Banc d'Arguin 1985-86"develope d byth eWorkin gGrou pfo rInternationa lWader -an d WaterfowlResearc h (WIWO),th eResearc h Institutefo rNatur eManagemen t (RIN)an d theNetherland s Institute forSe aResearc h (NIOZ).Du et o shortage of funds itwa sno tpossibl e tocarr you t theentir e programme 0 10 20 30 40k m Figure 1.1.Locatio n in Africa and general map of the Banc d'Arguin, Mauritania. in 1985,a s conceived originally. Because the international Wader Study Group had planned an international project to study themovement s of waders during spring migration by means of birds with colour marks in the spring of 1985,i t was decided to carry out only that part of the project "Banc d'Arguin 1985-86"whic h supported the international project and to postpone the remainder of the programme to 1986. From the start of the project it was envisaged thatMauritania n counterparts would take part in the project.Consultatio n with the Mauritanian authorities resulted in a joint Dutch-Mauritanian project in which on theMauritania n side the Pare National du Banc d'Arguin and the Directorate for Nature Protection of theMinistr y of Rural Development took part. The aims of the project "Banc d'Arguin 1985-86"wer e inmor e detail: 1. Studies on spring migration of waders in relation to feeding condition. This part of the programme had to lead toa detailed analysis of the origin ofwader s at the Banc d'Arguin and the timing, patterning and extent of wader migrations from and through Banc d'Arguin in spring,an d toa n apraisal of the physical changes in the birds themselves which allow them these movements. Information on the fate of the birds after they have left the Banc d'Arguin, had to be gained as a result of these local studies. The research programme to reach these aims consisted of three parts,viz .descriptio n of arrival and departure ofwaders ; description of the changes in physical condition of the birds before departure; and description of the routes taken by the waders to reach the breeding grounds and the location of these breeding areas. 2. Studies on the biomass and productivity of the benthic fauna of the tidal flats. This involved in the first place a general survey of the benthic fauna of the Banc d'Arguin in order to obtain a reference value for the biomass of the entire area. Secondly, growth and production rates of selected invertebrates had to bemeasure d in order to obtain an estimate of benthic productivity. This had to be compared with measurements on biomassremova lb ypredator san d othercauses ,carrie d outb ymean so f exclosures.Thirdly ,i tha d tob einvestigate d whetherinvertebrate san d smallfis hmigrat ewit h thetide sbetwee n tidalchannel san d flats,thu s forminga nadditiona l sourceo ffoo d forwader swhic hescap e theusua l methodso flo wtid esampling . 3.Studie s onth efeedin gbehaviou ran decolog yo fwaders . Inth efirs tplac ei tha d tob edetermine d fora sman yspecie so fwader s aspossibl ewha t typean d sizeo fpre y isobtained .Secondly ,fo ron eo r a fewspecie s thefoo dconsumptio n inth efiel dha d tob equantifie di n ordert oestimat e theenergeti c requirement ofth especie s (dailyenerg y intake).Thi swa scombine d withdat ao nlow-tid efeedin gdensitie so f waders inorde r toarriv ea ta nestimat e forth econsumptio na tth e entire Bancd'Arguin .Thirdly ,th eextr afoo d intakeneede d toaccumulat e migratory fat,ha d tob edetermine d forbird s incaptivity .Fourthly ,i t had tob einvestigate d inwil d birdswhethe rfa taccumulatio n priort o migrationi sdu et oa nincreas ei nforagin g efforto ra nincreas ei n availablefood . ACKNOWLEDGEMENTS Theprojec twa ssupporte d financiallyby : - theCommissio n ofth eEuropea nCommunitie s (Brussels); theNationa lGeographi c Society (Washington); theNetherland sMinistr y ofAgricultur ean dFisherie s (TheHague) ; - theShel lInternational eResearc hMi j(Th eHague) ; - thePrin sBernhar d Fund (Amsterdam); theSociet yfo rth eProtectio n ofNatur eMonument s inth eNetherland s ("Natuurmonumenten")('s-Graveland) ; - theNetherlands 'Stat eForestr y Service ("Staatsbosbeheer")(Utrecht) ; theFun d forResearc hfo rNatur eProtectio n (FONA)(Arnhem) ; theBritis hOrnithologica lUnio n (London); - theBachien eFoundatio n (Leiden). Thehel po f theNetherlands 'Societ yfo rth eProtectio no fth eWadde n Sea (Harlingen)i nprefinancin g theprojec twa sinvaluable . 10 Thesuppor t ofth eMauritania nauthoritie s isgratefull yacknowledged .