Waders Breeding on Wet Grasslands in the Countries of the European Community &Hyphen; a Brief Summary of Current Knowledge O

Waders Breeding on Wet Grasslands in the Countries of the European Community &Hyphen; a Brief Summary of Current Knowledge O

50 H6tker: Grassland Waders in the EC Waders Breeding on Wet Grasslands in the Countries of the European Community - a Brief Summary of Current Knowledge on Population Sizes and Population Trends Hermann HStker HOtker,H. 1991. WadersBreeding on Wet Grasslandsin the Countriesof the EuropeanCommunity - a Brief Summaryof CurrentKnowledge on PopulationSizes and PopulationTrends. Wader StudyGroup Bulletin61, Supplement:50-55. Recentestimates of the populationsizes of grasslandwaders (Oystercatchers, Lapwings, Dunlins, Ruffs, Snipes, Curlews, Black-tailed Godwits and Redshanks)breeding in the countriesof the European Community(EC) are given (Table 1). Probablymore than half of all wadersof the EC breed on wet grasslands.In the EC all grasslandwaders except Oystercatchers are declining.The main reasonfor the declineis habitatloss due to agriculture.Efforts to protectthe grasslandwaders are briefly reviewedand somegaps in theknowledge on grasslandwaders are mentioned. Hermann H6tker, Institutfar Haustierkunde,Universitfit Kiel, c/o WWF Wattenmeerstelle,Norderstr. 3, 2250 Husum,Germany. Introduction compilation were taken from the contributions of chapter 2 of this issue As outlined earlier in this issue, political (Beintema 1991a; Davidson 1991; Devos, decisionswhich have a potential influence on Kuijken & Meire 1991; Dubois, Mah6o & wet grasslandhabitats are increasinglyoften HOtker 1991; Frikke 1991; Klinner 1991; taken on the level of the European Reinke 1991; Ruffno & Neves 1991;Smith Community (EC). This holds especiallytrue 1991). for agriculturalpolitics. Therefore it seemsto be useful to compile the available information on waders breeding on wet Population estimates grasslands for the countries of the EC, although this region is not directly a single The most recent published information is 'biogeographic'unit. compiled in Table 1. Data from Greece, where Oystercatchers Haematopus The aims of this paperare: ostralegus,Lapwings VaneIIus vaneIIus and Redshanks Tringa totanus are known to 1. to give recent estimates of population breed, are lacking. The Greek populationsof sizes of waders breeding on wet these speciesare, however,probably so low grasslandsin the countriesof the EC; that they do not influence greatly the estimates for the EC as a whole. The same 2. to review the populationtrends of these holds true for several Spanish provinces waders; where no information was available. 3. to list the threatsfor the grasslandwader Data from the former German Democratic populationsand their habitats; and Republic are not includedbecause the GDR did not belong to the EC at the date of the 4. to identify gapsin the knowledgeof the workshop which is the basis of these wet grasslandwader populationsin the proceedings. EC. Most of the estimatesgiven in Table 1 are Unless otherwise mentioned, the data for this fairly recent. Table 1 and also Table 2 WSG Bulletin61, Suppl.: 50-55 (April 1991) H6tker: Grassland Waders In the EC 51 :'9. •;• • , , , • , WSG Bulletin 61, Suppl.: 50-55 (April 1991) 52 H6tker: Grassland Waders In the EC roughly reflect the situation of grassland on grasslandsin the EC are very rough waders in the second half of the 1980s. estimates:Oystercatcher 5%; Lapwing 70%; Dunlin (only the Danish population, 700 Table 1 and 2 include all wader species pairs); Ruff 100%; Snipe 70%; Black-tailed which are considered as 'meadow birds' in at Godwit 95%; Curlew 30%; Redshank 20%. least a part of their breedingrange in Europe, Accordingto these figures rather more than although some of them usually nest also in 600,000 pairs of waders breed on wet other habitats. For example most grasslandswithin the EC. These are about Oystercatchersoccur in coastalhabitats, most 10% of the total European(excluding USSR) breeding Redshanks are found in salt wader populationand more than 50 % of the marshes, and only the Danish Dunlin total wader population of 1,050,000 - Calidris alpina schinzii population can be 1,220,000 pairs in the EC (calculatedfrom considered as grassland-breeding.British Piersma1986). Wet grasslandscan therefore Dunlins occur in upland habitats (Sharrock be considered to be the most important 1976) and the rest of the continental breedinghabitat for wadersin the EC. European birds are in saltmarshes.Many Curlews Nurnenius arquata nest on heaths Table 1 shows once more the outstanding and moorlands,but grasslandsare alreadythe position of The Netherlandsas a breeding most important breeding habitats in some area for grassland waders, especially for countries. Black-tailedGodwits and Oystercatchers. The non-grassland-breedingparts of these meadow bird populationsmust be considered Population trends here becausethe grassland-breedingparts of the populationsare not isolatedfrom them. Table 2 gives a rough summary of the Geneticexchange between the birdsbreeding available information on the population on different habitats may be frequent. In trendsof grassland-breedingwaders in some some cases, when grasslandhabitats are of countries of the EC. The overall EC trends low quality for the waders, a non-grassland were estimatedfrom the trendsof the single breeding site may even be the place where countries. In the case of different trend most or all of the young are producedwhich directions in different countries, the countries later settle on the grassland.Grassland in this with the bigger parts of the populationwere case is the B-land and the other habitat the A- valuedhigher. Unfortunatelynot all the trend land in the sense of Beintema (1991b). In estimatesare basedon countrywideseries of extreme cases, wet grasslands may hold count data. The lack of such data, as well as considerablewader populationsonly because underestimatesof populationsizes in former there are some other good habitats nearby years (see e.g. Beintema 1991a; Devos et al. which produce the chicks that are necessary 1991), result in this rather unsatisfactory to balancethe inadequatereproduction in the situation. Nevertheless, each of the trends wet grasslands.In contrast, wet grasslands shown in Table 2 was carefully estimated may in the case of the Lapwing be the with the help of many experts and by habitatswhich allow arable breeding of this evaluatingmany sets of local countingdata. species(Matter 1982, Galbraith 1988). For Although the speed of the decreasesand Lapwings, Ruffs Philomachus pugnax, increases in population sizes cannot be SnipesGallinago gallinago and Black-tailed measured at present, the directions of the Godwits Limosa limosa wet grasslandsare trendsare very probablycorrect. by far the most importantbreeding habitats within the countries of the EC. Within the EC area the situationis alarming: all species,except the Oystercatcherand the It is hard to estimatehow many wadersin the Curlew, are decreasing in numbers. With EC actually breed on wet grasslands. Dunlin, Ruff, Snipe and Redshank the Different species use this habitat to a decreaseoccurs consistentlyin nearly all different extent in different countries. The countries.Even the most numerousgrassland followingpercentages of populationsnesting wader, the Lapwing, is decliningin breeding WSG Bulletin61, Suppl.:50-55 (Apd11991) H6tker: Grassland Waders In the EC 53 Table 2. Population trends of grasslandwaders in different European countries. +: increase;o: stablepopulation; -: decrease;7: no information. Oyster- Lapwing Dunlin Ruff Snipe Black- Curlew Redshank catcher Vanellus Calidris Philo- Gallinago tailed Numenius Tringa Haematopusvanellus alpina machus gallinago Godwit arquata totanus ostralegus pugnax L. limosa Denmark• + .... + + .9 WestGermany a + ....... The Netherlands• -I- O - - - -I- - Belgium4 -I- 0 - -I- . 0 = GreatBritain s -I- - - 0 - 0/- = = France• 0 - 0 - -I- - O/- Italy7 - -I- -I- EuropeanCommunity -I- sources:l:Frildce 1991, Frildcepers. comm.; 2: Klinner 1991, I-I•terlein pers. comm., OAG Mfinster pers. comm.,R6sner pers. comm. 3: Beintema1991a; 4: Devoset al. 1991; 5: Smith 1991, Smithpers. comm.; 6: Duboisetal. 1991;7: Tinarelli & Baccetti1989, Serrapers. comm. numbersin most partsof its Europeanrange. Netherlands and Belgium the smallest The increaseof the smallItalian populationis proportionof populationsis on the decline. believed to be the result of lower hunting The situationis worst in Germany, where all pressurein recentyears (Tinarelli & Baccetti speciesexcept Oystercatchers are declining. 1989). The total EC breedingpopulation of the Black-tailed Godwit is decreasing, althoughthere are (still?) places where this Reasons for population trends trend is reversed. The situation for the and protection Curlew is not very clear. The main reasonfor the declineof grassland These findings fit well into Beintema's waders in the EC is very obviously habitat (1983) schemeof preferanceand toleranceof destruction.Breeding habitats are most often meadow birds for intensity levels of lost due to changesin agriculturalpractices, agriculturalmanagement (for an illustration particularlydrainage and the intensification of the schemein this volume see Witt 1991). of farming, as reported from Denmark Orderingthe speciesin Table 2 accordingto (Frikke 1991), The Netherlands (Beintema the percentagesof 'declines' gives almost 1991a), Belgium (Devos et al. 1991), exactly the same sequenceof speciesas in Germany(Klinner 1991, Reinke 1991), Great Beintema'sscheme. The only exceptionis the Britain (Davidson 1991, Smith 1991), and Curlew, which declinesrelatively more often France (Dubois et al. 1991). In this respect than expected. The declines of Curlew the transition

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