Pacific Golden Plovers <I>Pluvialis Fulva</I> and Other Waders on The
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Pacific Golden Plovers Pluvialis fulva and other waders on the Samoan Islands: Wintering in a changing Polynesian landscape ULF BEICHLE LandesmuseumNatur und Mensch Oldenburg,Damm 38-44, D 26135 Oldenburg,Germany, e-maih ulf. beichle @ web. de Beichle, Ulf, 2001. Pacific Golden Plovers Pluvialisfulva and other waders on the SamoanIslands: Winter- ing in a changingPolynesian landscape. Wader StudyGroup Bull. 96: 40-46. Countsand observationsof waderswintering on the SamoanIslands, Oceania, in Februaryand March 1999 andMarch andApril 2000 arereported. The mostabundant waders were Pacific Golden Plovers Pluvialisfulva. This speciesbenefits from the rapidly changinglandscape, as primary rain forestis turnedinto cultivatedland. 2000 individualsof P. fulva are makinguse of thesetropical islands as their non-breedingarea. The major- ity, 800-1000, is concentratedon the islandof Upolu, especiallywithin the urbanenvirons of Apia. Pacific GoldenPlovers have showna considerablechange in behaviourduring the last few yearsby makinguse of smallgarden lawns. Other species wintering in or migratingthrough the Samoanislands are Wandering Tattler Heteroscelusincanus, Ruddy Tumstone Arenaria interpres,and Pectoral Sandpiper Calidris melanotos. During earlieryears (1975-1998), Bristle-thighedCurlew Numenius tahitiensis and Lesser Yellowlegs Tringafiavipes were also recorded. INTRODUCTION fore data were collectedin a wide rangeof locationscover- ing all major habitatsand for every time of the year. The Polynesianislands are known as non-breeding areas for From 2 to 21 March 1999 and from 22 March to 9 April arctic waders(Mayr 1945, Watling 1982, Pratt et al. 1987). 2000, the numbersof migratoryshorebirds were counted on Despiteits remotelocation (e.g. about9,000 km from wader the islandsof Upolu, Savai'i and Nu'utele (Figure 2). This breeding groundsin west Alaska and northeastSiberia), time of year was chosenbecause the adults have not yet severalspecies migrate annually to thisregion (Williams & startedto return to their breedinggrounds. Moreover it is Williams 1988, Johnson & Connors 1996, Johnson et al. generallytoo early for the arrival of new individualsfrom 2001). This is why this type of migratorybird was calleda further south(although spring migration of waderswinter- "globe-spanner"(Chapman 1924). ing in the SouthernHemisphere does start in aboutthe mid- This studyis the first to report on numbers,distribution dle of March (Byrkjedal & Thompson1998)). and habitats of waders in the SamoanIslands, part of the Countswere carriedout alongall the coastlinesby car or Polynesianarchipelago (Figure 1). Previously,population on foot. In the hinterland,potentially suitablehabitat was estimateshave been made only for the comparativelysmall checked on foot wherever access was difficult. eastern islands of American Samoa (Amerson et al. 1982). For Pacific GoldenPlover, maps were prepared showing The Samoanislands are of volcanicorigin with mountains the distributionof flocks accordingto the following size- reachingto 1,858 m. A few decadesago, primary forest cov- classes:5-10, 11-50 and >50 individuals. ered the islandsand was virtually untouched.Villages and The size of territories used by Pacific Golden Plovers plantationswere confinedmainly to the coastalareas. Today, wasdetermined by observingindividual birds regularly for vast areasof native foresthave disappearedand rain forest 5-9 daysand by measuringthe areasused and defended by birdshave sufferedsevere loss of habitat.Several migratory each. species,however, have benefited by makinguse of the areas that have been cleared and turned into cultivated land. The RESULTS purposeof this study is to documentthe presentstatus of migratoryshorebirds in Samoaas well astheir habitatselec- Pacific Golden Plover Pluvialis fulva tion. This baseline information will mean that future trends that may resultfrom the rapidly changinglandscape can be Numbers accuratelyassessed. The majority of Pacific Golden Plovers - 1,000-1,200 - MATERIAL AND METHODS were found on the westernislands of Savai'i, Upolu, Apo- lima, Manono andthe Aleipata islandsoff Upolu (Nu'utele, When the author'sstudies on Samoanbirds began in 1975, Nu'ulua, Fanuatapu,Namu'a). About 800 of thesewere on migratorywaders were observedonly sporadically.Species Upolu and200-300 on Savai'i. On Upolu, only a few places and habitatsused were recordedqualitatively. The author were suitablefor largenumbers. The majoritywere in small spentmore than four years in Samoa,three years continu- groupsand individuals scattered widely overthe island.The ously.Other visitswere madein a varietyof seasons.There- relatively small islandsoff Upolu and Savai'i were suitable Buffetin 96 December 2001 40 Beichle: Waders in Samoa 41 ß.•: •''"'** ' • %, • I HAWAIIANß IS ß: .-' • -, WAKE ß Honolulu ß ":, ;.;• .rlp.•u•.•s .. - • • / /' -•'• '• • •"'. "' ' I / •" ':.% /••• . -.•"-• '.".. • I.F,•/ •-"•" . .... -,..'-,, / .:- -EASTER IS. Figure 1. Waders visitingthe Samoan Archipelagohave to cover a distanceof more than 9000 km from their breedingareas, mainly fly- ing over the Pacific Ocean. (Map, slightlymodified, after Amerson et al. (1982). Distancesare in kilometres.) for only a few individuals.It seemslikely thatthese birds fly In the vicinityof Apia, PacificGolden Plovers concentrate to the larger islandsto feed or roost. on Mulinu'u Peninsula (Plate 3), on the golf course at The populationof the easternislands of the chain(Ameri- Fagali'i village and on Fagali'i airstrip. Other important can Samoa)is 500-600, comprising200-300 on Tutuila and places are a reclaimed area in the City of Apia, various an estimated200-300 on the Manu'a-Group (author's un- sportsfieldsincluding those at Matafagatele,University of publishedobservations). Therefore the totalpopulation of all Samoaand Apia Park, the L.D.S. compoundin Lepea and the islandsof the Samoangroup is about2,000 individuals. several lawns at Alafua and Moamoa. A relatively new site for wadersis the Catholic church Distribution centrerecently set up in Tuana'i-Leauva'a. This quiet com- poundseems ideal for Pacific Golden Plovers,as it borders PacificGolden Plovers were concentratedin the westernpart on a mangroveswamp with muddy substrate. of the Samoanisland chain with the majority concentrated Important wintering and summeringgrounds on Upolu on the northcoast of Upolu (Figure3). Numberswere great- (seeFigure 3) are:Faleolo International Airport (1), Catholic estthroughout the year in the vicinity of the City of Apia and churchcentre Tuana'i-Leauva'a (2), the city of Apia andits on the Internationalairport at Faleolo.The lawnsof Samatau vicinity (3), Fagali'i golf courseand airstrip (4), Lufilufi churchand schoolat the westernmostend of Upolu are also church lawn (5), Solaua cattle farm (6), Faleffi inland cattle attractiveto a smallergroup of this species. farmswest of Mafa Pass(7), Richardsontrack, roadsides and Api a ß Olosega Upolu **/ Tutuila Ofu,,. Samoa / "•Pa•oPago Ta'u t 50 km t American Samoa Figure 2. Within the Samoan islandchain, the main land masses are the larger islandsin the west of Savai'i and Upolu. Waders are found mainly on Upolu, where cultivationof land is most advanced. Bulletin 96 December2001 42 Wader Study Group Bulletin 20...k..m, Figure 3. Concentrationsof PacificGolden Ploverson Upoluin 1999 and 2000. Small squaresindicate 5-10 birds, mediumsquares 11- 50 and large squares>50. Numbersidentify each site as follows:Faleolo InternationalAirport (1), Catholicchurch centre, Tuana'i-Leauva'a (2), the City of Apia and its vicinity(3), Fagali'igolf courseand airstrip(4), Lufilufichurch lawn (5), Solaua cattle farm (6), Falefgtinland cattlefarms west of Mafa Pass(7), RichardsonTrack, roadsidesand cattle farms (8), Aleipatabeach and Aleipataislands (9), Cape Tuiolem0 beach (10), Lotofagaarea (11), Siumu inlandlawns (12), Safata Bay beach (13), Samatau churchand schoollawn (14). cattle farms (8), Aleipata beach and Aleipata islands(9), considerably.During high tide, when the coralswere cov- CapeTuiolemfi beach (10), Lotofagaarea (11), Siumuinland eredby water,both birds defended their territories vigorously lawns (12), Safata Bay beach (13), Samatauchurch and (Plate 7). school lawn (14). Ruddy Turnstone Arenaria interpres Size of territories Duringthe two censusperiods, Ruddy Turnstones were only Thetwo largest territories - 1,925m 2 and1,200 m 2- were found once.This was on 4 April 2000 when 16 were seen both held by adult males (Plate 1). The smallestterritory feedingon a lawn westof the old marketbuilding in Apia. coveredonly 184 m 2. The average size of territories(n = 22) When disturbed,they would fly to rest on a nearby stone was876 m 2. Adult males were more aggressive than females wall. In view of the date,these may have beenmigrants. In or immatures. previousyears, 5-10 Turnstoneswere sometimesobserved on the reclaimedarea in Apia and on freshly cut lawns in Feeding behaviour front of the parliamentbuilding on Mulinu'u Peninsula. In Samoa, Turnstonesalways seem to be nervous and Food of Pacific Golden Plovers in Samoa consists of inver- easilydisturbed. Nevertheless they do not avoidthe presence tebrates.Berries and other small fruit on the groundare not of humans.They are usuallyfound in and aroundthe city of available.Therefore foraging behaviour is adaptedto small Apia. fast-movingprey items. Birds walk slowly,taking only a few steps,then wait motionlessbefore rushing towards their prey, Pectoral Sandpiper Calidris melanotos peckingit with a fastmovement of the neck (Plate2). Simi-