Pacific Golden fulva and other 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. 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 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 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

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-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- larly smallcrabs of about 1 cm carapacesize are caughton Two PectoralSandpipers were observed behind the Govern- the sandyor muddymangrove areas and beaches. ment buildingon the reclaimedarea in the City of Apia on 6 and 7 April 2000 (Plate 8). This is the first time that this Wandering Tattler Heteroscelus incanus specieshas been reportedfrom the Samoanisland group (Pratt et al. 1987). In view of the date,these birds were pre- Wandering Tattlers are much less commonin Samoathan sumablypassage migrants. They were very inconspicuous Pacific Golden Plovers.Counts along the coastlinevaried andthe colourof theirplumage resembled very muchthat of from 200 to 300 individualsfor Upolu, Savai'i andNu'utele the juvenile Pacific Golden Plovers foraging or roosting together. nearby.Their small size, however,attracted attention. This speciesprefers rocky shores,formed either through On bothdays, the two birdsremained almost all the time volcanicactivity or by corals.Also, especiallyduring low within the samearea, 50 m across.In this particularpart of water, they will often forageon coral reefs.They searchfor the reclaimedarea, water was lying in a wheel-track.Else- invertebrateshidden in rock crevicesor in tidal pools.On the where,water usually seeps away quickly into theporous lava reclaimedarea in Apia, Tattlersfrequently forage on man- rock. The two PectoralSandpipers looked for food by prob- madestructures, such as stonewalls or concretewalls by the ing in the muddy substratewith their long bills, unlike sea.On 4 April 2000, for the first time since1975, oneindi- Golden Plovers, Wandering Tattlers and Turnstonesthat vidualwas observed in Apia' s fishingharbour next to theold peck prey from the surface. market building. On Nu'utele,the sizeof two WanderingTattler territories Bristle-thighed Curlew Numenius tahitiensis was measured. Each used 350 m of the 700 m coral beach. Depending on tide, the area of coral reef varied The Bristle-thighedCurlew is a rare visitor to the Samoan

Bulletin 96 December 2001 Beichle: Waders in Samoa 43

Plate 1. A male Pacific Golden Plover on a lawn in front of the Government Building.This bird defended the largest territory within this study (City of Apia, Upolu, 6 May 2000).

Plate 2. Typical hunting behaviour of Pacific Golden Plover on the Samoan islands: invertebrates are snatched from the short-cut grass of lawns.

Plate 3. Mulinu'u Peninsula in Apia offers suitable habitat for wintering and summeringwaders. PacificGolden Plovers prefer lawns like the one in frontof the ParliamentBuilding (above left) or the Observatory (far right). Wandering Tattlers can be found on the beach of Vaiusu Bay (above right). Both species use the mangrove belt (top).

Bulletin 96 December 2001 44 Wader Study Group Bulletin

Plate 4. Pacific Golden Plover in front of a traditional Samoan house. No waders make use of shady places in Samoa They often keep their bills open to cool down body temperature.

Plate 5. Hand-held lawn-mowers re- place the bush-knives. Golden Plovers benefit from this new technique, as lawns are kept shorter.

Plate 6. Freshly mown lawns are pre- ferred by Pacific Golden Plovers, as they dry up quickly and invertebrates are easier to detect. This male Golden Plover is not disturbedby the dog run- ning by.

Bulletin 96 December2001 Beichle: Waders in Samoa 45

Plate 7. Wandering Tattler roostingon coral debris in its heavily defended ter- ritory on Nu'utele Island, 27 March 2000.

Plate 8. This Pectoral Sandpiper, on the reclaimed area in the city of Apia, is one of the two that were seen on 6 and 7 April 2000. This is the first time that the species has been recorded on the Samoan Islands.

islands.It was not found at all duringthe studiesof 1999 and thighed Curlew and Lesser Yellowlegs suffer from an in- 2000. The last observation was in 1996 when one was seen creasingpressure of humanpopulation along the coastline, on the northeastcoast of Upolu. From 1975 to 1995, only especially on the beaches(Amerson et al. 1982). Bristle- singlebirds were noted. thighedCurlews, in particular,are very sensitiveto human The main areaswhere this specieshas been recordedare disturbance.Moreover many of the sitesthey usedin the past the mangrove and mud flats at Mulinu'u and the sandy have been lost as a result of the destructionof mangrove beachesof Luffluff and Solosolo,all on Upolu. areas,dredging of sand and the pollution of Mulinu'u Bay through the dumping of garbage from the City of Apia. Lesser Yellowlegs Tringa flavipes Pacific Golden Plovers, on the other hand, have benefited from the changinglandscape. Suitable areas are generatedon Since 1975, the authorhas only recordedthis speciesonce a large scale, such as lawns, sportsfields and cattle farms. in Samoa. In September1997, a singleLesser Yellowlegs New techniqueslike motor-drivenhand-lawnmowers permit was observednear the village of Sa'anapuon the southcoast easycutting of grassinstead of the back-breakinguse of the of Upolu. It was searchingfor food during low tide in the bush-knife. Therefore lawns are mown more often than be- mud betweenthe roots of old mangrovetrees. fore offering easy accessto invertebrate food without the birds having to walk through long, wet grass(Plates 4, 5 DISCUSSION and 6). The censusresults suggest that the totalnumber of Pacific Conditionsfor waderswintering or summeringin Samoavary GoldenPlovers wintering in the whole Samoanisland chain considerablyfrom speciesto species.Birds like Bristle- during 1999 and 2000 was about 2,000 individuals. This

Bulletin 96 December 2001 46 Wader Study Group Bulletin figure differs from a studycarried out in 1975 and 1976 in from peopledriving to theupper-floor parking area at theAla theeastern part (American Samoa) by Amersonet al. (1982). Moana Shoppingcentre in Honolulu. At that time, the populationof AmericanSamoa alone was On the Samoan islands, this transformation is more recent estimated at 4,500. There are no data to show whether and Pacific Golden Plovershave only just startedto move numbers have decreased since then. However, it would seem into thisnewly created landscape. It is possiblethat, as a re- possiblethat Amerson et al. over-estimatedthe populationin sult, their numberswill increasein the next few years.After the 1970sthrough extrapolation from smallstudy plots. over-winteringunder favourable conditions, they may have To understandcurrent and likely future trends in the a betterchance of reachingtheir breedinggrounds in Alaska PacificGolden Plover population of Samoa,it is informative and easternSiberia, breeding successfullyand returning. to comparethe results of recentstudies on Hawai'i (Johnson After long over-seaflights - twice flying morethan 9,000 km et al. 2001). There, territorialityhas been studiedintensely, - they will comeback to a winteringarea that is continuously giving furtherinsight into territory size,proportion of terri- improving,offering more andbetter opportunities for feed- torial and non-territorial birds as well as survival rate and ing and roostingin safety. longevity.The fact thatPacific Golden Plovers establish ter- ritoriesin their winteringgrounds was originally reported for ACKNOWLEDGEMENTS Hawai'i by Johnsonet al. (1981). This studyshows that they behave in much the same way on Samoa. Moreover they I wish to thank Mrs Easter C. Galuvao and Mr Sailimalo Pati defend their territories in the same manner as described for Liu, Departmentof Lands,Surveys and Environment, Apia, Hawai'ian birdsby Johnson& Connors(1996). For Samoa, for their supportand interestin this study,and Mrs Norma more detailedinformation is neededon the daily movements and Mr Klaus Stuenzner,Alafua, for their hospitalityand of inland-feedingbirds. They certainlyspend time at other supportthrough many years. places,not only to roost at night, but also to make use of Thanksare alsodue to OscarW. Johnsonwho kindly re- coastalareas accessible during low tide. viewedthis paper and provided valuable comments, sugges- In Samoa,Wandering Tattlers also seemto establishter- tionsand updates. I alsowish to thankthe editor,Humphrey ritories.Future studies might show whether this applies to all Sitters,for his fast andprofessional handling of thismanu- or only a part of the population. script. Population trends might be directly influenced by a Thisresearch was supported by LandesmuseumNatur und changein humanattitudes towards nature and conservation. Mensch Oldenburg. In Samoa,this changeis alreadyapparent. When the author startedhis bird studiesin 1975, the favouritepastime of chil- REFERENCES dren was to kill birds aroundtheir housesand plantations usingslings. Probably this is the reasonwhy PacificGolden Amerson, A.B., Whistler, W.A. & Schwaner, T. D. 1982. Wildlife and Ploversnever used to useshady areas because shade-provid- wildlife habitat of American SamoaII. Accountsof fauna andflora. United StatesDepartment of the Interior. Fish and Wildlife Service. ing structureslike trees,shrubs or housesmight harbour such Washington,D.C. hunters.Recently, killing birdswith slingshas become very Byrkjedal, I. & Thompson, D. 1998. Tundra Plovers: The Eurasian, rare andpeople are more tolerantof sharingtheir lawnsand Pacific and American Golden Plovers and Grey Plover. T. and A.D. gardenswith wildlife. Waders will thus benefit from this Poyser,London. increasingtolerance, leading to whatis describedfor Hawai'i Chapman, A. 1924. The bordersand beyond.E. Arnold, London. as "the remarkable ability of wintering Pacific Golden- Johnson,O.W., Johnson,P.M. & Brunet, P.L. 1981. Winteringbehav- iour and site-faithfulnessof Golden Plover on Oahu. Elepaio 41. 123- Ploversto coexistwith people"(Johnson et al. 2001). 130. Despitethe increasingawareness of natureconservation Johnson,O.W. & Connors,P.G. 1996. (Pluvialis needs,wildlife in Samoais underincreasing pressure along dominica),Pacific Golden Plover (Pluvialisfulva). Pp 1-40 in Poole, much of the coastlines as well as in the mountains. Transfor- A. & Gill, F.(eds).The Birds of North America,No. 201-202. Academy mationof primaryrain forestinto cattle-farms,construction of NaturalSciences, Philadelphia, and American Ornithologists' Union, of roadsacross the islandsand to the hinterlandplantations Washington,D.C. Johnson, O.W., Brunet, P.L., Rotella, J.J., Johnson, P.M. & A.E. hasopened up the denseforest that used to coverthe Samoan Brunet 2001. Long-termstudy of apparentsurvival in PacificGolden- islandsalmost completely. Ploversat a winteringground on Oahu, Hawaiian Islands.The Auk 118 On the Hawaiian Islands,this changeof landscapehap- (2). 342-351. peneddecades earlier (Johnsonet al. 1981, 2001). Pacific Mayr, E. 1945. Birds of the southwestPacific. Macmillan, New York. Golden Plovers have adaptedto this situation,using man- Pratt, H.D., Brunet, P.L. & Berret, D.G. (1987). TheBirds of Hawaii and madehabitats like parks,roadsides and sportsfields next to the tropical Pacific. Princeton,New Jersey. skyscrapers.During the author'snumerous visits to Oahu Watling, D. 1982. Birds of Fiji, Tongaand Samoa.Millwood PressKent: Croom Helm, Wellington. Island, Hawai'i, it has becomeclear that this speciescan Williams, T.C. & Williams, J.M. 1988. Radar and visual observations adaptquickly to thepresence of humans.Golden Plovers are of autumnal(southward) shorebird migration on Guam. TheAuk 105. usingthe roofs of one-storeybuildings and even expect food 460-466.

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