Notes on the Occurrence of Shorebird Species in Central Chile During Southward Migration

Notes on the occurrence of shorebird species in central Chile during southward migration

PETER COLLINS1, ROSALINDJESSOP 2 & DORIS GRAHAM3

1RMB4009, Cowes,Victoria, 3922, Australia,e-marl: moonbird@waterfront. net. au; 2phillipIsland Nature Park, PO Box 97, Cowes, Victoria,3922, Australia;314 FalconerStreet, North Fitzroy, Victoria, 3083, Australia

Collins,P., Jessop,R. & Graham,D. 2003.Notes on the occurrence of shorebirdspecies in centralChile during southwardmigration. Wader Study Group Bull. 101/102:56-58.

Publishedreports of the arrivalof Holarcticmigrant shorebirds in the southernhemisphere are rare. On the W coastof SouthAmerica the patternsof bothnorthern hemisphere migration and intra-continental move- mentsare complex and little known. During a visitto Chilein August-September2000 we madeopportunistic countsand observationsof shorebirdsbetween Vifia del Mar (near Santiago)and Chafiaralin the north.At thistime of yearSanderlings, Whimbrels, Ruddy Turnstones and Surfbirds are returning from the northern hemisphere.

INTRODUCTION known at what stageor how quicklythis speciesloses breeding plumage;whether on arrival at or en routeto the non- Duringa visit to Chile in August-September2000, we made breedinggrounds. Further north, a flock of Surfbirdsshowed opportunisticcounts of shorebirdsat various localities 0-50% breedingplumage. The following day a group of betweenVifia del Mar, near Valparaisoand Pan de Azficar Ruddy Turnstoneswere foundin the samearea and these re- National Park, near Chafiaral,988 km furthernorth (Fig. 1). tained a high proportionof breedingplumage, suggesting We countedthe following Nearcftc-breeding migrants: Sand- that they were recent arrivals. The estuaryat Conc6n ap- erling Calidris alba, Ruddy TurnstoneArenaria interpres, pearedto be suitablefor wadersapart from thefact that it was Surfbird Aphriza virgata and Whimbrel Numeniusphaeopus. highly disturbedby people.No shorebirdswere foundthere. We also made observationsof someresident species. La Serena: The beachand promenadeof La Serenaare well knownfor its touristfacilities and are undergoinginten- METHODS sive development.During 4-10 September,daily countsof shorebirdswere conductedalong the sandybeach between Countswere made at varioussites that were accessibleby a the old lighthouseon the corner of Avenue Franciscode small, two-wheel drive car between Vifia del Mar and Pan de Aguirre and Avenue del Mar in Coquimbo a distanceof Azficar National Park. The lengthof time spentat thesesites about 9 km. varied between a few hours at Bahia Inglesa and a week at On 4 September,20-30 Whimbrels and 20 Sanderlings La Serena. were scatteredalong the beach.The following day Whim- Birds were consideredto be recentlyarrived migrants if brelshad increasedto 120. They occurredin smallgroups of they were seento arrive off the sea,observed in an unsuit- no more than six and were very approachable,only flying ablearea for feedingor in an apparentlyemaciated condition when dogsor people came near. as evidencedby abdominalprofile (Wiersma & Piersma A singleHudsonian Godwit Limosa haemastica was seen 1995). Otherindications of recentarrival used were tameness on the estuarynear Coquimbo. and the amount of retained (adult) breedingplumage. The Sanderlingsincreased during the week with severalsmall latter was used with some caution, as some speciessuch as flocks of <20 and one of 150, 5 km further north. None of Sanderlingappear to lose their breedingplumage very the Sanderlingsshowed any breedingplumage but werecon- quickly. sidered to be all adults. Juveniles, with their distinct brown- ish head, would have been easy to pick out. RESULTS Eachafternoon, some time was spentsea-watching and on 7 Septembera groupof 30 Whimbrel was seenflying south Nearctic migrants along the coast.They were not in a cohesiveflock and it could have been a local movement. However, in view of the Vifia del Mar: The coastaround Vifia del Mar and Valpar- small flock-size encounteredelsewhere in the region, they aiso and the industrialarea of Conc6nare highly developed may well havebeen new arrivals.It appearsthat after arrival for tourism,which occupies almost every beach habitat. On they spreadout alongthe coastinto feedingareas occupied 28 August,however, one Whimbrel and three Surfbirds were by singlebirds or small groups. seen in an area known as the Rocks, near the Marine Insti- On 10 September,there were onlyl0 Whimbrel and 50 tute. None of the Surfbirdshad any breedingplumage, so Sanderling on the final count of the beach at La Serena. they may have been non-breeding birds that had over- Apparentlythe birdsthat had arrived in the previousthree winteredin the area(Hayman et al. 1988).However, it is not dayshad movedon, and therehad beenno new arrivals.

Buffetin 101/102 August/December 2003 56 Collins et aL Occurrence of shoreb•rdspecies •n central Chde 57

plumage. The majority of this mixed flock were actively foraging on the rocky shore.In commonwith most of the migratorywaders we hadencountered, these were incredibly tame. Pan de Azficar National Park, near Chafiaral, was vis- Pan de Azucar ited during13-14 September.This is wherethe desertcomes Bahia Inglesa down to the coast.Four separateflocks of Whimbrelswere Punto Ch seenarriving in the late morning and early afternoon.The

La Serena first flock of 16 landedbriefly in an areaof sanddunes and, half an hour later, they were joined by a group of 10 that Coquimbo arrived off the sea. Two other flocks of 8 and 24 arrived 1V2 Vinadel Mar -- hours later and landed 1 km further inland.

Resident shorebirds N Southern Lapwings Vanellus chilensis were present and either breedingor holding territory commonlythroughout suitablehabitats, which varied from marketgardens and open grazedfields to areasof grasslandin cities.We inferredthat the birds were breedingbecause of their aggressivebehav- iour,including distraction display, when approached by people or dogs.This was similarto the reactionof breedingMasked Lapwing V. miles with which we are familiar in Australia. One broodof threewell-grown chicks was found south of La Serenain a field grazedby cattle. American Oystercatchers Haematopuspalliatus were seeninvariably in pairs on most sandy shores,the largest Tierra del Fuego . numberbeing at Pan de Azficar where at least four pairs appearedto be holding territory. Fig 1. Map of Chile showing locationsmentioned in the text. Blackish OystercatchersH. ater were not as commonas AmericanOystercatchers, but two territorialpairs were seen near Los Choros and scatteredpairs and individuals were Punto Choros: On the afternoonof 6 September,during seenon other rocky coastlines. a visit to a HumboldtPenguin Spheniscus humboldti colony A pair of Snowy Plovers Charadrius alexandrinusap- near Punto Choros, 170 km north of La Serena, a flock of 23 pearedto be holding a territory on the beach5 km north of Whimbrel arrived off the sea. The birds did not land on the La Serena as they became agitated when approachedby coast but flew a few km inland. We searched for them, but dogs.Other Snowy Ploverswere also seenon the beach at could not find them. Earlier that day, on the road to Punto La Serena but did not show such behaviour. Near Punto Choros,a flock of 13 Whimbrel were seenapparently roost- Choros,a pair of Snowy Ploversshowed territorial behav- ing in the semi-desert,at least 2 km from the coast. iour similar to that of the close-relatedRed-capped Plover Later on 6 September,another group of 12 Whimbrels Ch. ruficapillusof Australia.Although no nestwas found we flew southwardsalong the coast and may well havebeen new inferredthat the pair had a nestwith eggs. arrivals. Other small groupsof Whimbrels were found near A pair of Rufous-chested Dotterels Ch. modestusand a small lagoonto the southof PuntoChoros town, near the three South American Stilts Himantopusmexicanus were mouth of Quebradelos Choros.When thesewere disturbed, alsofound near PuntoChoros though they did not showany they coalescedinto a singleflock of 33. Thesebehaved simi- sign of breeding.Two of the stiltswere adults;the third ap- larly to the Whimbrelsat La Serena.They were tame and, pearedto be a sub-adultmoulting into its first adultplumage. althoughthey movedaway from people,they did not fly or call in alarm.From our experienceof Whimbrel in Australia, DISCUSSION this is unusualbehaviour; they are normallyfar more wary and vocal. The arrival of Holarcticmigrants in the southernhemisphere In a small wetland about 1 km inland from the mouth of has seldombeen reported.In RoebuckBay, NW Australia, the Quebradelos Choros,we found a group of 80 Baird's for example,arrivals have only beenrecorded on two occa- SandpipersCalidris bairdii. They also displayedsigns of sionsin over 20 yearsof regularobservation (P. Collins, R. recentarrival being very tame andshowing no inclinationto Jessop& C. Hassell,unpubl. information). On the westcoast fly. of SouthAmerica, the patternsof both northernhemisphere Bahia Inglesa near Caldera: On 12 September,we migration and intra-continental movements appear to be briefly visitedthis area,which is beingdeveloped for large- complexand little known (Vilina et al. 1998). scale tourism. It includes a small tidal mudflat where we Previousobservations in the Coquimboarea have shown found 30 foragingWhimbrels. In a rocky areanear the town, similarnumbers and speciesof over-winteringshorebirds to therewas a groupof 60 Surfbirds.The majoritywere adults, thosefound in ourbrief survey(Tabilo et al. 1996).However, having somebreeding plumage, but we consideredthat at we sawneither of the Yellowleg speciesTringa melanoleuca, least four were juveniles. These were in companywith 40 T.fiavipes and no SemipalmatedSandpipers C. pusilla,which Ruddy Turnstones,all of which showed >25% breeding Tabilo et al. (1996) reportedas occurringin "hundreds".The

Bulletin 101/102 A ugust/December 2003 58 Wader Study Group Bulletin

reasonmight be eitherthe continuingdegradation of the area alongthe coastsomewhere between La Serenaand Tierra del through tourism development or the timing of our visit, Fuego. which may have been too early for thesespecies. Ruddy Turnstoneand Surfbird appearto be either at or Bandingstudies have shownthat thereis a populationof close to the southern extent of their destination on the W Sandefiingsthat utilise the shoresof La Serena/Coquimbo coastof SouthAmerica as they do not appearto have been Bay, but patterns of arrival and turnover have only been counted in any numbers further south (e.g. counts of 10 explored to a limited extent (Tabilo et al. 1990). In the La RuddyTurnstones and a singleSurfbird in Tierra del Fuego Serenaarea, Sanderlings show some site fidelity throughthe (Minton et al. 1996)). southernwinter, presumablythese are immature birds that Sallaberryet al. (1996) mentionedSanderling, Whimbrel, are displacedby the adultswhen they returnin the summer. RuddyTurnstone and Baird's Sandpiper as important migra- In SE Australia,banding studies have shownthat individual tory speciesin Chile and proposeda protected area in the Sandefiingsrange along vast stretchesof coast.Flocks are extremenorth of CoquimboBay. They alsooutlined propos- also highly mobile, moving along the beachesbetween the als for various other ecological and conservation-related mouth of the Murray River in SouthAustralia and Shallow activitiesfor studentsand the generalpublic. This forward- Inlet in Victoria, a distance of over 900 km (Gosbell & looking programme can only be applauded and our best Minton 2001.). Sanderlingsprobably behave in much the wishes are with all the shorebird workers of Chile. sameway along the coastof Chile (Tabilo et al. 1990). The Sanderlingsencountered in Chile did not have any REFERENCES breedingplumage and could not thereforebe aged with any degreeof certainty.However, it seemslikely that they were Gosbell, K. & Minton, C. 2001. The biometricsand moult of Sanderling all adultsbecause none had the brownishheads of juveniles Calidris alba in Australia. The Stilt 40: 7-22. (which, as in most arctic-breedingshorebirds, probably mi- Minton, C.D.T., Piersma, T., Blanco, D.E., Baker, A.J., Benegas,L.G., de Goej, P., Manriquez, R.E., Peck, M. & Ramirez, M.S. 1996. grate later than the adults). No ageswere assignedto birds Wader numbersand the use of high tide roosts at the Hemispheric capturednear La Serenaby Tabilo et al. (1990). Relatively Reserve "Costa Atlantica de Tierra del Fuego", Argentina - January larger numbersof Sanderlingshave been countedfurther and February 1995. Wader Study Group Bull. 79:109-114. southin Tierra del Fuego (Minton et al. 1996), and if this Sallaberry, M, Tabilo, E. Klesse, C. & Abarca, J. 1996. The Chilean speciesis as mobile as the Australianpopulation, they could Shorebird Network (RECAP).. International Wader Studies 8:71-78.- easily be the samebirds. Tabilo, E., Jorge, R. Riquelme, R. Mondaca, Labra, A.C. Campusano, J. Tabilo, M. Varela, M. Tapia, A. & Sallaberry, M. 1996. Inter- Whimbrelsappear to passthrough the areaswe visitedbe- national Wader Studies 8: 79-84. causenumbers varied between counts,especially in the La Tabilo, E., Sallaberry, M., & Myers, J.P. 1990. A shorebirdbanding Serenaarea. This, coupled with several flocks observedin programmeat Coquimbo Bay, Chile: some general observationsand apparentlyunsuitable feeding habitat, would suggestthat comments.Wader Study Group Bull. 60: 34-37. they were recentlyarrivals. Whimbrels were rarely seenfeed- Vilina, Y.A. & Gonzalez, J.L. 1998. The migrationroutes of the Tawny- ing, even in more suitablefeeding sites, such as La Serena. throatedDotterel Oreopholusruficollis in Chile: resolvinga complex In Tierra del Fuego, countsindicate that Whimbrels are not jigsaw puzzle. Wader Study Group Bull. 87: 59-65. Wiersma, P. & Piersma, T. 1995. Scoring abdominalprofiles to char- common that far south (Minton et al. 1996). Therefore it acterizemigratory cohorts of shorebirds:an examplewith Red Knots. would seemlikely that someof thesebirds stayin northern J. Field Ornithol. 66: 88-98. Chile with the majority spendingthe non-breedingseason

Bulletin 101/102 August/December 2003