Short communications
Blacksmith Plover Vanellus armatus on Prince Edward Island, Southern Ocean
JOHN COOPER & LES G. UNDERHILL
Arian DemographyUnit, Universityof Cape Town, Rondebosch, 7701, South Africa, e-maih Igu @maths. uct. ac. za
During an ornithologicalsurvey of Prince Edward Island Corre & Probst1997). EuropaIsland is 530 km from cont- (46ø38'S37ø45'E) (Crawford et al. in prep.),we encountered inentalAfrica. Another,age not specified,was recorded on an adult Blacksmith Plover Vanellus arrnatus on 19 Decem- PossessionIsland in theCrozet Archipelago from 22 August ber 2001 in AlbatrossValley (Figs 1 and2). It wasfirst heard to 3 November 1982 (Stahl et al. 1984). callingand foraging among short grass, but tookflight on our Blacksmith Plovers occur in sub-Saharan Africa south of approach when it was harassed by Subantarctic Skuas a line betweenKenya and Angola (del Hoyo et al. 1996). Catheractaantarctica. It wastherefore unexpected when we Duringthe firsthalf of the 20th century,the range expanded encounteredwhat musthave beenthe samebird againtwo southwestwardsby about 1,000 km towards the Western dayslater at R.S.A. Point, about I km distantfrom the place Cape (Ward et al. 1997). The farthestknown movementof whereit wasfirst seen.Prince Edward Island, along with the a tinged bird is 131 km (Underhill et al. 1999), but this does nearbyMarion Island,is c. 1,800 km from the closestpoint notreflect the extent to whichBlacksmith Plovers normally on the African continent,Port Elizabeth(Fig. 1). move becausethey exploit ephemeralhabitats. Their pre- This is the first record of Blacksmith Plover for the Prince ferredhabitat is moist, shortgrassland and mudflatson the EdwardIsland group (Newton et al. 1983,B.M. Dyer in litt.), edgesof waterbodies;the availabilityof this habitatis sea- and the third recordfor southernhemisphere islands in the sonaland rainfall-dependent, especially in the middle of its African sector of the Atlantic, Indian and Southern Oceans. range. In Zambia, Zimbabwe and Botswana, Tree (1980, An immature was seen on Europa Island, in the southern 1998) and Ward et al. (1997) showedthat numbersof Black- MozambiqueChannel (Fig. 1), from 27 to 29 May 1994 (Le smithPlovers fluctuate widely according to habitatavailabil-
ß Ascension Island Seychell;sos
ß St Helena
ß Roddgues Island
EurIsland3a•..j ] Reunion
ß Tristan da Cunha ß ß Gough Island Amsterdam Island & St Paul Island Crozet Islands AlbatrossValley ß Kerguelen PrinceEdward__ //R.S.A. Point Prince Edward Island• Islands ß ß Bouvet Island Heard & McDonald Islands
Pdnce Edward Islands
Fig. 1. The African sector of the Southern Ocean; the three islands at which Blacksmith Plovers have been recorded are underlined
47 Bulletin 97 April 2002 48 Wader Study Group Bulletin
Fig. 2. Adult BlacksmithPlover in AlbatrossValley on Prince Edward Island;the bird in the foregroundis a WanderingAlbatross Diomedia exulans chick.
ity in responseto rainfall eventsover broadareas, and they Del Hoyo, J., Elliott, A. & Sargatal, J. (eds.) 1996. Handbook of the must therefore undertake substantial nomadic movements. In birds of the world. Vol. 3. Hoatzin to Auks.Lynx Edicions,Barcelona. southernMozambique, Parker (1999) showedthat Black- Le Corre, M. & Probst, J. M. 1997.Migrant andvagrant birds of Europa lsland (southernMozambique Channel). Ostrich 68: 13-18. smith Plovers have a strong seasonaloccurrence pattern. Maclean, G.L. 1993. Roberts' birds of southernAfrica. John Voelcker They aremost abundant in the driestmonths, July to Septem- Bird Book Fund, Cape Town. ber, which suggeststhat they leavethis region once the rains Newton, I.P., Adams, N.J., Brown, C.R., Enticott, J.W. & Fugler, S. begin. R. 1983. Nonmarinevagrant birds at the Prince Edward Islands,June There is evidence that Blacksmith Plovers prepare for 1981-May 1983. Cormorant I l: 35-38. these nomadic movementsby acquiring fuel stores.The Parker, V. 1999. The atlas of the birds of Sul do Save,southern Mozam- bique. Avian DemographyUnit. University of Cape Town. and Endan- averagemass of BlacksmithPlovers is 158 g (Maclean1993). geredWildlife Trust, Cape Town and Johannesburg. Birds weighingin excessof 200 g havebeen found, and the Stahl, J-C., Weimerkirsch, H. & Ridoux, V. 1984. Observations maximumrecorded is 226 g (Summers& Waltner 1979). In rEcentes d'oiseaux marins et terresires visiteurs dans les Iles Crozet, describingthese heavy birds, Tree (1998) said: "The accu- sud-ouestde l'Oc6an Indien. Gerfaut 74: 39-46. mulated lipids on the breastwere very obviousto the feel". Summers, R.W. & Walther, M. 1979. Seasonal variation in the mass of Fuel reservesexceeding 30% of averagemass would be suf- wadersin southernAfrica, with specialreference to migration.Ostrich 50: 21-37. ficient to enable a Blacksmith Plover that had been blown Tree, A.J. 1980. Migration as an ecological adaptationin the central over the oceanby a weathersystem to stayaloft for at least African Charadrii. Honeyguide 102: 16-25. 41 hours (Summers & Waltner 1979). At 50 kin/hour, a Tree, A.J. 1998. Movements of Blacksmith Plover in south-centralAfrica. plover could cover more than 2,000 km in that time. Honeyguide 44:199-203. Therefore,given that BlacksmithPlovers acquire suffi- Underhi!l, L.G., Tree, A.J., Oschadleus, H.D. & Parker, V. 1999. cient fuel to undertake extensive movements within south- Review of ring recoveries of waterbirds in southern Africa. Avian ernAfrica, andgiven that these movements must have a large DemographyUnit, University of Cape Town, Cape Town. Ward, D., Underhi!l, L.G. & Tree, A.J. 1997. Blacksmith Plover nomadiccomponent because they are searchingfor ephem- Vaneflus armatus. In: Harrison, J.A., Allan, D.G., Underhill, L.G., eral habitats,it is not surprisingthat they occasionallyoccur Herremans, M., Tree, A.J., Parker, V. & Brown, C.J. The atlas of as vagrantson the offshoreislands of the oceansadjacent to southernAfrican birds. BirdLife South Africa, Johannesburg:396- their continentalrange. 397.
Crawford, R.J.M., Underhi!l, L.G., Bester,M.N., Cooper,J., Greyling, M.D., Meyer, M.A., Petersen, S., Ryan, P.G. & Wilkinson, W. in prep. The PrinceEdward IslandsMillennium Expedition.South Afri- can Journal of Science.
Bulletin 97 April 2002