Trematode Anklets on Procellariform Seabirds from Southern Africa and the Adjacent Southern Ocean

Abstract

Claugher (1976) and Imber (1984) reported the incidence of anklets around the tarsi of seabirds at the Chatham Islands (44S, 176W). The anklets were comprised of the larvae of a trematode Copiatestes filiferus (Gibson & Bray 1977) which presumably became tangled around the legs of the seabirds as the birds fed on the euphausiid host of the trematode (Imber 1984). Trematode anklets caused considerable Whitefaced Stormpetrel Pelagodroma marina mortality at the Chatham Islands during 1970, when anklets linking the tarsi become tangled in terrestrial vegetation (Claugher 1976, Imber 1984). During this event, anklets were found on six seabird species (Claugher 1976), but at other times they only have been reported from Whitefaced Stormpetrels, Leach's Stormpetrels Oceanodroma leucorhoa and Fairy Prions Pachyptila turtur (Imber 1984). Anklets have been reported from Whitefaced Stormpetrels at Gough Island (40 21s, 9 53W), but no instances of death from entanglement have been recorded (Clancey 1981, Furness 1984). This study reports the incidence of trematode anklets on 26 species of procellariiform seabirds found off southern Africa and in the adjacent region of the Southern Ocean.