Tapeworm bolus expelled from New Zealand variable oystercatchers (Haematopus unicolor) during handling: first record of this phenomenon in wild birds, and a global checklist of Haematopus cestode parasites.

On two occasions in November and December 2009, whilst being captured and handled for banding in Tasman Bay, New Zealand, two variable oystercatchers (Haematopus unicolor Forster, 1844) voided a number of cestode strobilae from their cloaca. Their morphology indicates that they belong to the family Hymenolepididae, confirmed by BLASTn searches of large and small subunits of ribosomal DNA partial sequences (18S and 28S, respectively). However, they cannot currently be assigned to any species reported for any oystercatcher species from New Zealand nor from oystercatchers worldwide. We present a checklist of all cestode parasites reported in the literature for Haematopus species, along with their sources and synonyms. While the taxonomy of New Zealand oystercatchers is currently uncertain, more detailed knowledge of the parasite fauna of this bird group may help to elucidate the historical biogeography of the oystercatchers. The means of collection of these tapeworms is unusual and does not appear to have been reported in the literature previously.