Molecular characterisation of haemoparasites in forest birds from Robinson Crusoe Island: Is the Austral Thrush a potential threat to endemic birds?

SummaryThe Juan Fernández Firecrown Sephanoides fernandensis and Juan Fernández Tit-Tyrant Anairetes fernandezianus are two endemic forest birds inhabiting Robinson Crusoe Island and are classified as ‘Critically Endangered’ and ‘Near Threatened’ respectively by IUCN. Previous research concluded that the two main factors involved in the decline of these birds were habitat degradation and the introduction of predator / competitor species. However, the potential role of parasitic diseases has not yet been explored. In order to explore hypothetical host-switching phenomena, we genetically identified the haemoparasites present in four bird species, the two endemic species mentioned above and two recent colonisers, Green-Backed Firecrown Sephanoides sephaniodes and Austral Thrush Turdus falcklandii. We failed to find infections by different blood parasites (Plasmodium, Haemoproteus, Leucocytozoon, Trypanosoma, Babesia and Isospora) in the endangered Juan Fernández Firecrown. However, the Juan Fernández Tit-Tyrant was infected with some parasites shared with the Austral Thrush. The latter species may function as a key-host species on the island as it showed both the higher hemoparaasitic diversity and prevalence. The role of Green-Backed Firecrowns is apparently of lower importance because only one individual was found parasitized. The Austral Thrush could be responsible of the introduction of some parasites also isolated from the Juan Fernández Tit-Tyrant and represent a potential threat to the endemic firecrown due to its role as a reservoir. The spread of Austral Thrushes could increase the contact between species, increasing the probability of a switching event.

A new genus of the family Hymenolepididae (Cestoda) from Sephanoides sephaniodes (Apodiformes, Trochilidae) in Northern Patagonia (Chile)

A new species of hymenolepidid cestodes from Sephanoides sephaniodes (Trochilidae) found in Chile is described. The most characteristic features of Colibrilepis pusilla gen. nov., sp. nov. are the lack of rostellum, a cirrus sac with a thick-walled distal end (separated by a constriction) and protruding into genital atrium, a thick-walled saccular uterus filling entire median field of the gravid proglottis and the small number of eggs containing thick walled embryophores with polar swellings. Staphylepis is the most similar genus but differs in its apical structure because of the presence of a rudimentary rostellum. Moreover, molecular phylogenetic analyses show that Staphylepis and Colibrilepis are not sister taxa.