Sporadic occurrence of haemosporidian parasites in two species of marsh terns

Abstract

AbstractVector-transmitted haemosporidians are among the most common parasites in birds, but our knowledge of the inter-specific patterns of infection rates and the parasite community composition is far from complete because of the unequal distribution of the screening effort across bird families and genera. To assess infection rates and the diversity of haemosporidians from the generaPlasmodium,Haemoproteus, andLeucocytozoonin marsh terns, which represent poorly explored in this regard genus of the family gulls, terns, and skimmers (Laridae), we screened two species: the Whiskered Tern (Chlidonias hybrida) and the Black Tern (Chlidonias niger). We sampled these long-distance migratory birds on breeding grounds: the Whiskered Tern in south-central Poland and north-central Ukraine, and the Black Tern – in north-central Ukraine. We found that birds from both species were infected only sporadically, with prevalence at the population level not exceeding 3.4%. Only parasites from the generaPlasmodiumandLeucocytozoonwere detected. There was neither an inter-specific difference nor a difference between populations of the Whiskered Tern in infection rates. In total, we registered three lineages – onePlasmodiumand twoLeucocytozoon– that were previously recorded in other bird species, and two unidentifiedPlasmodiuminfections. One of the lineages (LeucocytozoonLARCAC02) represents a specialist parasite with the host range restricted to larids and geographic range restricted to Poland, and two others (PlasmodiumSGS1 andLeucocytozoonCIAE02) represent generalist parasites with very broad host and geographic ranges. This study reinforces the existing evidence that terns host parasites from generaHaemoproteus,Plasmodium, andLeucocytozoononly sporadically.