A review of global diversity in avian haemosporidians (Plasmodium and Haemoproteus: Haemosporida): new insights from molecular data

Abstract

Biogeographic patterns of parasite diversity are useful for determining how host-parasite interactions can influence speciation. However, variation in methodologies and sampling effort can skew diversity estimates. Avian haemosporidians are vector-transmitted blood parasites represented by over 1300 unique genetic lineages spread across over 40 countries. We used a global database of lineage distributions for two avian haemosporidian genera, Plasmodium and Haemoproteus, to test for congruence of diversity among haemosporidians and their avian hosts across 13 geographic regions. We demonstrated that avian haemosporidians exhibit similar diversity patterns to their avian hosts; however, specific patterns differ between genera. Haemoproteus spp. diversity estimates were significantly higher than those of Plasmodium spp. in all areas where the genera co-occurred, apart from the Plasmodium spp.-rich region of South America. The geographic distributions of parasite genera also differed, with Haemoproteus spp. absent from the majority of oceanic regions while Plasmodium spp. were cosmopolitan. These findings suggest fundamental differences in the way avian haemosporidians diverge and colonise new communities. Nevertheless, a review of the literature suggests that accurate estimates of avian haemosporidian diversity patterns are limited by (i) a concentration of sampling towards passerines from Europe and North America, (ii) a frequent failure to include microscopic techniques together with molecular screening and (iii) a paucity of studies investigating distributions across vector hosts.

Prevalence of haemosporidians in a Neotropical endemic bird area

“…To separate these two lineages we would probably need to include additional molecular markers or to increase the size of the cytochrome b fragment sequenced. Given the small sample size of the birds screened in the present study, the number of lineages found is a considerable value and is comparable with other studies in the Neotropics that have found a large number of lineages (Fallon et al 2005, Lacorte et al 2013, Clark et al 2014. The high species richness we report agrees with the hypothesis that haemosporidian diversity may be a function of avian and/or vector host diversity, both of which are high in tropical continental regions (reviewed in Clark et al 2014).…”

“…The recent methodological advances in the detection of avian haemosporidian infection have led to an increase in the number of published surveys across the world (reviewed in Clark et al 2014). Some biogeographical patterns of haemosporidian distribution have been inferred.…”

“…For example, continental avian diversity hotspots tend to have higher avian haemosporidian species richness estimates compared to non-hotspots. Another interesting pattern is that continental South America harbours the largest number of lineages of both Plasmodium and Haemoproteus (Clark et al 2014). However, much of the research that has been done is restricted to European and North American passeriform communities, and only a few sites have been sampled in continental Neotropics (Lacorte et al 2013, Clark et al 2014, González et al 2015, Marzal et al 2015.…”

Investigation of avian haemosporidian parasites from raptor birds in Turkey, with molecular characterisation and microscopic confirmation

“…Avian haemosporidian parasites are transmitted by biting midges, louse flies, black flies and mosquitoes (Valkiūnas 2005). More than 250 species of avian haemosporidians have been described and named according to morphological characteristics of parasite blood stages, and over 2 000 unique genetic haplotypes have been identified and recorded by molecular studies (Valkiūnas 2005, Clark et al 2014). Because these blood parasites are abundant and diverse, they constitute excellent model organisms for the study of wildlife parasitology and have been the focus of research efforts for over 100 years (Valkiūnas 2005, Bensch et al 2013.…”

Prevalence of Pseudo-malaria (Haemoproteus spp.) Infection in Many Species of Birds

“…In other avian species, anemia and anorexia have been reported occasionally (8,14). Importantly, new records of Haemoproteus are discovered constantly and should still be monitored for effects on host condition (15).…”